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ESABASE2 Comova User Manual

1. 15 Geometry editor COMOVA page Outgassing Lab 16 Geometry editor COMOVA page Outgassing tab table 17 Geometry editor COMOVA page Chemical tab 19 Geometry editor COMOVA page Temperature tab 21 Geometry editor COMOVA page Temperature tab roable 22 Geometry editor COMOVA page Vents tab onen 23 Geometry editor COMOVA page Vents tab table 24 Geometry editor COMOVA page Column densities tab 25 Geometry editor COMOVA page Material tab 02 27 Geometry editor Meshing page 29 Copy amp paste of COMOVA system noe 30 COMOVA input edtor nano nenne nnnn nenne nenn nnnn nenne nenne nnnenn 31 COMOVA input editor Physics Lab 32 COMOVA input editor Raytracing and Numerics tab cccesceeseeeeeees 35 COMOVA input editor Result tab nenn nenn nnn nn 38 COMOVA input editor Ground test time steps Lab 41 COMOVA analysis Run button 42 COMOVA analysis Run dalog nenne nnnnn nenne nennen nennen 43 COMOVA result editor 2DResults nn nn nn en ann nn 44 COMOVA result editor 3D Results colour context menu 45 COMOVA result editor 3D Results Orbital Point context menu 48 COMOVA result editor 3D Results Coordinate Systems context menu 49 COMOVA result editor 3D Results Element Chart 50 ESABASE2 Contamination Outgassing Vents Software User Manual Reference R077 234rep 01 04 Software User Manual Solver
2. Name Fileca_FASSO1 A Molecule mass 18 0 atomic mass unit Diameter 47E 10 Sticking Captation temperature 1 23 0 Captation temperature width 1 4 0 Re emission time constant at reference temperature 0 036 Temperature dependence coefficient 0 0664 Reference temperature 250 sSelf scattering Ambient scattering Delete species Figure 2 9 Geometry editor COMOVA page Chemical tab You can define multiple chemical species A species is an ensemble of chemically identi cal molecular entities that can explore the same set of molecular energy levels on the time scale of the analysis A chemical species has besides a name the following pa rameters e Molecule mass The mass of one molecule of the species e Diameter The diameter of one molecule of the species e Sticking Toggles whether the species may stick to surfaces at all You can disable sticking for light molecules known not to stick at all analysis will be faster ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 19 53 giele ail Date Revision State Page 20 53 Captation temperature T and Captation temperature width AT Define the temperature span from 7 A7T to 7 AT in which bigger variations in sticking behaviour can occur
3. ESABASE2 Contamination Outgassing Vents Software User Manual Contract No Title ESA Technical Officer Prime Contractor Authors Date Reference Revision Status Confidentiality etamax space GmbH Richard Wagner Str 1 D 38106 Braunschweig Germany Tel 49 0 531 3802 404 Fax 49 0 531 3802 401 email esabase2 etamax de http www etamax de etamax space GmbH 16852 02 NL JA PC Version of Debris Impact Analysis Tool G Drolshagen J S rensen etamax space GmbH K Ruhl J Weiland 2010 02 10 RO77 234rep_01_03_Software_User_Manual_Solver_Comova doc 1 3 Final taya Table of Contents Document Information ee ee 3 l EEE SE SN 3 FA e ende 3 II ef e ef gen Ci EE 3 IV List of References EEE ENE 4 Me EN EE ESET 5 L EISEOT ADDEN AT ONG ee 5 VU BOTN nee ee 6 Te ge T L ON E 8 2 COMOV SN 9 2 1 COMOV Ee rn gn ee ea 9 11 MIN 10 2 12 PN 11 245 OM PIP 12 2 14 Material Page esse ness nes eat nern nee seta erinnere 27 2 1 5 MENA Je 29 2 1 0 COPY amp Raster reinen 30 2 2 COMOVA Input 31 221 PSTN 32 2 2 2 Raytracing and Numerics Tab 35 223 EI CRT kuden 38 2 2 4 Ground Test Time Steps Tab 41 25 OMAN urne 42 24 COMOVA ROSU S ii peie i eE 44 21 DROSS EE 44 ZZ G ee 51 245 e SE Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comov
4. e Only total contaminant masses and fluxes are given Toggles whether the results above will be shown separately for each involved chemical species or just the to tal results which is the summation of all species In the Time steps section you can specify either explicit time steps or combine addi tive selection criteria If you prefer explicit time steps you have to define a series of time steps separated by comma e g 10 0 1000 0 1350 5 The time steps are defined in seconds after mission start The time steps should be multiples of the time interval between orbital points defined in the ESABASE2 mission editor see core user manual 1 If you prefer a criteria based selection of orbital points the time steps are chosen dy namically according to the following criteria e At user defined orbital points For every n th orbital point generate results e g if this is set to 1 results will be generated for every orbital point If it set to 3 results will be generated for every third orbital point e At times for which temperature is given Generate results for each time step for which a temperature was defined see 2 1 3 4 ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 39 53 taya At an user defined number of point
