Home

ETW User Guide

Contents

1. p ag yn o USER GUIDE ht Re per Ca 19 m 6 w lt 1 F w dg C M tr d k i 2 m gt 2 e n m Ms m 6 NE m VES e 7 KFrrrrrrrryr a nn SUMMARY This guide is to give prospective users of the European Transonic Windtunnel an introduction to the facility an insight into its capabilities the procedures employed and the services offered The intention being that it will enable the prospective user to assess the tunnel performance against his program me requirements Report Number ETW 0 95001 Original Issue Feb 1995 Revision A Jan 2004 Compiled by U Walter Approved by G Hefer Authorized by W Burgsm ller Copyright ETW GmbH ETW GmbH has sole copyright of all the contents of this document which must therefore not be copied or reproduced in anyway without the prior written permission of ETW GmbH 1 INTRODUCTION 11 E a 2 1 2 Basic 3 1 3 00 00 3 1 4 purpose of he Guider 222222 3 2 DESCRIPTION OF THE FACILITY 2 1 EW Characteristics oee e 5 2 2 Aerodynamic 2 6 DN Flow 7 2
2. 2 pU Test Section Top Wall Maraging Maraging Maraging Copper Maraging Maraging Maraging Material Grade 250 Grade250 Grade250 Grade250 Grade 250 250 Manel 18 Component ad Balance m zu Component as Balance Combined Loading Balance Balance Single Loading se Dr ES s 5 mn vo e erster ve va ve ran m roo gt lt e A lt ETW European Transonic Windtunnel User Guide 43 q X a 2 n n 4 List of Abbreviations AC ADC AIU AVS AWG BCD BCM CFD CMOS CRB CU DAS DC ESP ETSR FRS HSDAS ETW Europear Alternating Current Analogue to Digital Conversion Analogue Input Unit Anti Vibration System American Wire Gauge Binary Coded Decimal Balance Calibration Machine Computerized Fluid Dynamics Control and Monitoring System Cart Rigging Bay Conditioning Unit Data Acquisition System Direct Current Electronically Scanned Pressure Enhanced Twin Sting Rig Flow Reference System High Speed Data Acquisition System Instrumentation Cabin Inclinometer Conditioning Unit Input Output Multi Channel Conditioning Unit MDA M
3. X days for the test dependent on the test programme incl configuration changes in a VICR 1 day in a CRB for post check and removal from cart lor 2 days in the Model Preparation Room for disassembly and packing 6 weeks to issue the test report These durations are only indicative and reflect the possibility of large variations according to the no velty and complexity of the test ETW 13 wasa p La 2 2 Z m E European Transonic Windtunnel User Guide 4 1 Test Objectives Flight Reynolds Number Testing The test objectives selected by the client defi ne the type of model to be used in ETW Full span mo dels will be used on various sting supports whilst half models are attached to the test section top wall of model cart The limiting parameter for the size of transport aircraft models is typically the span criteria i e model span lt 65 of test section width span lt 0 65 x 2 4 1 56 m For fighter and space vehicles the tunnel blockage criteria is often the decisive para meter i e model cross section lt 0 5 of tunnel cross section Transonic half models typically will be restric ted in half span to 65 of tunnel height 0 65 x 2 0 m 1 30 m Low speed high lift models might increase the span criteria to 75 ETW will provide all inputs necessary to establish well selected and optimized type of model With full span m
4. Tunnel Hall Test Section wall pressures Model Cart 1 Model amp Top Wall pressures Model Cart 2 Model amp Top Wall pressures Cart Rigging Bay Model Preparation Instrumentation Lab Transducer Calibration All of these systems can easily be reconfigured to be tailored to particular application large ber of plug in modules with different functions and ranges are therefore available After evaluating the performance of the stan dard PSI system in cryogenic environment ETW sug gested number of modifications in the interfacing between the multi port sensors and the 8400 System Processor These resulted in a drastically reduced wire count longer calibration intervals and improved data quality The present configuration includes small ESP size Scanner J unction Unit which should be mounted in the vicinity of the sensors On the System Processor side new 584 Unit including power supply has been added For the model mounted multi port modules ETW has standardized on the PSI high density electro nically scanned pressure ESP series with 64 transdu cers ETW carries several of these units with ranges from 17 kPa to 310 kPa which are available for client use if required Model pressure measurements are essentially differential so they require reference pressure which must be stable and accurately known As the hydrosta tic pressure difference between Instrumentation Cabin
5. rect voltage and strain gauge with AC or DC coupling The system is capable of measuring at sampling rate of up to 100 000 samples per second irrespective of the number of channels being recorded The system is fully integrated into ETW s data acquisition system and is under the control of the High Level System In addition to the data acquisition the system comes complete with its own extensive data analysis and reporting software Standard processing procedu res allow signal manipulation and analysis and display of the data all of which can be performed in the time and frequency domain Extensive interactive graphical tools and analysis automation provide an objective measurement system Test results can be quickly com pared with previous data The data processing 15 ported by extensive QA tracking through data history recording and the use of the integrated Project Mana ger The results can be exported in various formats and can if required be tailored to suit the client s indivi dual needs Analogue Inputs 32 Single Ended 0 1 mV to 0 10 V Up to 26 5 kHz Programmable Selection 1 2 4 8 10 80 100 800 Filter Bandwidth AG DC coupling Programmable Gain 1 000 4 000 Programmable Offset 6V applied after first stage gain ADC Resolution 16 bits Sampling Rates 100Hz to 100kHz Transducer Excitation 0 15 V in 50 mV steps Table 8 Characteristics of the High Speed DAS 35 w 36 6 2 6
6. wing procedures are standard during assembly Bolt torque sheets defining the bolts used the quantities size required torque values locking method and any special treatment Model inspection sheets for listing of inci dents occurring during the test run Model balance misalignment sheets with defi nition for measurement of mechanical mis alignment and electrical offset for any incli nometer used in the test assembly Optical identification forms to verify the ob servation of test assemblies These forms are used by the responsible test engineer in close co operation with the client model rigging personnel Further quality checks are performed on special applications Transition band quality is checked care fully prior to and after each test run In critical cases the density of the used particles is defined with a counting method to identify the particle density per mm2 This guarantees the high quality and repeatabi lity of transition bands used on the model Filling methods require special treatment of the bolt holes A mechanical anchoring is necessary if Cer robend is used Due to severe pressure changes in the test section any enclosed air has to be avoided to en sure that the filling stays inside the hole Surface roughness measurement is a standard procedure prior to any high Reynolds number test cam paign A careful inspection of the critical surfaces of the model both prior to and after the test r
7. Temperature Measurement Channels For cryogenic facility such as ETW the need for the measurement of large number of temperatures is self evident In principle ETW has standardized on three types of temperature sensors for Data Acquisition Instrumentation Pt 100 RTD Type T Thermocouples Semiconductor Diodes Each have their own field of application and their particular signal conditioning 6 2 6 1 Platinum 100 Resistance Thermometry Devices Pt 100 RTD s are used where high accuracy and good long term stability are required For that reason the FRS total temperature sensors and the ten sensors on the ETW balances are Pt 100s Due to the consider able influence of temperature on cable resistance ETW uses a four wire configuration per sensor and a high ac curacy constant current supply of 1 mA The latter is created by inserting a special current module in the patch lead on the input patch panel and measurement is by way of a standard Conditioning Unit 6 2 6 2 Type T Thermocouples In principle ETW has standardized on the use of Type T Copper Constantan Thermocouples for those multiple applications where the requirements on accu racy and long term stability are less severe than above Type T Thermocouples show the most consistent beha viour at cryogenic temperatures The sector model support cabling includes 24 channels of Type T exten sion wire ETW favours the use of floating equithermal referen
8. i 4 175 0 750 30 1456 250 0 41 5 0 15 0 50 ala y SW 1 5 40 ETW European Transonic Windtunnel User Guide 2871 5 Sting Boss Flange 2871 5 _ LONG STRAIGHT STING Z STING 2945 3 45 558 FIN STING 51454 FIN STING 2818 76 1349 1449 25 EX SSS 1203 331 1449 LONG ADAPTER 2 5 STING LONG ADAPTER STING ADAPTER OFFSET STING SHORT ADAPTER 9 CRANKED STING N gt lt e lt 2 2 02 528 de Gui Windtunnel User ni n Transo ETW 12 ETW Balance 001 8002 B003 8005 8008 ETW Balance 7 A 2xd 0 12x 105 TWIN STING RIG BOOM BALANCES an 38029 Ei 32972 8 am 400 5 SIDE VEN 33 032 3298 3 3 04 4 33 03 58 58 01 VIEW STING SIDE VIEW MODEL SIDE ETW Balance B006 HALF MODEL BALANCE Overall Length 365 220 Max Outer Dla 52 BALANCE CENTRE
9. system second throat supersonic nozzle in order to perform the test runs start up set point changes set point maintaining during polars shutdowns with a high level of safety and economy These activities are usually controlled in automatic mode with the possibi lity of manual interventions from the main tunnel con trol room figure 9 The second unit the Model Hand ling Control synchronizes the activities of other sub systems cart transporter remotely operated doors purging system temperature conditioning system and generally provides the capability to perform auxiliary tasks Figure 9 Main Tunnel Control Room 2 6 Monitoring System The monitoring system allows the operators to observe all the components of the plant and to analy se the behaviour of the main parameters It provides for real time observation can send alarms if failures are detected and gives details of the reasons for failu re It is able to relay necessary information to the con trol system in order to increase the safety level The Control and Monitoring Systems CMOS are extremely reliable and user friendly Through the use of computer screen images and a screen pointing device operators can easily access nearly every control or monitoring parameter throughout the facility 2 1 Data Systems Instrumentation The ETW data systems ensure both the strictest confidentiality of test results and the flexibility and comfo
10. Differencing 29 5 2 2 3 Integration of Third Party Test Data 29 5 2 DataRresentalon a 29 5 2 3 1 Numerical Presentation 29 5 2 3 2 Graphical Presentation 29 b TEST SYSTEM DETAILS 6 1 Model supports n s 31 6 1 1 Models Carts 31 oa Model Facility 31 E 31 6 2 Instrumentation 32 62219 BALANCES sa tn at As 32 6 2 1 1 Balance Calibration Facility 32 6 2 2 Model Attitude Measurement 32 6 2 3 Multi Port Pressure System 33 6 2 4 Flow Reference Systems 33 6 2 5 Signal Conditioning Equipment 34 6 2 5 l Condition 34 6 2 5 2 Calibration Generator 34 6 2 5 3 Multi Channel Conditioning Unit 35 6 2 5 4 Multi Channel RMS Converter 35 6 2 5 5 nnmnnn n 35 6 2 5 6 High Speed Data Acquisition 35 6 2 6 Temperature Measurement Channels 36 6 2 6 1 Platinum 100 Resistance TinermometryDevcos 2 36 6262 Type ienmocsoupnl esia 36 6 2 6 3 Semiconductor Diodes 36 6 2 7 Model Support Cabling 36 APPENDIX 1 Examples of Plot Layouts and Output Styles for Test 5 38 APPENDIX 2 Model Support Components Stings etc 41 APP
11. ETW s software tools which may be used by the client himself or operated by an ETW staff member upon request Printers in the User Room and in the MTCR allow printing and plotting of the test data During wind tunnel run when the client has access to the MTCR online data is displayed on num ber of monitors as numerical and graphical output If so desired immediate analysis including the compari son with results of previous runs or test campaigns can be performed in parallel Constants Sct File and Record Names Processing phoma Nach Nusriser Correction Flow Arpulariey Correction Pressure Cirasiscnt Correction 5 2 1 Data Reduction The standard data reduction program PolProc performs the conversion from signals to physical units the computation of flow parameters loads coeffi cients etc and the application of corrections It can operate in real time synchronized on polars or in an interactive mode Although it works with predefined arrays for each transducer category specific require ments can be satisfied by means of predefined files which are included during program compilation The quantities of the raw data file are assigned to the program internal array elements using Input Se lection Tables see figure 24 thus enabling the pro gram at run time to read the measured data from the file The results computed by PolProc are written to the results data file usin
12. dynamic signals the RMS value is of prima ry interest therefore each MDA system includes two 8 channel units with a bus compatible digital output Its inputs can be connected to the output of a regular CU a MCCU or any other high level source If necessary available high pass low pass or band pass filters can be included in this link As typically these signals are of a fluctuating nature each channel has its own inte grating type ADC with variable time base The following specifications apply Bandwidth 1 Hz to 30 kHz Range 0 to 8 000 mV Accuracy 196 at Crest Factor 3 Integration time ADC 50 ms to 5 5 Overload detection Analogue RMS Output Table 7 RMS Converter Specification 6 2 5 5 DAS Interface The link between the multi access signal condi tioning data bus serving the above mentioned devices and the parallel input output 10 of the acquisition computer is formed by a unit called the DAS Interface It performs such diverse functions as High Speed Data Acquisition In addition to the steady state and quasi dyna mic systems stated above ETW can offer a fully digital High Speed Data Acquisition System HSDAS to gather data from fast response transducers The HSDAS is a PC network based intelligent da ta acquisition system with 32 input channels and pro vision for expansion to 64 channels The unit provides a fully programmable signal conditioning front end with a full range of signal input options including di
13. the ETW Test Section ETW 07 w 02 key element of ETW is the efficiency at which the clients can be accommodated in the facility their models prepared and the speed and accuracy at which the data can be acquired The achievable productivity can be expressed as 3000 polars per year utilizing the present two model carts Various activities such as mo del preparation cart rigging model testing model configuration change model conditioning and check out can take place in dedicated rooms in parallel The general layout of the building is consistent with the possibility of interleaved operations in order to achieve both efficiency and confidentiality Once lifted from a Cart Rigging Bay CRB the transporter can move and lower the model cart assem bly into any of the other rooms along the transfer hall including the test section of the tunnel figure 7 Norm Tear 8 5 Figure 7 Section through Transfer Hall This transfer hall consists of two sections one above the CRBs at ambient air conditions and the ot her above the Variable Temperature Check out Rooms VTCRs and the test section this part of the hall con taining ambient temperature dry air to prevent frost and ice build up when the model and cart assemblies are cold The two sections of the transfer hall are separa ted by
14. 4 Model Handling and Productivity 7 2 5 Wind Tunnel and Model Handling Contreli Systems 8 2 6 Monitoringesystem 9 Del Data Systems and Instrumentation 9 3 TEST CAMPAIGN ORGANISATION AND MANAGEMENT Sill Initial Contact Testing Contract 11 3 2 Security and Client Confidentiality 11 32241 11 3 2 2 Computer and Data Systems 12 3 3 Quality Ass rance 2 ME 12 3 4 ON Sei ces mima 13 3 5 Survey of Testing Operations 13 4 TESTING IN ETW 4 1 Test Ohjectves 15 4 2 Measurement Capabilities 16 4 3 Complementary Testing Techniques 18 4 4 Model Design and Manufacture 20 4 5 Test o A e 21 4 6 Testakreparation 22 4 7 Model Handling Procedures 22 5 DATA ACQUISITION AND DATA PROCESSING 5 1 Model Data Acquisition 25 5 2 DatagRnocessin 21 2 1 an n n 27 5 2 1 1 Computation of Flow Parameters 28 5 2 1 2 Determination of the Model Position 28 5 2 1 3 Computation of Model Loads 28 5 2 1 4 Processing of Autonomous Transducers 28 5 2 1 5 Processing of Pressure Transducers 28 92 1 COMSCORE e EE 28 29 5 2 2 mtina 29 5 2 2 2 Data Interpolation and
15. Data Acquisition System HSDAS is available compatible with the acquisition of signals from fast response instruments such as Kulites Addi tional details are provided in Section 6 2 Anti Vibration System AVS In many wind tunnels the testing of full span models suffers from vibrations of the test object which Boeke ta Ba 2 B EX E EK Zum port can be excited by different mechanisms Although the se phenomena are known from conventional wind tun nels cryogenic tunnels seem to be particularly prone to model dynamics due to very low structural damp ing and the low viscous damping at high Reynolds numbers in connection with high dynamic pressures at these conditions At ETW it has been shown by modal analysis of the support structure and further measurements on the model suspension system that the vibratory system is essentially represented by spring mass system con sisting of the sting internal balance model arrange ment To minimize the effects of model dynamics an active anti vibration interface for full span model testing located between sting and balance has been developed by ETW in co operation with the German company ERAS GmbH The active interface operates on the basis of counteracting vibrations at the eigenfre quencies of the model balance assembly by exploiting the resonance properties of this system Examples of the effec
16. ENDIX 3 Overview of ETW Balances 43 APPENDIX 4 LIS OF on Se 44 ETW 2 2 U 01 2 U E 2 ETW European Transonic Windtunnel The European Transonic Windtunnel GmbH ETW was founded on 28 April 1988 by four European countries France Germany Great Britain and The Netherlands ETW GmbH is a company with limited liability according to German law and its seat is located close to the Cologne Bonn airport in Cologne Germany The objective of the Company was to construct operate maintain and further develop a high Reynolds number transonic wind tunnel facility After many years of joint preparatory investigations and prelimina ry design work the final design of the wind tunnel plant and selection of major mechanical and civil contractors was accomplished in 1989 Con struction work started early in 1990 and at the end of 1992 the facility was completed Since 1995 after careful commissioning and calibration ETW has been in full operation and has in numerous test campaigns proved to meet the design specifications ETW provides high quality wind tunnel test data at actual cruising flight Mach and Reynolds numbers and is open to clients from all over the world User Guide 1 2 Basic Aspects The original motivation to build facilities for flight Reynolds number simulation of aircraft models was based o
17. a transfer lock which enables the purging of all humid air from the model and cart assembly prior to moving into the dry air areas of the facility The 5 are also fed with dry air which can be varied in temperature from 313 K down to 110 K The VTCRs are divided into two main areas by means of large horizontal sliding doors the Temperature Condi tioning Room TCR for the model cart above these doors and the Quick Change Room QCR below the doors figure 8 The receives the model and the front end of the model support system and provides the possibility of conditioning just the model for quick configuration changes between two runs without changing the temperature of the complete cart ETW Figure 8 Section through VTCR The activities that can be undertaken in the QCRs are model configuration changes model instrumentation checking in cold con ditions specific calibrations requiring the model to be immersed in the cold including loads appli cation investigation of the effect of transient condi tions on test data temperature conditioning of model and cart ready for testing 2 5 Wind Tunnel and Model Handling Control Systems Two separate control systems enable the opera tors to manage the different activities of the whole plant The first unit the Windtunnel Main Control WMC synchronizes the activities of the sub systems compressor drive nitrogen injection system blow off
18. abilities in pressure temperature and Mach number stability result in Reynolds number stability of better than ARe lt 0 005 x 10 As far as the flow direction in the test section is concerned ETW achieves deviation of less than 0 1 degree repeatable and measurable to within 0 01 degree High Reynolds number simulation requires the turbulence intensity in the test section not exceeding 0 05 This ambitious goal is achieved by using 4 screens and honeycomb of large depth cell diameter ratio in the stilling chamber and nozzle contraction with 12 to 1 ratio 2 4 Model Handling and Productivity In order to meet the productivity goals ETW has developed removable model cart system for operation in the cold environment Along with the model and its supporting structure model cart consists of the test section top wall the pressure door hatch cover of the tunnel and the instrumentation cabin figure 5 This entire assembly of approximately 200 tonnes is remo ved in one unit by the remotely controlled model cart transporter Two model cart assemblies are provided for full models By exchanging the slotted test section top wall with solid half model top wall including turn table and an external five component balance one of these model carts can be modified to accept vertically mounted half models figure 6 mer i ka ar ee _ _ Figure 6 Half Model
19. and model can be up to 1 kPa ETW utilizes high curacy absolute transducer on the tunnel centreline in the sting boss as a reference Needless to say the ESP sensors and 5 U have to be mounted in heated box in cryogenic model Spe cial purpose controllers to that end are available 6 2 4 Flow Reference Systems ETW has developed special purpose Flow Refe rence Systems FRS for establishing the pressures and the temperatures necessary for calculating the funda mental flow parameters such as Mach number M dy namic pressure q flow velocity V and Reynolds number Re with the required accuracy Its data are used both for automatic control of the facility and for data ac quisition Due to this dual purpose use two indepen dent IEEE 488 interfaces are provided each giving out puts in fully corrected engineering units at sampling rate of 10 Hz ETW utilizes three Flow Reference systems Two are permanently installed in the Tunnel Hall and the third which also supports remotely located transdu cers 15 extensively used in the Instrumentation Cabin during tunnel calibration and for special tests in the laboratory The two FRS systems located in the tunnel hall are used for tunnel operation and are mounted on either side of the test section To avoid the difficulty involved in correcting hydrostatic errors both are mounted at tunnel centreline level and use only hori zontal pneumatic tubing to the Pt and Ps pre