5. o Above that range sticking will become nearly impossible everything will be reflected below that range sticking occurs almost always o The actual sticking coefficient is between 0 no sticking and 1 all stick ing and is described fully in the COMOVA technical descriptions 6 sec tion 3 3 1 Re emission variables If you want neither sticking nor reflection but instead the re emission of molecules after a certain delay use the following options more fully described in 6 section 3 3 2 o ke emission time constant at reference temperature How long it takes in seconds before the molecule is re emitted from the surface with a refer ence temperature given here o Temperature dependence coefficient Coefficient used together with the reference temperature o Reference temperature The reference temperature used to describe the re emission time constant above Usually the reference temperature is 25 C Self scattering Toggles whether this chemical species molecules can collide with each other in the analysis Ambient scattering Toggles whether this chemical species molecules can collide with the atmosphere molecules in the analysis 2010 02 10 ESABASE2 Contamination Outgassing Vents 1 3 Software User Manual Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail In the temperature tab you specify what
6. Qutqassing like amp Commanded Time Emission rate kgs 0 0 0 0 43200 0 2 9999999E T o6400 0 9 0000004E 12 129600 0 0 0 Create table Delete table Figure 2 13 Geometry editor COMOVA page Vents tab table The combobox at the top contains all vent tables Below the content of the vent table currently selected in the combobox is shown If you have chosen vent flux to be specified Commanded the two radio buttons right click into the table and choose Add Remove or Modify from the context menu A dialog will appear in which each table column here Time and Emission Rate are represented Press OK and the entry will be added as a row in the table Please note Once you have specified a vent table you can re use it for surfaces on en tirely different shapes That way you do not need to specify the same vent table twice Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 24 53 etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig giele ail 2 2 1 3 6 Column Densities Tab Column density is a term from astronomy and is used to define a cylinder with 1 cm base area between an optical instrument and an observed object It serves as a measure on how much the view is obstructed by molecules in the field of view In the column densities tab shown belo
7. GG ll O Replace PHYSICS_1MM FHYSICS TM Figure 2 4 Geometry editor COMOVA page Surface assignment Assigning a property to a surface works in the same way as the material editor see 1 After you have defined a property typically in the lower section select one of the 3 radio buttons to work in three different styles e All surfaces Assign the property to all surfaces of the shape This can be propa gated to children note propagation is a one shot action the children need to be already present to execute the propagation e ndividually For each surface of the shape make a dedicated assignment e Replace Replaces a previously selected property value with another value This can be propagated to already existing children as well In the following only the lower section of each tab will be discussed ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision 1 3 Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 13 53 giele ail 2 1 3 1 Physics Tab The physics tab is to define the physical properties of a surface For the time being the only physical property is the thickness of the surface it is always assumed the surface is a wall and the shape is not a solid The following figure shows the physics tab amp Shape Wizard Comova Box Size Meshing Position