20. ansport aircraft and up to 90 million with vertically mounted half models semi span about 1 3m The operating range expressed as Reynolds number vs Mach number is presented in figure 1 8 8 ha 5 i D 02 04 08 08 10 12 Mich Number Figure 1 Performance Envelope of ETW ETW has advantages over conventional wind tunnels other than the increase in Reynolds number in that the Mach number Reynolds number and dynamic pressure can all be varied independently This capabili ty allows the following test trajectories to be accom plished Reynolds number effects can be obtained wi thout varying the aeroelastic distortion of the model This is achieved by changing only the temperature whilst holding Mach number and pressure and there fore dynamic pressure constant An example of the trajectory of such a test is shown on the operational envelope in figure 2 This feature enables Reynolds number extrapolation for a model where full scale Rey nolds numbers cannot be attained ETTE DE uc Figure 2 Example for Test Trajectories for Reynolds Number and Aero elastic Effects Holding Mach Number Constant M 0 9 Pure Mach number effects can be obtained by varying the stagnation pressure and temperature in or der to hold dynamic pressure and Reynolds number constant when the Mach number is changed The effects of aeroelastic deformation of mo dels can be studied by va
21. arly made aware of their responsibilities Throughout the design of the buildings the tunnel the control system the data acquisition and data reduction systems ETW has taken security con cerns into account Below is a brief overview addres sing each of these areas 3 2 1 Buildings Figure 10 shows the general layout of the user areas of ETW ETW can provide three clients with com plete privacy at any one time for all aspects of wind tunnel testing and the associated data processing Each user is allocated set of three rooms Model Preparation Room Cart Rigging Bay CRB and a Data Analysis Room In these rooms the client can undertake the model preparation rigging ambient temperature checkout cart installation and data analy sis in complete confidentiality These rooms are for his use only for the full duration of the test Access to these rooms and others in the facility is controlled in agreement with the client by the use of magnetic cards New access codes are given to each test and can be changed on a time basis if required Access to the variable temperature areas of the facility is controlled directly by ETW staff for safety re asons This means that the client needing to work in these areas will be accompanied by at least one mem ber of staff knowledgeable on the systems and proce dures for the cold environment Each of the clients analysis rooms has door to the main tunnel control room
22. ary table is maintained and constantly updated which lists the principle characteristic parameters of a polar However since each quantity of the results data file produced by the reduction program may be included additional summary tables can be created covering a wide band of specific requirements 2 2 2 Data Interpolation and Differencing program performing two parameter interpo lation typically the angle of incidence and the Mach number can be used to evaluate the model characte ristics for required nominal stationary condition e g the Mach number might be interpolated to 4 signifi cant figures e g 0 7500 The degree of the interpo lation polynomial is selectable between 1 linear and 5 however the program switches to lower degree if the specified interval does not contain sufficient mea surement points After interpolation the differences between se veral data sets can be calculated by additional soft ware which has proven to be powerful tool especial ly for the analysis of Twin Sting Rig data It also allows the computation of averages standard deviations and maxima minima Integration of Third Party Test Data Upon request by the client special software can be developed for the conversion of test data origina ting from different source into the format used at ETW thereby allowing the use of ETW owned on line and post processing programmes 5 2 3 Data Prese
23. as high speed systems at pre defined tunnel and model conditions Monitoring of selected signals and triggering of actions if predefined thresholds are ex ceeded e g fast model home in case of high accelerations All acquired data are identified by names that are assigned according to client s specifications Sup porting information e g coordinates in the model or tunnel coordinate system is integrated Instrumenta tion settings e g gain excitation settings are mo nitored and recorded The various signals are available as raw values e g voltage and in engineering units if calibration coeffcients are known This feature has proven to be very useful in all instrumentation and mo del checkout activities The MDA software allows data visualisation in various formats e g tabulated output time charts bar graphs X Y plots in all locations where it is required e g model preparation gt next to the model wind on test gt in the Main Tunnel Control Room As not only raw data are sent and stored at the MDR but also all relevant information required for the interpretation of the acquired data gains calibration coefficients supply voltages etc complete cessing can be performed at any time Operator input such as serial numbers or model configurations can be included in data point for identification purposes This concept ensures that raw data in situ calibra tions and software standa
24. ation changes As significant time can be saved during these handling procedures by avoiding extensive filling and grinding exercises the overall test campaign cost can be mini mized The required surface finish of the models is determined by the client taking into account the test objectives and test envelope ETW is able to provide detailed information to assist in defining the final surface finish for the model As a general guideline a model surface with laminar flow requires a surface finish of less than Ra 0 2 um if tested up to a Rey nolds number of 40 million 4 5 Test Assembly The selection of the final test assembly concer ning the model full span model or half span model and its support system performance balance drag measurement measurement of model components straight sting 2 5 sting 5 sting etc is the client s decision in accordance with the envisaged test objec tives ETW provides the model cart unit the sting sup ports including the sting balances the half model ba lance support system and the instrumentation involved in the test assembly It is therefore necessary to dis cuss all requested equipment and the interfaces in de tail at the start of the test campaign planning process in a kick off meeting An overview of information concerning the available support systems and instrumentation is pro vided in Section 6 ETW 21 22 4 6 Test Preparation Th
25. capabilities the procedures employed and the Services offered It is hoped that this will enable them to assess the tunnel performance against their pro gramme requirements If for any reason these require ments appear not to be met then ETW would be pleas ed to discuss them further ETW 03 2 A U E lt LL O 1 E Europedn bin dtunnel E d i re 4 2 1 ETW Characteristics The ETW facility is a high Reynolds number transonic wind tunnel using nitrogen as the test gas High Reynolds numbers are achieved under the combi ned effects of very low temperatures and moderately high pressures The Mach number ranges from 0 13 for low Speed testing through the range of high subsonic speeds important for the cruising flight of modern transport aircraft up to 1 3 for supersonic aircraft or space vehicle tests in low supersonic conditions E Test section size Mach number range Pressure range Temperature range Max Reynolds number c with c reference length 2 0m x 2 4m 0 13 1 3 115 to 450 kPa 110K to 313K 230 x 10 x 1 m The test section size and the pressure and tem perature ranges represent the best combination of pa rameters to meet the requirement from the aerospace industry to achieve with full span models span about 1 5m a Reynolds number of 50 million at cruise con ditions for large tr
26. ce junctions measuring the temperature of the junctions with a Pt 100 RTD For on board use 10 channel reference junction boxes are available and in each instrumentation cabin a 32 channel reference junction is installed For low level voltage measure ment either Conditioning Units or Analogue Input Units AIU of the PSI system can be used ETW European Transon W 6 2 6 3 Semiconductor Diodes Their high sensitivity 2 5 mV K and their ea se of two copper wire connection make Semicon ductor Diode Temp Sensors an attractive alternative They are excited by 10 uA provided by special current module in patch lead 6 2 7 Model Support Cabling For signal transmission between the Instrumen tation Cabin and the Model Support Sting Boss a large number of different cables are installed in the Model Carts Their length is approximately 30 m It should be realized that the resistance of the cold part of these cables 20 m will decrease considerably compared to ambient temperatures i e will go down from 5 3 Q to about 2 Q for loop of AWG 24 The following cab ling tubing is installed Cross Section Cables Wires AWG Use mm Nr of Nr of Type 60 24 General 0 22 yes 8 7 24 PSI 0 22 yes 8 6 24 T TC 0 22 yes 9 7 16 Power 1 34 yes 6 1 50 Coax 6 Pneum 210 4 00 Tube Table 9 Installed Model Support Cabling APPENDIX 1 Examples of Plot Layouts and Output Styles for Te
27. ch will be pro vided to prospective clients upon request The development work for models suited for ETW s cryogenic environment started as early as 1979 and the first ETW models were built in the period of 1989 to 1994 including very detailed studies of materials fas teners instrumentation coatings handling fabrica tion etc These first models were successfully tested in the early campaigns of ETW and since then vast ex perience has been gained Nowadays model design manufacture and test preparation of cryogenic models entails only slightly more effort than that for conventional models ETW can provide model material forged to the main dimensions of the wings and fuselage in a similar cost range to normal high quality steel The required bolts and screws have been intensively tested and can be provi ded by several companies Model manufacture time is normally in the order of 4 to 6 months depending on the complexity of the model Pre design work is typi cally completed by the client ETW has contacts with model manufacturers who can also provide detailed de sign work During the design period ETW provides ad vice to evaluate critical components and handling techniques In order to optimize model configuration chan ges it is necessary to discuss the individual changes in detail with ETW specialists Spending additional design effort to suppress bolt heads at the model surface sees immediate benefits during the configur
28. d q at each measured section bending esti mate Bending and twist at Half and full models the wing tip or flap track fairing An example of the drag increment repeatability is shown in figure 22 for both low and high Reynolds number conditions These drag increments result from the difference between the measurements of a con figuration with a distorted afterbody sting cavity dummy sting and a configuration with a full afterbody without a dummy sting From these figures it can be seen that the general level of uncertainty attained with the ETSR technique is better than one drag count irrespec tive of Reynolds number and therefore is of a similar order of magnitude as that achieved in the single sting test series 4 4 Model Design and Manufacture Considering the test section dimensions width 2 4m height 2 0m the wing span of transport aircraft configurations should not exceed 1 56m for full models and 1 3m for vertically mounted half models For com Figure 21 Enhanced Twin Sting Rig ETW Furs gm L T E ro alk Figure 22 Drag Increments Measured with the ETSR Technique bat aircraft models the corresponding values are 0 85m and 0 7m respectively The details on model sizing design details materials fasteners and the overall safety procedure is provided in the ETW Model Design Handbook ETW D 95004 Revision A and in the ETW Materials Guide ETW D 95005 whi
29. e size of the system number and type of channels can be adapted to particular test As rule each channel has its own analogue to digital converter and multi plexing is subsequently carried out at digital level The inherent advantage in this methodology is that there is no time skew between individual data chan nels which 15 prerequisite for efficient continuous sweep vs pitch and pause testing When addressed each channel transfers its data to parallel high speed data bus for input into the Model Data Acquisi tion MDA computer 6 2 5 1 Conditioning Unit The backbone of the signal conditioning equip ment in each of the Instrumentation Cabins is formed by 64 Conditioning Units CU performs in one integrated package all of the functions required for conditioning and digitizing the signal of 2 single high accuracy analogue data channel Any number of CUs can be connected to common digital data bus allo wing configurations of computer controlled acquisition systems of arbitrary size The units are completely self supporting inclu de display and can therefore also be used for stand alone applications This feature has proven to be very useful in wind tunnel environment The functions and respective ranges are Excitation Power Supply 0 to 16 V DC Adjustable Zero Offset 200 to 200 Instr Amplifier Gain 1 2 5 1 000 Low Pass Filter Overload Detection Analogue Output Anal
30. e final test preparation of the model and the instrumentation is performed at ETW in one of the Mo del Preparation Rooms The client personnel are sup ported by ETW staff with the mechanical assembly work Model instrumentation is installed by ETW per sonnel An overview of the interfacing components is provided in Section 6 The details need to be discussed with ETW during the client s model design The selection of bolts needs to be discussed with ETW specialists The design details can influence the time for test campaign significantly It is impor tant to optimize the design of bolt heads and the required filling holes in order to save handling time during configuration changes ETW provides filler and sealing materials as listed below Cerrobend is fusible alloy used for larger holes Two component filler materials selected for cryogenic conditions are used for smaller holes Two component epoxies are typical gluing ma terial for transition bands Xantoprene 15 typical sealing material The experience gained with these materials and the individual application methods will be provided to client personnel during training familiarization ses sions with ETW specialists ETW 4 7 Model Handling Procedures ETW is certificated according to the internatio nal quality standard EN ISO 9001 2000 The relevant procedures concerning model handling activities are strictly adhered to during model assembly The follo
31. en ce attention is paid to ensure that thermal gradients inside the balance structure are minimized ETW has adopted the method of running the normal sequence of Mach number test runs with constant recovery tempe rature to keep the balance structure absolutely stable Pressures ETW has a number of PSI pressure scanners of various ranges see Section 6 2 for incorporation into client models These can be used for base pressure me asurements where only a small number of pressures are to be recorded to full pressure plotting models where up to several hundred pressures can be taken It is standard procedure in ETW to test in combined mode i e force moment and pressure measurements acquired simultaneously The PSI units are maintained at a constant tem perature This results in an achievable systems accura cy for the pressure measurements of better than 50 Pa for the maximum range scanners of 30 psi 207 kPa which corresponds to 0 0296 accuracy of full range Temperatures A number of balance temperatures are measured as a standard procedure in ETW to monitor thermal gra dients A similar measurement technique can be used to monitor temperatures in the model assembly if re quired Normally the temperature is measured with Pt100 for general information and global stress ob Servation Any high accuracy measurements require specially calibrated Pt100s which can be provided on request Dynamic Data A High Speed
32. er fuselage diameters For half model testing an external balance is attached to the respective top wall structure of the model cart The layout and load ranges are given in Appendix 3 6 2 1 1 Balance Calibration Facility novel automatic Balance Calibration Machine BCM has been developed and is used for calibrations of all ETW balances The machine is designed to cover the complete temperature range of the facility The BCM is also available for calibrations of clients balan ces It offers the possibility to apply an arbitrary num ber of components simultaneously to calibrate ba lance over realistic multidimensional operating meters Component Nominal Max Normal Force 20 000 N 25 000N 4 0 Side Force 3 000N 3 000N 1 5 Axial Force 1 500 N 2 000 N 0 3 Pitching Moment 1 200 Nm 1 500 Nm 0 4 Nm Yawing Moment 1 000 Nm 1 000 Nm 0 5 Nm Rolling Moment 2 000 Nm 2 000 Nm 1 0 Nm Table 2 Load Ranges and Accuracy of the BCM ETW The load ranges for the different components have been adapted to those of the transport aircraft performance balances and are given in table 2 below The accuracies stated reflect the differences in impor tance of the aerodynamic coefficients 6 2 2 Model Attitude Measurement The precise determination of the drag and lift coefficients in the wind axis system requires that the model angle of attack is known with an accuracy of 0 01 degree Like most other advanced facilit
33. g the parameter names as spe cified in the Output Selection Tables Control informa tion such as processing options additional or modified transducer definition data and model constants is taken from a Constants Set The key element of this concept however is to store all definition data i e transducer excitation voltage calibration coefficients transducer location etc in a block preceding the mea sured values of each polar in the raw data file Since the definition data are read by the reduction program and automatically linked with the measured quantities an excellent integrity and traceability of the test data is obtained Results Data File Flow Wall Corrections Halance Mainces 1 Weng Centre of Ciravity Sing Ooomeiry Dielections Tranter Definition Beis Nadel Corel Data File Del aii h n Dara Flow Keferener System Data Hata ing Device Daia Inzlinomzier 83823 Main Balance Dam Balanced Data Misr Pressure Transducer ata Auteecenckm Transiducer Dain PT IU Thermacoiupte Data Mahipon Pressure Siem 1 18 Figure 24 Data Reduction Schematic Program Flow Reference Systems Rotating Devices Ing Main Palace Secondary Balances Haze Pressure Transducers A Lrimgducers FTI Sensors ples Miahiporn Pressure Sv esns ETW ade Perilea Loads Load Coeffic
34. however only the client whose model is in the tunnel has access to the control room The doors to the other clients rooms are locked and controlled by ETW ETW SSS k 12 Access only accompanied by ETW Tost Team access only accompanied Figure 10 Part of Building Floor Plan 3 2 2 Computer and Data Systems ETW are dedicated to protect all client data from disclosure and misuse and will ensure this protec tion through personnel physical logical and procedu ral measures On the technical side the prime elements of se curity are physical and logical separation of data and access control on a strict need to know basis ETW has three dedicated independent data pro cessing computer systems one for each User Room Client test data are stored on separate and re movable disks or tapes in each User Room which are physically removed from the system and kept in safe custody except for authorized applications For an on going test data acquisition data processing and data display are performed on a separate dedicated network Segment in a restricted area Where network or other data lines leave this restricted area logical filters and network bridges ensure that no access to the system is possible from outside and no client data are transmit ted on such lines Where patching of network intercon nections is possible the patching is as transparent as possible and is subjec
35. iciency in terms of cost and duration Principally a test campaign will be covered by a contract signed by ETW and the client A contract ba sically consists of a Contract Agreement and several Annexes the Contract Agreement signed by both par ties defines the parties the ETW contract number the scope of work the remuneration and payment terms the time schedule and all annexes forming an integral part of the Con tract the different Annexes detail the General Conditions of Contract applic able to all contracts with ETW for test cam paigns the Special Conditions of Contract applic able specifically to this contract the test programme as agreed between ETW and the client the test time schedule Any change to the test programme having an impact on price or time schedule is subject to the Contract Change Procedure in accordance with the Con tract Conditions If the relation between the client and ETW is al ready well established test campaigns can also be go verned by a purchase order of the client based on an ETW quotation for the respective testing programme 3 2 Security and Client Confidentiality An important aspect to every client is the secu rity of his test how safe from prying eyes is the mo del the test programme the test results etc The entire staff assigned by ETW to a client test are ETW employees All ETW employees have signed confidentiality agreements and are regul
36. ients Hase I Cavity Presu LI poacandh Bueyaney Secondary Balances Results Physical Units Temperatures Pressure Coefficient Local Mach amber Pressure Harr Local Lift Pechang Moment IPS Input Selection Table OFS Output Selection Table 27 28 5 2 1 1 Computation of Flow Parameters The flow parameters are computed from the data of two Flow Reference Systems FRS using the tempe rature information plus the measured pressures Each FRS contains two absolute and two differential pres sure sensors of different ranges and accuracies The data reduction program uses the values of the two most accurate transducers available for the pressure level being measured For special purposes an option exists to define the data of certain other pressure or temperature trans ducers as reference values 5 2 1 2 Determination of the Model Position In the case of single and twin sting mounted models the reference incidence angle is usually mea sured by an internal inclinometer whereas the roll an gle information is supplied by a resolver in the sting boss In addition the incidence angle of single sting models is calculated from model support data sting geometry data and deflections under load If the enhanced twin sting rig is used the in formation of two further inclinometers installed close to each boom balance is required to determine the ba lance positions and transform the balance