8. 2 15 Geometry editor COMOVA page Material tab Materials specified in the material wizard page are used for multiple solvers Atmos phere Sunlight etc Therefore their attributes may vary Take care to select only ma terials with material properties relevant to COMOVA by setting the filter to COMOVA as shown in the figure above see also 1 for more on the material wizard ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 27 53 tayali In particular the COMOVA relevant material properties are Den Density in kg m e Cond Isotropic thermal conductivity in J m K s e Spec Specific heat at constant pressure in J kg K e Fmodu Isotropic Elasticity module in N m e POISS Poisson number dimensionless Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 28 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail Although the meshing page shown below is the same for all solvers the effects of the settings may vary 2 1 5 Meshing Page E Shape Wizard Meshing Box Size Meshing Position amp Attitude Kinematic Pointing Debris Comova Material Subdivison
9. Comova doc etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig Figure 2 30 COMOVA result editor LIStings rrrrrnnnnnrennnnnvrnnnnrennnnnrennnnrennnnnrennnnneennnnnen 51 Figure 2 31 Column densities result data structure 52 Figure 2 32 COMOVA result editor Notes 53 ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision 1 3 Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 7 53 giele ail 1 Introduction ESABASE2 is a software application and framework for space environment analyses which play a vital role in spacecraft mission planning Currently it encompasses De bris meteroid Atmosphere ionosphere Sunlight and Contamination outgassing vent analyses with this it complements other aspects of mission planning like thermal or power design The application grew from ESABASE2 Debris an application for space debris and micro meteoroid impact and damage analysis which in turn is based on the original ESABASE Debris software developed by the European Space Agency ESABASE2 adds a modern graphical user interface enabling the user to interactively establish and ma nipulate three dimensional spacecraft models and to display the selected orbit Analysis results can be displayed by means of the colour coded surfaces of the 3D spacecraft model and by means of various d
10. Figure 2 1 Geometry editor Kinematics page In COMOVA all kinematics are relative to the main body you cannot have joints which have child joints In defining the degrees of freedom for these joints the following restrictions apply e Translational degrees of freedom do not work in COMOVA and will therefore be ignored You can use only rotation e You can specify only 1 or 2 rotational degrees of freedom not 3 as usual A third degree of freedom will be ignored o If you specify just one degree of freedom the object will be treated as an attachment linked to the main body via an axis Specifying two degrees of freedom results in a ball joint type attachment e The minimum and maximum angle although editable in the page also have no effect in COMOVA Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 10 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail Pointing in geometries used for COMOVA analyses also has some restrictions when compared to other ESABASE2 solvers Consider the Pointing page shown below reach able by selecting a shape rightclick and choosing Modify gt Pointing 2 1 2 Pointing Page amp Shape Wizard Pointing Box Size Meshing Position amp Attitude Kinematic Pointing Debris Comova Material Inverse Direction VECI
11. Geometry editor COMOVA page The COMOVA page consists of several tabs all working on the surfaces of a shape e g one side of a cube with the exception of the chemical tab e Physics The thickness of a surface e Outgassing What kind and how much matter is emitted lost on a given surface e Chemical Defines chemical properties used in outgassing e Temperature How hot or cold the surface is at different times e Vents How much matter is emitted from the surface at different times e g for thrusters e Column densities Defines view direction vectors for which column densities can be computed a column density is the obstruction for optical instruments Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 12 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail As a common element each tab except Chemical has two sections e The upper section is for assigning a property to a surface all surfaces or perform a surface replacement e The lower section is for actually defining that property The figure below shows a typical property assignment part upper section of a tab Assign physical property tables to surfaces All surfaces leed edel Individually suface 7 PHYSICS Iki surface 8 PHYSICS IMM surface 9 PHYSICS TM
12. Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 53 53