37. ies ETW relies on a classical gravity vector sensing servo accel eromet er ETW equips each model with a Sundstrand Q Flex inclinometer mounted in a vacuum insulated heated box Several versions of the heated box are available larger one contains Q Flex two electro lytic bubbles model erect and inverted and a tri axi al accelerometer The latter can be used for model vibration monitoring and also for centrifugal accelera tion compensation The mounting base is made of low expansion carbon fibre material to avoid distortions due to temperature gradients The small heated box intended mainly for fighter model applications does not have the electrolytic bubbles special Inclinometer Conditioning Unit 100 directly computes the angle in thousands of a degree Amplification filtering and analogue to digital conver sion are adapted to the wind tunnel environment Spe cial circuitry allows a partial compensation of centrifu gal acceleration errors using Z and Y axis accelero meters as inputs Each MDA system includes four ICUs to enable conditioning of Q Flex inclinometers that are installed in other locations i e the sector and top wall Accuracy Resolution 0 40 N 0 15 0 03 N 0 04 Nm 0 05 Nm 0 10 Nm 6 2 3 Multi Port Pressure Systems For multiple pressure measurements ETW has standardized on the PSI 8400 series of systems to tal of five systems are available which are allocated as follows
38. images are taken just prior to and dur ing rapid temperature step in the flow Since the heat transfer rates are different for laminar and turbulent boundary layers the temperatures seen by the IR ca mera system in the transient temperature range differ in the laminar and turbulent flow regions of the wing Using the first images before any temperature change as reference the two areas can be clearly distinguis ETW hed A temperature step of about 10 K is required to achieve images with sufficient contrast the ETW flow control can impose this step in a matter of seconds well before the temperature gradient in the wing struc ture can equalize Fe 10 x 10 5 M 20 75 T 1298 Figure 17 Infrared Image of Typical Transport Aircraft Wing An example of processed image taken of the ETW Reference Model at 120K is provided in figure 17 Images taken over the complete Reynolds number range show the development of the boundary layer over wide range of test conditions At the highest Reynolds num bers the images prove that transition from laminar to turbulent is either at or very close to the wing leading edge At the intermediate Reynolds number shown in figure 17 areas of laminar flow are still clearly visible in the picture taken by the cryogenic camera system This confirms both the functioning of the test techni que and also the flow quality at ETW A side aspect of IR testing is that the applied
39. ined in the best conventional transonic wind tunnels and in some ways better being consis tent with high Reynolds number testing The flow quality requirements are applicable in the model test volume i e over test section domain centred on the sting mounted model centre of rotation with length of 2 4 m and cross section extending to within 2 boundary layer thicknesses from the walls The Mach number spatial uniformity shows maximum deviation of 0 001 in subsonic conditions and 0 008 in supersonic conditions within the test volume These deviations are applicable for an empty test section and are to be seen as 36 values i e virtu ally peak to peak values Thermal distortions after temperature change are within tolerance 2 5 minutes after 40 K change at 3 K sec or 5 minutes after inserting model cart in the tunnel or 30 minutes after full range tunnel cooldown at 80 K hour The control system is designed to maintain the time variations of the Mach number during polar be low 0 001 over the full M range It has set point change capability resolution of 0 001 in Mach num ber It is also designed to prevent the relative time variations of the total pressure in the tunnel from ex ceeding 0 2 i e APt Pt lt 0 002 during a polar The temperature set point during polar 15 kept to within 0 5 K This corresponds to the specified temperature uniformity within the test volume The above cap
40. ist of Half Model Wing Tip determined with pressure Com parison Method and Luminescent Marker Imaging Method ETW 19 20 The main features are Method Model Requirements Deflection Information Applicability MDMS Model Deforma tion Measurement System Non shiny surface Wing pressure compari 6 8 pressure taps per son wing section Inserts with luminescent paint in the wing tip or flap track fairing Luminescent marker imaging In addition a videogrammetric technique using paint targets on the wing is under development to pro vide an alternative to the luminescent marker imaging method for half models with only sparse or no pressu re plotting Sting Interference Measurement ETW owns a Twin Sting Rig TSR and can offer it with two different measurement techniques from which sting interference effects on lift drag and pit ching moment may be derived and subsequently app lied to the corresponding single sting database The first method is the standard twin sting technique which derives sting corrections from the net measurements on a split rear fuselage The second method is the Enhanced twin sting rig ETSR technique which derives sting corrections from the net measurements on the complete model by using twin six component balances figure 21 Bending and twist insi Full models de an area field of view of the camera Twist as function of C Full and half models an
41. lars Rapid generation of complex plots through use of control files Data point selection according to an arbitrary selection criterion Staggering option Automatic identification of available printers Mathematical operations on and between se lected quantities including curve fits Some examples of plot layouts and output sty les are given in Appendix 1 ETW 29 wawa 5 3 AS 1581 ned 6 1 Model Supports 6 1 1 Model Carts Model Cart 1 Model Cart 2 Distance from Point mm 2 296 3 097 of Model Rotation to Model Cart Flange Pitch Range 10 to 35 10 to 20 Roll Range 190 190 Pitch Rate s 0 05 102 0 05 to 2 Roll Rate 975 0 05 to 10 0 05 to 10 Table 1 Characteristics of the Model Carts To meet the productivity and confidentiality de mands of the aerospace industry ETW is designed to operate an interchangeable model cart system Two model carts are available for sting mounted full span models one of which can be modified to accept verti mounted half models cart with sting moun ted model is shown in figure 25 6 1 2 Half Model Facility A half model testing capability is provided by an exchange of the slotted test section top wall of Model Cart 1 with a solid half model top wall including turntable and an external five component balance Pitch range Pitch rate 45 degrees 0 05 to 1 degree sec A typical half model attached to
42. lift induced up wash Switching between productive and survey data acquisition mode e g pitch pause polars Movement of the model to safe position after the end of 2 polar or when required by model loads or dynamics Communication with and scheduling of other wise independent systems like cameras high speed acquisition and model deformation measurement systems Supply of identification data e g Polar Da tapoint Number Mach total pressure Triggering on selected model and tunnel con ditions Suspension of model movement while these systems are collecting data Other test specific data systems can be integra ted in similar way but need adequate preparation ti me depending on the requested communication proto col currently preferred RS232 5 2 Data Processing data reduction computer running under the operating system OpenVMS is located in each of the User Rooms It is dedicated to the client throughout the campaign and performs data storage and data pro cessing The data are exclusively stored on an external disk which can be dismounted and stored under the control of the client cartridge tape drive is also at tached so that backup of the test data and safeguar ding of the tapes are performed locally The client has direct access to the data reduc tion computer from his User Room Immediately after the end of each polar preliminary test results are alre ady accessible through
43. ll signal data di rectly as measured Higher frequency data can be hand led using analogue RMS converters for real time purpo Ses e g accelerometers Another option are MDA con trolled data captures with the High Speed Dynamic Data Acquisition System HSDAS uer DEDICATED COMPUTERS FOR DATA REDUCTION 18 User Rooms Processed Data COMMON WORKSTATIONS ws AND PRINTERS in MTCR ETW 25 wasa 26 In more detail the MDA software performs the following tasks Integrates all model related instrumentation and control systems i e General purpose signal conditioning equip ment DAS CU RMS see 6 2 1 Flow Reference Systems FRS see 6 2 4 Multiport Pressure Systems MPS see 6 2 5 Controllers for heated boxes Controls and monitors the model position Integrates special acquisition systems like ca meras and high speed dynamic data sytems Groups the data of one data point into records and transfers them to the dedicated Model Data Reduction MDR system for data storage Makes all data accessible to the operator in real time see below quick look display Additional tasks during wind on testing are Communication with Windtunnel Main Control WMC and monitoring of tunnel conditions Synchronization of data acquisition and model positioning to tunnel conditions including the start termination of polars Triggering of special acquisition systems mer
44. loads into the model coordinate system The incidence angle of half models is derived from the measured angle of the turntable together with the calculated deflections of the balance under load 5 2 1 3 Computation of Model Loads The signal offsets of the balance are computed from wind off data by the known balan ce loads with the calibration matrix of a given balance temperature After subtraction of the offsets from the balance signals the gross loads are calculated using the relevant balance matrix From the balance gross loads the model weight components are subtracted to obtain the aerodynamic loads and coefficients which are transformed into various coordinate systems and subsequently corrected for base cavity pressure buoy ancy and wall interference effects ETW 5 2 1 4 Processing of Autonomous Transducers The processing of temperature sensitive abso lute or differential autonomous transducers resistance temperature sensors Pt100 type and thermocouples is also a standard feature of the data reduction program 5 2 1 3 Processing of Pressure Transducers For the transducers of all Multiport Pressure Systems the pressure coefficients local Mach numbers and pressure ratios are calculated per data point pres sure coefficients are optionally averaged for each data point of pitch pause polars In the case of pressure plotted models with sufficient number of chord wise taps the pre
45. mass flow of gaseous nitrogen is exhausted upstream of the stilling chamber The overall layout of the circuit and especially the stilling chamber area nozzle and test section are consistent with the high flow quality required for high Reynolds number testing The test section is equipped with the capabili ty of having all four walls individually closed or slotted figure 4 F Figure 4 Aircraft Model in the ETW Test Section ETW European Transonic Windtunnel User Guide Test section details Dimensions HxWxL 2 00m x 2 40 mx 9 00m incl re entry Wall Configuration Top and bottom walls 6 slots each with 6 25 porosity wall angle remotely adjustable Side walls 4 slots each with 7 4 porosity Re entry area provided by movable finger flaps one per slot Optical access provided in all walls For full model testing the standard test section configuration has slotted top and bottom walls with an overall effective porosity of 3 4 For high speed half model testing the standard test section configuration has slotted side walls with an overall porosity of 4 6 Downstream of the test section is the adjust able second throat which serves to minimize flow dis turbance propagating upstream and to provide Mach number control during tunnel operations The second throat is normally used for 0 65 lt M gt 1 0 operation 2 3 Flow Quality ETW has a flow quality at least as good as the quality obta
46. n significant differences between wind tunnel tests and real flight often leading to costly de sign changes after the first flights of a new aircraft Nowadays with the availability of advanced CFD me thods some Reynolds number effects are better under stood but so called indirect Reynolds number effects are still difficult to predict Flight performance testing with buffet onset investigations and drag reduction on attached components etc are typical objectives focussed on high Reynolds number testing Striving for a capability to analyse such effects by experimental investigations on a wind tunnel mo del obvious requirements are a wide Reynolds number range ideally up to flight conditions the independent variation of tunnel parame ters to separate between aerodynamic and model deformation effects the extraordinary quality of steady and dyna mic flow to generate conditions comparable to flight based on a high level of tunnel set point stability and repeatability the tools and techniques to measure and visu alize aerodynamic effects close to the surface of the aircraft model the instrumentation for measurement of speci fic test assembly characteristics like wing de formation sting interference model dynamics The test objectives listed above influence the model design in the early stage of the project Design inputs will be provided by ETW concerning the tunnel test envelope the installed instr
47. ntation Test data can be presented in numerical or gra phical form The respective programs use largely identical command syntax and are at the client s dis posal However if the client prefers to use his own analysis and presentation software the data can be transferred to his computer shortly after the test run In addition to some special data formats e g TecPlot a simple ASCII format compatible with most spreads heet programs 15 offered as standard option Howe ver flexibility of data arrangement and format also al lows an easy adaptation to individual requirements 3 2 3 1 Numerical Presentation The program for producing tabulated output allows the definition of an individual format for each quantity a quantity header different from the quantity name and a unit denomination The page layout num ber of rows and columns is adaptable to any paper format 5 2 3 2 Graphical Presentation The graphics tool available at ETW can be used for real time data display and off line plotting The main features are Presentation of purely dynamic data e g vs or combined static and dynamic data e g distribution vs tap location Flexibility in combining data from different polars and data files including raw data interpolated data and results obtained from differencing Legend information derived directly from the data file Variable plot layout Quick and easy access to reference po
48. odel Data Acquisition MDMS Model Deformation Measurement System MDR MHC MPS MTCR PSI PSP PSU QA RMS RTD SJU TCR TPS TSP TSR VMS WMC Model Data Reduction Model Handling Control Multiport Pressure System Main Tunnel Control Room Pressure Systems Inc Pressure Sensitive Paint Pressure Sensing Unit Quality Assurance Quick Change Room Root Mean Square Resistance Thermometry Device Scanner J unction Unit Temperature Conditioning Room Turbine Powered Simulation Temperature Sensitive Paint Twin Sting Rig Virtual Memory System Variable Temperature Checkout Room Windtunnel Main Control Published by European Transonic Windtunnel ETW GmbH K ln Editor Georg S tsch Pictures ETW EADS Airbus Dassault Layout and Design by ziller design M lheim an der Ruhr Germany Printed by Thierbach GmbH M lheim an der Ruhr Germany European Transonic Windtunnel Ernst Mach Strasse 51147 Cologne Germany info etw de www etw de
49. odel testing Reynolds numbers based on the mean aerodynamic wing chord of up to 53x10 can be achieved and 80x10 with semi span models The details on model sizing criteria are provided in the ETW Model Design Handbook ETW D 95004 Re vision A Pure Reynolds Number Effects By establishing the test programme the maxi mum requested Reynolds number is the most important parameter However by determining Reynolds number range the temperature and pressure levels have to be carefully selected and the overall strategy to control model deformation effects has to be clarified ETW pro vides the ability to separate pure Reynolds number ef fects from model deformation effects by independent control of velocity temperature and pressure typical test programme normally includes several levels of con stant dynamic pressure q as indicated in figure 11 for analysing pure Reynolds number effects Due to slight variation in the model s elasticity modulus E with temperature ETW has adopted the method of using constant value of Figure 11 Operating Envelope for q E testing Model Deformation Effects Repeating polars at constant Reynolds number at different dynamic pressure levels provides the opportunity to investigate pure model deformation effects Both Reynolds number and model deformation effects as shown in figures 12 and 13 also affect the measured forces and moments The pitching moment characteris
50. ogue to Digital Converter Numerical Display of ADC Floating Input up to ADC Table 4 Conditioning Unit Ranges Peak amp Average 15 bits 16 bits opt Opto isolators ETW Wide band amp Filtered Two compatible versions of ADC plug in cards are available The slow model is a dual slope integra tion type allowing 20 Hz sampling rate whilst the fast model is a successive approximation type with a con version rate of 20 kHz Since these are the sampling ra tes per channel the aggregate rate for a large number of channels can be very high All manual switching functions can be read out as status data and the cali bration or check out functions can also be remotely ac tivated 6 2 5 2 Calibration Generator The Conditioning Units have relays for swit ching externally generated calibration voltages to the inputs of the Amplifier and the ADC allowing com plete computer controlled calibration to be carried out A high precision high stability Calibration Generator is included in the system for generating the appropriate voltages This has separate CAL ADC and CAL AMP out puts the ratio of which set by high accuracy volta ge divider represents the nominal gain of the amplifier to be calibrated The voltage reference source 15 tem perature controlled and has extremely good long term stability The Calibration Generators are crucial for the accuracy and traceability of the results of the data system They are reg
51. paint can influence the aerodynamic data The expe rience for transport aircraft models so far is that drag is typically increased by 2 drag counts but lift charac teristics are not affected In preparation for the use of Pressure Sensitive Paint PSP ETW is already able to apply Temperature Sensitive Paint TSP as an alternative to infrared ther mography Validation tests were carried out on the ETW reference model using new type of TSP which 15 ticularly sensitive at cryogenic temperatures The non toxic paint is applied to the model wing surfaces in exactly the same way as other coatings that are used e g for visual or infrared imaging It is then polished to a high quality surface finish For image acquisition the paint is stimulated by flashes of high power ultra violet light This energy in turn causes the TSP to emit red light with temperature dependent intensity calibration is performed beforehand to quantify the relationship between intensity and temperature The paint used in ETW exposes a linear sensitivity over the temperature range of 110 K to 170 K measurement grade CCD camera is utilized to acquire the raw data images typical exposure time being 1 second Some post processing of the images is subsequently perfor med to remove background light by means of subtrac ting reference images At the end of this process the temperature distribution over the entire illuminated and acquired model su
52. perties of various instrumentations used with models at ETW Technical descriptions and lists of available compo nents together with interface information are given in Section 6 Model Incidence Model incidence is a fundamental measurement quantity normally measured at ETW with high precision Sundstrand inclinometers installed within a thermally controlled package A resolution of 0 001 is achieved with the standard equipment and the estimated abso lute accuracy for incidence measurement is around 0 005 Special care is given to the installation of the model inclinometer box in order to minimize any thermal stresses and deformations being introduced in to the model fuselage Any deformation would create errors of the model incidence Forces and Moments Model forces and moments are generally measu red with a strain gauge balance Full span models in ETW are normally mounted directly on to the balance which is internal to the model The balance in this ca se measures six components normal force side force axial force pitching moment yawing moment and rol ling moment Semi span or half models are mounted on a fi ve component balance which is external to the model and is situated in the top wall of the test section The resolution of axial force normal force and pitching moment is in the order of 0 01 of the full range capacity The accuracy achieved is specified as 0 1 for the standard balances In the testing sequ
53. polars together with pitch and pause polar In general the repeatability in drag is around 1 drag count irrespective of the traverse type and test temperature Equally important is the level of repeatability of the measurement of pressures From fi gure 14 it can also be seen that the agreement bet ween the pitch amp pause and continuous traverses 15 maintained throughout the entire incidence range pri marily due to the selection of reduced traverse rate at incidences above buffet onset E Fa e TI r u 1 a 5 w nn kE EL snr Figure 14 Repeatability of Test Data In addition an absolutely perfect long term peatability of test conditions is ensured regardless of the time between tests 4 2 Measurement Capabilities A brief overview of the standard techniques that can be employed at ETW is given below however this list should not be considered as comprehensive For other types of tests or measurement techniques ETW further information will be provided by ETW in response to specific requests Testing can be conducted either in the pitch pause mode or the continuous traverse mode The continuous traverse rate depends on the amount of measurements and the test objective Typi cal values of up to 0 25 s are used In buffet onset region the rate is reduced to 0 15 s or even lower This section summarizes the general pro