13. RTV 5691 B DEPSMS RTV 5691 C DEPSMS RTV 5691 D 1000 2000 3000 4000 5000 6001 DEPSMS_RTV_S691_E l DEPSMS_RTV_S691_F Time Steps s gt D c at uw O a T 25E 9 Se Se Oo WW A Figure 2 29 COMOVA result editor 3D Results Element Chart From the Result Set combo box select a variable the appropriate graph for the given element will be displayed as shown on the right These are the same values that are colour coded in the element in the 3D view You also have the possibility to adjust the appearance of the graph via the Options button and to export the image as PNG or JPG via the Export Image button Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 50 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail When you run a COMOVA analysis ESABASE2 internally uses a COMOVA solver execu table which yields output text files which are then converted into a COMOVA result file In the Listings tab you can view these raw text outputs directly as shown in the figure below 2 4 2 Listings ESABASE2 File Edit Window Help GG CG GO E comovwa result 2009 12 14 18 43 23 Ch Reset perspective fe Result Log 5 NEUTRAL FILE Results AN RES ntf DATE 14 dec 2009 TIME 18 44 4 ENDSET PROP TAB DEF 3 1 PANEL DEN CON
14. The instantaneous deposited flux per second e DEPMSS kg elementf The total mass of deposited contaminant on surfaces counted per element not per square meter e DEPSMS kg m2 The surfacic mass of deposited contaminant per square meter e MPFLX kg ms The instantaneous impinging flux Impinging includes both deposited and reflected re emitted particles e OUTFLX kg m The instantaneous outgassed flux constantly subtracting from CNTSMS e REMFLX ko m s The instantaneous re emitted flux i e the impinging flux which is deposited and then re emitted as opposed to simply being reflected e Temperature C The temperature of the element Emissions from vents and outgassing have different units A vent is considered as a sin gularity i e has no surface and has an emission in kg s while outgassing flux is from a surface and is in kg m2 s However in order to be able to display emissions Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 46 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig taya from vents and from outgassing on the same plot the units of these emissions are both displayed in the same colour scale and unit kg m2 s for OUTFLX This display is simply wrong for vents and the displayed number is to be understood as in units of kg
15. amp Attitude Kinematic Pointing Debris Comova Material Column Densities Assign physical property tables to surfaces O All surfaces SHELL 1MM Individually surface 1 SHELL_1MM surface_2 SHELL IM surface 3 SHELL IM surface 4 SHELL IM surface 5 SHELL 1MM surface b SHELL MM O Replace PHYSICS MM PHYSICS 1MM Manage physical property tables Selecttable SHELL 1MM vi Name SHELL 1MM Shell thickness 0 0010 m Create table Delete table Figure 2 5 Geometry editor COMOVA page Physics tab In the lower part Manage physical property tables you can create multiple physical tables which you can re use for each shape of your model The content of a physical property consists of name and shell thickness as shown in the figure below Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 14 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail Manage physical property tables Selecttable SHELL_IMM v Name SHELL 1MM Shell thickness 0 0010 m Delete table Figure 2 6 Geometry editor COMOVA page Physics tab table Shell thickness is defined in m Please note that this is different from most other places in ESABASE2 which usually work
16. http www esa spaceweather net swenet ESABASE User Manual ESABASE GEN UM 070 Issue 1 Mathematics amp Software Division ESTEC March 1994 J F Roussel I Giunta C Lemcke COMOVA User Manual 1 1 10 SUM 1 1 10 ESA ESTEC Contract 12867 98 NL PA Contamination Modelling Onera DESP October 2006 J F Roussel I Giunta C Lemcke COMOVA 1 1 Technical Description S 189 97 TD ESA ESTEC Contract 12867 98 NL PA Contamination Modelling On era DESP March 2002 2010 02 10 ESABASE2 Contamination Outgassing Vents 1 3 Software User Manual Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig V Glossary Application ESABASE application such as e g the Debris or the Sun light application Eclipse Eclipse is an open source community whose projects are focused on providing an extensible development plat form and application frameworks for building software For detailed information refer to http www eclipse org ESABASE Unix based analysis software for various space applica tions For details refer to the ESABASE User Manual 4 ESABASE2 New ESABASE version running on PC based Windows platforms to be distinguished from the old Unix based ESABASE Geometric al analysis Flux and damage analysis of a full geometric model object pointing keyword tracking of a GEO satellite non geometric al analysis Flux a
17. mass normally all species should then add up to 100 e Outgassing time constant The outgassing time constant at reference tempera ture defined in seconds e Temperature dependence coefficient A coefficient used in combination with the outgassing time constant ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 17 53 giele ail In effect each surface can have multiple chemical species each with its own outgassing behaviour It is also possible to have the same species twice each time with different outgassing behaviour Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 18 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig 2 1 3 3 Chemical Tab The chemical tab shown below differs from the other tabs in that no assignment of chemical properties to surfaces is possible Instead chemical species are used in the out gassing tab see 2 1 3 2 Shape Wizard Comova Box Size Meshing Position amp Attitude Kinematic Pointing Debris Comova Material Physics Outgassing Chemical Temperature vents Column Densities Manage chemical species select species
18. of the shape s boundary surface into node areas na 1 nb 1 ne l Number of elements on a axis b axis c axis Ray Tracing Ray tracing weighting Factor Active Side default default both Colour positive negative none Figure 2 16 Geometry editor Meshing page Subdivision of surfaces i e surface nodes is not supported by COMOVA We recom mend using the Number of elements on settings for finer meshing Regarding active sides COMOVA always considers only the positive sides of elements the outside of volume shapes or the front of surfacic shapes in its analysis negative sides are not considered Any active side settings you do in the Meshing page will be ignored by the COMOVA solver ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision 1 3 Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 29 53 giele ail 2 1 6 Copy amp Paste If you want to transfer the COMOVA geometry settings from one geometry file to an other Copy amp Paste may come in handy In the geometry file all COMOVA property tables are stored under the node GeomModel SETTINGS COMOVA as pictured in the Out line view in the figure below EI ESABASE2 Explorer 2 1 e COMOVA_TC_01_test_SC LC ListingFiles 7 TO 01 test SC GI COMOVA_TC_02_exper_estec zk COMOVA_TC_0
19. row o If the outgassing table is used for a vent i e outgassing style in the Vents tab the thickness value is interpreted as the total available mate rial mass in kg and the thickness itself is ignored This is a case of pa rameter re dedication within COMOVA e Reference temperature The reference temperature for the outgassing time con stant parameter defined in each row Usually the reference temperature is 25 C The table rows are shown in the figure below Manage outgassing tables Select table Fileca FASYDNT 1 Name Fileca FASIN Reference thickness 0 0013 m Reference temperature 25 0 je Species name Percentage outgassed mass 1 Qutgassing time constant s Temperature dependence coefficient 1 8 Fileca FA3901 A 0 059 1 0 0 0664 Fileca_FAss01_6 0 091 10 0 0 0664 Fileca_FA3901_C 0 0010 100 0 0 0664 Fileca_FA3901_D 0015 S0000 0 0 0664 Create table Delete table Import tables Figure 2 8 Geometry editor COMOVA page Outgassing tab table An outgassing row contains the following entries right click the table to get a context menu for adding removing and editing rows and see the COMOVA technical descrip tion 6 section 3 2 1 for more details e Species name The chemical species defined in the chemical tab see 2 1 3 3 e Percentage outgassed mass Fraction of material mass that can be outgassed in percent o For commanded vents this is the percentage of the total emitted con taminant
20. s In case of the remaining mass CNTSMS the same is true whereas dis played in kg m2 on the colour scale as for the remaining contaminant mass the re maining vent mass relevant for continuously open vents only is to be understood as in units of kg Please note The number of options that is actually visible depend on your choices in the Result tab of the COMOVA input editor see 2 2 3 Only temperature will always be visible ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 47 53 giele ail 2 4 1 2 Time step When the COMOVA result editor opens it shows the analysis results for the first time step no mission results in COMOVA You can view the other time steps by opening the context menu and navigating to Time Step as shown in the following figure ESABASE2 File Edit Window Help Br Resetperspecive LG OG Cl Q ES comove result 2009 1 2 14 18 43 23 5 Gd ER 2 gd E DEPFLX Total Element Chart Colour gt Time Step gt Mission Time 0 0s Coordinate Systems gt Mission Time 200 0s Mission Time 400 05 Mission Time 600 08 Mission Time 800 08 Mission Time 1000 05 Mission Time 1200 0s Mission Time 1400 0s Mission Time 1600 0s Mission Time 1800 0s Mission Time 2000 0s Mission Time 2200 0s M