54. rds are fully traceable in time and version ETW Another important function of the MDA software is the incidence and roll angle control of the model support mechanism During model preparation and che ckout the commands to position the model are manu ally entered by the operator For wind on tests the complete sequence of tunnel conditions and model tra verses is prepared offline as polar control program which is subsequently automatically executed and per forms all data acquisition and model control functions for complete run Model movements of the following types can be defined in polar control program Continuous incidence traverses with select able pitch speed typical 0 25 5 for pure force measurements 0 1 to 0 15 s if com bined with pressure measurements Pitch pause incidence traverses with select able step size and acquisition interval typi cal pitch speed 0 3 s pause duration two to five seconds Side slip traverses in pitch pause mode re quires combined sector pitch and roll move ments Roll traverses to change from fin up to fin down position Automatic execution during wind on includes the following actions Waiting for the requested tunnel conditions to become steady Mach total pressure and tem perature Positioning of the model at the requested start position Control of the model traverse including pre diction and compensation for sting bending and
55. rface can be quantified figure 18 Figure 18 Visualization of Boundary Layer Details by Temperature Sen sitive Paint Flow visualization To monitor and to document specific flow beha viour matrix of minitufts suitable for the cryogenic environment can be attached to the model surface and used throughout the complete test envelope For low speed testing for example each tuft is individually attached with a thin Kapton tape to provide sufficient stability at highly unsteady flow conditions Figure 19 compares images taken at two different Reynolds num bers at identical Mach number and angle of incidence of the model Figure 19 Flow Details Indicated by Minitufts Far field flow observation with Laser techniques is in development For example wake flow develop ment can be measured with this technique Seeding of the flow is achieved with water vapour at such a low level that the model is not affected in any case Model Deformation Measurement ETW is currently offering its clients three inde pendent methods to determine the wing deflection of a wind tunnel model see figure 20 er 8558 biahe i ami Rai ia He TR B T ON LEER k mq wawa Pana re kaa ms 1 bet A a 08 uar Figure 20 Above Wing twist of a full Modell determined with MDMS and Pressu re Comparison Method Below Tw
56. rt that clients generally require from industrial wind tunnels Model data acquisition is performed close to the model in the instrumentation cabin which remains with the model cart The acquisition system comprises large number of transducers for forces pres sures temperatures attitudes positions etc both in the model and inside and around the wind tunnel the related sensor conditioning amplification and analogue to digital conversion in the data acquisition systems dedicated data acquisition computer Signal conditioning and analogue to digital conversion ADC feature great flexibility and high re solution for dealing with different types of sensors and signals ETW 09 ILNANWADVNVNW NODIV4HINVID 15 41 3 1 Initial Contacts Testing Contract Enquiries by the prospective client requesting further information regarding a possible test entry should be made to the ETW Managing Director After preliminary discussions defining the test requirement and schedule an ETW test engineer will be nominated to be the point of contact throughout the test ending with the final test report The test engineer will co or dinate all personnel and services to ensure a prompt response from ETW to all queries related to the tests This test engineer will work with the client to optimi se the test sequence taking into account the facility characteristics to provide eff
57. rying the dynamic pressure whilst holding the Mach number and Reynolds number constant as indicated by the trajectory line indicated in the envelope of figure 2 Testing in ETW can also be carried out at am bient temperature as in conventional wind tunnels whilst the mentioned special features of ETW remain valid This has the extra advantage of being able to provide the continuity of data from cryogenic to am bient conditions high to low Reynolds numbers and to compare results against tests in other conventional tunnels with the same model In addition ETW offers absolutely stable and accurately repeatable test conditions over the full tem perature range from cryogenic to ambient regardless of the time between tests ETW 05 OG 2 2 Aerodynamic Circuit Figure 3 Aerodynamic Circuit ETW has closed aerodynamic circuit figure 3 contained inside an internally insulated pressure shell This pressure shell and all internal structures are made of stainless steel which does not embrittle in the cold nitrogen environment The compressor with maxi mum drive power of 50 MW circulates the nitrogen gas around the circuit To achieve and maintain the desired low temperature of the test gas liquid nitrogen is con tinuously injected into the tunnel upstream of the compressor where it immediately vaporizes forming the cold wind tunnel gas In order to maintain the de sired pressure a corresponding
58. s of the services to be provided and the level of ETW staff participation need to be ad dressed client may for reasons of model complexity or confidentiality select to undertake the model pre paration rigging and data analysis unaided by ETW staff In this scenario ETW would enter discussions with the client to determine the model and data quali ty control and assurance procedures This would cover aspects related to model integrity strength inspection procedures and data accuracy and repeatability cove ring model and tunnel performance Whilst many aspects of the services provided by ETW do not differ from the common practice in present large conventional wind tunnels the key elements re lated to high Reynolds number testing and productivi ty are unique to ETW Included in these services are the following Provision of the Model Design Handbook which outlines the criteria for the design construc tion analysis quality assurance of test as semblies and components for testing in ETW Advice on model design instrumentation and test techniques many of which are specific to ETW Evaluation of client test programmes to opti mize the test objectives with cost effective ness of operation and to determine the Scope of data processing Estimate of test duration and cost of client programmes Testing of the client s model and the supply of test results ETW can also provide if required services to under
59. ssure taps In order to assure sufficient accuracy and resolution of M and q over the full operating envelope of ETW three pressure ranges for Pt Ps are necessary Each FRS the refore contains four high accuracy pressure transdu cers two absolute ones for Pt and Ps and two diffe rential ones for Pt Ps For measuring total tempera ture Tt a very accurate temperature sensor channel is included Accuracy and resolution details are listed in table 3 Parameter Range Accuracy Resolution Unit Pt 100 500 050 010 kPaAbs Ps 50 500 0 010 kPaAbs Pt Ps1 0 140 15 002 kPaDiff Pt Ps 2 0 40 005 001 kPaDiff Tt 80 313 0 010 K Table 3 Flow Reference System Capability The FRS is an adapted version of the 8400 SP mainframe supplied by Pressure Systems Inc PSI The main modifications are Addition of board for temperature measurement Addition of second IEEE 488 interface Software enhancements The system uses high accuracy Paroscientific Di giquartz transducers in the four Pressure Sensing Units PSU s ETW 33 34 6 2 5 Signal Conditioning Equipment The general purpose signal conditioning equip ment is intended for use with passive instrumentation Such as balances individual pressure transducers RTDs and thermocouples Requirements are different for eve ry test 50 large flexibility in every aspect 15 essenti al ETW opted for modular approach where even th
60. ssures of each evaluated wing section can be integrated for an assessment of the local normal force lift and pitching moment coefficients hydrostatic effect correction as well as an off set sensitivity correction can be individually applied to each pressure transducer irrespective of its type The consideration of test section pressure gradients accor ding to the stream wise position of the respective pres sure tap 15 also possible 5 2 1 6 Corrections ETW has worked out an extensive set of correc tions covering all types of models and model sting combinations The residual pressure gradient in the empty test section plus the pressure gradient due to the presence of a certain sting affect the static pressure at the model reference cen tre used to derive the reference Mach number all pressures measured on and inside the model including base cavity and split plane pres sures the model drag due to buoyancy Wall interference corrections cover model blockage angle of attack pitching moment wall induced buoyancy drag The flow angularity and curvature are deter mined and repeatedly checked in the course of each test cavity pressures are normally measured by dedicated transducers fully synchronized with the balance signals The resulting correc tions are applied to the computed model loads 5 2 2 Post Processing 5 221 Test Summary Tables For each test campaign a summ
61. st Results APPENDIX 2 Model Support Components Stings etc APPENDIX 3 Overview of ETW Balances APPENDIX 4 List of Abbreviations x 2 n n 4 European Transonic Windtunnel User Guide fi Test Campmgn TE 906 LUnspecihern Kia Test 2 351 359 358 2012 Labels chu Mach Rel Pi L Tras D Td 129 151 71 3 40 D 2 FREE Ge 120 1485 1 2 FREE 5 9 120 144 1 121 5 420 FREE 1 Pee gt Mach Pi 3 407 FHEE 3420 0 2 2 2 FREE 1 43 150 3 27 120 1455 121 0808 120 1441 12065 430 2 FREE On i APPENDIX 1 38 ETW European Transonic Windtunne User Guide m a ND Ef Test Campaign Unspecified Model Test 4 Polar 175 0 02 04 06 08 1 12 14 15 18 2 22 24 Labels Polar M Rec Pt Tt Alpha Hes abs bia Syy2a 5 Cp SW3 1 4 4 4 1 1 1 1 1 4 4 4 1 4 4 1 i 4 i 4 1 N 1 i T 4 4 1 1 N 4 1 1
62. t of the network relevant for the MDA function Much attention has been paid to data security and confidentiality The access control mechanism Figure 23 Model Data Aquisition Network Schematic passwords etc of the VMS operating system is fully ex ploited Data disks and tapes can be removed and sto red in a safe and opto fibres are used for sensitive links to reduce the risk of tapping If necessary all computers including the MDA can be physically disengaged from the network and operated in stand alone mode An important criterion for each run of the wind tunnel is productivity so that data rates and quality and integrity must meet the highest practical standards to mi nimize the cost per polar This implies for the MDA that computers are controlling all activities during a wind on test e g start stop of model traverses change of tunnel conditions camera acquisition and dynamic data capture allowing the operator to fully concentrate on the monitoring of the test progress and to respond to critical situations Acquisition rates can vary from 0 01 Hz survey mode at night to 20 Hz the latter being used for spe cial investigations Typical data rates for productive wind on polars are 5 Hz for autonomous transducers and balances and 1 Hz for Multiport Pressure Systems The analogue filters in the instrumentation amplifiers are usually set to 1 Hz they are superior to any numerical averaging The MDA therefore stores a