21. temperature a surface is at during different times of the mission The screenshot below shows the temperature tab 2 1 3 4 Temperature Tab 2 Shape Wizard Comova Box Size Meshing Position amp Attitude Kinematic Pointing Debris Comova Material Column Densities Assign temperature tables to surfaces All surfaces MO TEMPERATURE 0 C Propagate Individually surface 1 PANEL BACK surface PANEL FRONT surface 3 SC BUS surface 4 SC BUS surface 5 SC BUGS surface 6 NO TEMPERATURE 0C OReplace NO TEMPERATURE 0 C NO TEMPERATURE 0 C Propagate Manage temperature tables Selecttable SC_BUS EI ame ol BUS Temperature C 0 0 5 0 DU Create table Delete table Duplicate table Figure 2 10 Geometry editor COMOVA page Temperature tab In the lower part Manage temperature tables you can specify multiple temperature tables each consisting of a name and rows consisting of a point in time and a tempera ture as shown in the figure below ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 21 53 taya You have the possibility to duplicate an existing temperature table by using the Dupli cate button which allows creating temperature tables with identical point in times in a c
22. with mm The default physical table which is selected at start for each surface has a shell thick ness of 1 millimeter This has been done to be able to run a default analysis which in cludes computing of surfacic masses not yet outgassed Please note Vents and physical property table assignments in combination have a side effect When a surface is designed as a vent see 2 1 3 5 all surfaces that share the same physical property table used by that surface will be treated as vents too You should always create separated physical tables for vents ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 15 53 giele ail 2 1 3 2 Outgassing Tab In the outgassing tab you can define how much and which molecules are emitted by a surface as shown in the screenshot below amp Shape Wizard Comova Box Size Meshing Position amp Attitude Kinematic Pointing Debris Comoya Material Physics Outgassing Chemical Temperature Vents Column Densities Assign outgassing tables to surfaces O All surfaces Fileca FA3901 Individually surface_1 Fileca_FA3901 surface_2 Fileca FA3901 surface 3 RTY S691 surface 4 RTV_S691 surface 5 Fileca FA3901 surface b Fileca FA3901 O Replace NO OUTGASSING NO OUTGASSING Mana
23. 0 0 0 SUN vi VEC2 0 0 fo x Figure 2 2 Geometry editor Pointing page You can use both pointing vectors but only in the following directions e SUN The object shall always point with the given vector towards the sun e EARTH The object shall always point with the given vector towards the earth e VELOCITY The object shall always point with the given vector towards the direc tion of movement Do not use GEORELAY FIXED or FRAME they will be ignored ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision 1 3 Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 11 53 giele ail 2 1 3 COMOVA Page COMOVA is quite rich in the information pertinent to the spacecraft geometry In the geometry editor select a shape by leftclicking it open the context menu with a right click and choose Modify gt COMOVA The wizard shown in the figure below appears amp Shape Wizard Comova Cylinder Size Meshing Position amp Attitude Kinematic Pointing pon Coens Ya P ul Assign physical property tables to surfaces O All surfaces PHYSICS 1MM Individually surface 7 PHYSICS_1MM surface H PHYSICS 1MM surface 9 PHYSICS 1MM O Re place PHYSICS_1MM PHYSICS_1MM Manage physical property tables Selecttable Name Shell thickness Create table Figure 2 3
24. 3_vent_test 7 48 NEWPROJECT La eo atmosphere os COMDVA A geometry ionosphere WF mission 8 sunlight B Outline Eat GeomModel HC Configuration 288 Data 2 0 SETTINGS 09 ColourScales i CH 9 Geometry wu SCOPES 2 00 G0MOVA GE PHYS Modify GH CHEF Remove Be OUTI Rename HO TEMF Refresh a system Copy x C Materials Paste Dump Label ESABASE2 Explorer ES 750 3 5 COMOYA TC 01 test SC a ListingFiles AR TC 01 test SC TO 01 test SC WT 01 test GC ce COMOVA_TC_02_exper_estec sic COMOVA_TC_03_vent_test NEWPROJECT ll atmosphere A S comova Af debris geometr ionosphere Sg a mission 8 sunlight n Outline 72 E E GeomModel CH Configuration Geomet Mail ce scopes Femove a System Rename Refresh Copy Paste Dump Label Figure 2 17 Copy amp paste of COMOVA system node You can copy this node from one geometry file to another by rightclicking the comova node in the outline view of the source geometry file and selecting Copy in the con text menu In the target geometry file rightclick the SETTINGS node in the outline view and select Paste All property tables can now be used in the target geometry Date 2010 02 10 Revision 1 3 State Final Page 30 53 ESABASE2 Contamination Outgassing Vents Software User Manual Reference R077 234rep 01 04 Software User Manual Solver Comova doc etamax space GmbH R
25. 8 COMOVA result editor 3D Results Coordinate Systems context menu You can choose among the following coordinate system settings e No coordinates Note that pointing vectors will also be deactivated e Global coordinate system centred Shows the xyz axis for the entire system e Global coordinate system in the corner Same as before but in the corner of the system not centred e Global and local coordinate systems Shows xyz axis for each object Detailed but probably slightly irritating for complex S C geometries ontamination Outgassing Vent re User Manual Revision ue crte U 54 0D Ul UG SOTLWare USEC VI _ gt OIVer_ etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig Page 49 53 giele ail 2 4 1 4 Element Chart Apart from results for the entire spacecraft you can also view dedicated results for sin gle elements of the geometry in the form of 2D graphs called Element Chart Shift Leftclick an element of the S C geometry then open the context menu and select Element Chart The following figure shows the resulting small popup window Chart for element_8 Chart for element 8 Result Set tions Export Image Result Set DEPSMS_FILECALFA3301_B y Options Export Image DEPMSS_FILECA_FA3901_B DEPMSS_FILECA_FA3901_C DEPSMS_FILECA_FA3901_B vs time step for DEPMSS_FILECA_FA3901_D se DEPMSS RTV S691 A B za in m co DEPMSS Total DEPSMS FILECA FA3901 A DEPSMS
26. D SPECH EMODU FOISS 1000 0000 50 000000 850 00000 0 0000000 0 0000000 ENDSET PROP TAB DEF 2 1 SC BODY DEN 1000 0000 COND 10 000000 SPECH 0 80000000E 09 EMODU 0 0000000 POISS 0 0000000 ENDSET PROP TAB DEF 1 2 SHELL 1MM THICKE 0 100000006 02 ENDSET PROP TAB DEF 1 3 FILECA F43901 4 O 15E 02 25 FILECA FA5S01 A 0 59E 01 1 0 664 01 0 0 0 Motes Listings 30 Results Figure 2 30 COMOVA result editor Listings The tab is made of a combobox for selecting the file to view and a text area which shows the selected file The following files are available e COMOVA output file e COMOVA runtime log e Intermediate file ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision 1 3 Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 51 53 giele ail Detailed information about the contents of the listing files can be found in the original COMOVA user manual 5 Please note The listing files are foremost saved as data nodes in the COMOVA result file Additionally they are written in ASCII format to the Listings subfolder of the cur rent project folder in order to be more easily accessible to post processing tools 2 4 2 1 Column Density Results Column density results are not visualized in the 3D view but you can inspect the nu merical values in the COMOVA
27. E comove result 2009 1 2 14 18 43 23 ISI ll 4 wie STEEN re 3 23 COMOVA TC 01 test SC a zs P gogo ge GP j me ListingFiles DEPFLX Total TC 01 test SC TC 01 test SC 6E 12 4 5 COMOVA TC 02 exper estec 5 Outline 3 resDoc C Execution ES Reports a 1 SETTINGS a CH Orbital Point 1 a CH Orbital Point 2 a CH Orbital Point 3 C9 Orbital Point 4 2 Properties Property gt Notes Listings 3D Results Figure 2 25 COMOVA result editor 3D Results You can see a spacecraft geometry with element numbers visualised by colour codes on the elements and decoded by the colour scale on the right At the top of the editor the same toolbar as in the geometry editor appears allowing you to zoom rotate and scroll around the spacecraft yato 0 1 0 072 1 0 FCAPASED Cantaminati Or Outaassing antc Wale AV 1U UZ IV LJADRIELZ Contamination VU LQ assil IO V ents Ravicinr 2 CAatf inara llear Manil D VISIOn 1 5 Software User Manual Final Reference RUO 234rep 01 04 Software User Vlanual Solve Comova adaoc 14 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig taya Additionally you can rightclick into the 3D area to invoke the context menu which contains the following options e Colour Defines the result value to be laid over the S C geometry default is ele ment number e Time step Which time step to show note there are no combined mission re sults in COM