63. t to inspection by client s and Security staff Connections are mainly by fibre optic cables to avoid interception through radiation ETW 5 Card BAC door Cillamt E TW doar The Virtual Memory System VMS operating Systems security is used to authenticate users and to restrict access to all computers For critical cases complete physical separation and electromagnetic shielding of the data processing system is possible All ETW personnel are kept aware of security re quirements and are contractually obligated to security and confidentiality 3 3 Quality Assurance ETW has appointed a Safety Security Officer and a Quality Engineer responsible directly to the Mana ging Director for all aspects related to quality assu rance and control of the facility equipment personnel and results ETW is certificated according to the inter national quality standard EN 150 9001 2000 As part of a regular product assurance program me all components associated with the generation of test data the actual tunnel its instrumentation and data systems etc are periodically checked by the ETW team In addition repeatability tests with calibration probes and reference models are regularly carried out to confirm that the high degree of quality is maintai ned throughout the years 3 4 Provision of Services At an early stage in the discussions on the test programme the detail
64. take or assist in model preparation model rigging and configuration changes Software development data analysis instrumentation calibration ETW also has available small machine shop where running repairs or modifications to equipment can be made either by ETW staff or by qualified client personnel The following test equipment is offered for use at ETW see detailed description in section 6 model supports internal strain gauge balances full models half model balance model instrumentation balance calibration facilities engine simulation future 315 Survey of Testing Operations Many client related activities are taking place in ETW simultaneously Some of them during the pre and post test phases involve test engineers design office staff instrumentation specialists and software specia lists for relatively long periods Several other activities require intensive mechanical and experimental work on models at different stages of the test campaign Other activities are of a short duration on an ad hoc basis For one typical test campaign the schedule could be 3to 12 months for test preparation generally undertaken out of ETW premises This may in clude model fabrication 5 to 15 days for model equipment integration normally undertaken in an ETW Model Prepa ration Room 1 or 2 days a Cart Rigging Bay CRB for model mounting calibration and checking on a cart
65. the model cart is shown in figure 26 Figure 25 Model on Straight Sting in Test Section Figure 26 Half Model in High Lift Configuration Feasibility studies and preliminary tests have been conducted for high pressure gas supply system to enable in the future Turbine Powered Simulation TPS with half models 6 1 3 Stings ETW owns collection of different sting sup ports with various design concepts and joints Straight stings for 0 and 2 5 attachment Z sting and fin sting components twin sting support and several adapter pieces are available as summarized in Appen dix 2 A sting geometry with low interference has been ETW 31 maw 32 developed with special attention to sting divergence During model design the bending of the balance and sting is critical to the required gap between the model fuselage and sting Detailed computation and careful selection of the tunnel test envelope is therefore ne cessary for an optimized model design Individual adaptation or special design and ma nufacture of particular supports and stings for clients models is possible in co operation with ETW 6 2 Instrumentation 6 2 1 Balances The ETW balances are listed in Appendix 3 giv ing details on dimensions and loads Different joints are available The standard ETW internal performance balance has a flange with 100 mm outer diameter Taper joints are also available to allow installation in small
66. tics show the most dramatic variations with both Reynolds number and aeroelastic effects clearly visible nere amar D D uL PM sassa T Figure 12 Pure Reynolds Number and Pure Model Deformation Effects on Pitching Moment Figure 13 Aeroelastic Effects on Lift Curve Slope The aeroelastic effects are also clearly evident in the lift curve slope characteristics whilst the associ ated Reynolds number effects are seen to be much smaller in comparison From this review it 15 clear that extreme caution needs to be exercised when attemp ting to obtain true scale effects from wind tunnel test data The ability to independently vary Reynolds num ber and dynamic pressure provides ETW s users with a distinct advantage in understanding scale effects How ever it is only by combining these capabilities with well designed model and an appropriate test program me that real gains in understanding can be achieved Although the issue of quantifying the actual model de formation at particular test condition remains dif ficult area ETW offers three methods of determining the model deformation as outlined in Section 4 3 ETW 15 w 16 Repeatability small number of repeat conditions are mally built into each test programme to confirm data quality typical example of the short term repeata bility is provided in figure 14 which includes two continuous traverse
67. tiveness of this interface are shown in figure 15 After having gained experience from several test campaigns stronger actuator located in the sting and operated jointly with the active interface has been developed This Anti Vibration System AVS enables single sting supported models to be tested in to the buffet region EE I Figure 15 Effectiveness of the Anti Vibration Interface ETW 7 w 15 4 3 Complementary Testing Techniques Transition detection In addition to obtaining forces moments and pressures data ETW provides different techniques for surface flow visualization ETW operates two infrared camera systems one with thermally controlled stan dard camera units for ambient temperature to 220 K and one for cryogenic conditions covering 220 K to 110 K The model requires coating of 0 1 mm thik kness to be applied to the surfaces with the exception of the wing leading edges first 3 of wing chord and the pressure plotting rows photograph of the leading edge region is shown in figure 16 Figure 16 Wing Surface Coating for the Acquisition of Infrared I mages In the region of the leading edges and at each of the pressure plotting stations the target is to achieve smooth transition between the coating and the metallic surface and to keep the overall surface rough ness to less than Ra 0 2mm For the specific task of boundary layer transi tion detection
68. ularly calibrated by an accredited laboratory CAL ADC output 11 000 to 11 000 V Accuracy CAL ADC 002 Resolution 1 000 V Offset 10 V 0 10 V Vernier manual 0 to 1 000 V CAL AMP voltage divider 1 2 5 10 to 5000 Accuracy voltage divider 01 Table 5 Calibration Generator Specification 1 3 10 1 000 Hz Wide Band Buffered 16 384 to 416 383 mV 6 2 5 3 Multi Channel Conditioning Unit For those applications where the primary inte address decoding into individual strobe signals BCD to binary encoding when necessary command decoding e g for calibration purposes handshaking with the MDA computer opto isolation of the computer 10 signals rest is in the component of dynamic signals e g ac celerometers acoustic transducers Kulites or buffet gauges special Multi Channel Conditioning Unit MCCU is included In compact 19 rack it provides timing for high speed data acquisition 6 2 5 6 all essential functions for 16 channels Excitation Power Supply 0 to 15 V DC Adjustable Zero Offset 100 to 100 mV High pass Filters 1 Hz Separate amp DC Gains 1 2 4 8000 Bandwidth 100 kHz Line Drive Capability 10 nF DC Read out amp Display 16384 to 16383 mV Low Noise level 3 uV rms Wideband Remotely programmable EEE 488 Table 6 Multi Channel Conditioning Unit Data The overall accuracy is 0 196 6 2 5 4 Multi Channel RMS Converter For
69. umentation with rele vant interfaces and the possible use of different test techniques A typical example is the maximum achiev able dynamic pressure which is not only the basis for all model stress computations but also determines de formation dependent design details Detailed discussions between the client and ETW specialists are therefore essential during the early Stages of a test project 1 3 Organisation The organisation and staffing of the company is designed to allow ETW to operate efficiently whilst pro viding clients with all necessary services in relation to wind tunnel testing The complement of ETW staff includes expe rienced test engineers and aerodynamicists experts in the fields of design data processing and test instru mentation and skilled technicians for model rigging wind tunnel operation and workshop tasks together with the necessary safety security and administrative functions The official language of ETW is English how ever communication is also possible in both French and German ETW GmbH holds a certificate according to EN ISO 9001 2000 issued on behalf of the accreditation bodies of the four participating nations by Lloyd s Register Quality Assurance Ltd following a thorough assessment and regular audits of the quality manage ment system 1 4 Purpose of the Guide The purpose of this guide is to give prospective users of ETW an introduction to the facility an insight into its
70. uns gua rantees a high quality measurement uropean Transonic Windtunnel User Guide 9 1 4 S IN 155 CONV 1 1 15 1 VIVA 13GON z 5 1 Model Data Acquisition The fact that ETW is a cryogenic wind tunnel has only a limited impact on the Model Data Acqusition system MDA A more important aspect is the ETW concept of using moveable model carts comprising the model model support test section top wall and an In strumentation Cabin IC so each model cart has the refore its own MDA system and directly related instru mentation This concept allows the complete model checkout including complete cool down before run As no personnel are ordinarily present in the IC during an actual test run of the tunnel all data acqui sition equipment can be operated by remote control dedicated computer located in the Instrumen tation Cabin controls each MDA system For security rea sons a dedicated fibre optic cable links it to the MTCR and the dedicated data reduction computer which is located in the User Room assigned to the client ETW s computer network incorporates a great amount of flexibility in ac cessing different systems and files from various locations It can be reconfigured physically and logically to meet the requirements of a particular test by means of junction boxes and star couplers Figure 23 shows the par

Download Pdf Manuals

Related Search

Related Contents

Samsung S22A300H Bruksanvisning  Genesis GLMT12 Use and Care Manual  カタログ    65から67頁 [PDFファイル／135KB]  Z-30 20N RJ Z  MANUAL DE INSTRUCCIONES MOTOSIERRA    Serie MINIBOX, MIDIBOX SINGLEBOX PLUS  Guide to electronic search  

Copyright © All rights reserved. Failed to retrieve file