28. For each category of surfaces you can decide to ignore small view factors The view factor is the percentage of flux emitted by one surface that reaches another surface When a view factor is very small it might as well be ignored The surface categories for which you can finetune the settings are e Deposit sensitive surfaces Surfaces which are sensitive to deposits e Outgassing sensitive surfaces Surfaces which are sensitive to outgassing e Remaining surfaces All other surfaces that do not fall under the previous two categories The possible sensitivity values are Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 36 53 etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig giele ail e Only very small VF neglected Skip very small view factors during the computa tion e Most precise case Use all view factors e Only small VF neglected Skip small view factors during computation e Only large VF retained Use only large view factors during the computation e Only very large VF are retained Use only very large view factors during the com putation Finally in the Kinematics section you can define one parameter e Threshold angle for contiguration distinction Defines the threshold geometrical transformation rotation below which kinematic configurations do not need to
29. OVA e Coordinate Systems Whether to display coordinate systems alongside the S C geometry e Element Chart Shows the results for one single geometrical element select one with Shift Leftclick to enable 2 4 1 1 Colour COMOVA results come in multiple variables e g total density or temperature Only one of these variables at a time can be laid over the geometry model at once To choose a result set to be displayed rightclick the 3D view to open the context menu then choose Colour gt lt Variable gt as shown in the following figure ESABASE2 D8 File Edit Window Help Ek Reset perspective OB Q Ka ES comova result 2009 12 14 18 43 23 e 2 09800588 KI DEPFL Total 6E 12 GE Element Chart Colour gt Object Colour Time Step gt Object Number Coordinate Systems Surface Number Element Number EUR DEPFLX FILECA_FA3901_A DEPMSS FILECA_FA3901_B DEPSMS FILECA_FA3901_C OUTFLX FILECA FA3901 D REMFLX RTV 5691 Temperatures HIV 5691 B HIV 5691 C RTV 5691 D HIV 5691 E HIV 5691 F Notes Listings 3D Results Total Figure 2 26 COMOVA result editor 3D Results colour context menu Wa CD on Ant sS my in ati an N i tn acc ri nn an c SEZ CONTAMINATION UUTGQASSING VENTS oftware User Manual Revisior 12 oTtware User IManua REVISION 1 3 neTerence RU Z54rep Ul U4 software U ser Manual SOIVver COMOVA AOC Jlale INa etamax space GmbH Richard Wagner Stra e 1 38106 Braun
30. User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 38 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail In the Computed data section you can specify which physical quantities are to be provided as output e Surtacic masses of contaminant not yet outgassed The masses of contaminant material not yet outgassed Short CNTSMS kg m e Masses of deposited contaminant The masses of deposited contaminant im pinging minus reflected re emitted per element Short DEPMSS kg element e nstantaneous outgassed flux The outgassed flux Short OUTFLX kg m2 s e nstantaneous re emitted flux The re emitted flux Short REMFLX kg m2 s e nstantaneous impinging flux The impinging flux deposited plus reflected re emitted Short IMPFLX kg m2 s e nstantaneous deposited flux The deposited flux impinging minus re flected re emitted Short DEPSMS kg m e Volume density The volume density for each volume cell around the spacecraft o Please note These results will only be visible in the listing file not graphi cally in the 3D model of the spacecraft Short CNTDEN m e Column density The column density results for each column density defined in the geometry o Please note These results will only be visible in the listing file not graphi cally in the 3D model of the spacecraft Short CD TOTAL m gt and CD_OBSCUR
31. a doc Page 2 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail Document Information I Release Note Name Function Date Signature Established by K Ruhl Technical Project 2010 02 10 signed K Ruhl Manager Released by K D Bunte Project Manager 2010 01 14 signed K Bunte IL Revision History oa 20091102 KR 24 Addedresutfilehanding 2009 12 17 JW KR All Added details provided by Onera 2010 01 14 Added meshing information 1 2 2010 01 20 JW 2 1 3 5 2 2 2 Added column density paragraph and comments 2 4 2 1 on known bugs 2010 02 10 2 1 3 2 2 2 3 Updated figures 1 4 2010 03 18 JW 2 4 1 2 2 3 Added information about ground test and pointing vectors Minor grammar changes Ill Distribution List va ESABASE2 licensees ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 3 53 taya IV List of References 1 2 EI 4 5 6 Date Revision State Page 4 53 K Ruhl K D Bunte ESABASE2 Framework software user manual R077 230rep ESA ESTEC Contract 16852 02 NL JA PC Version of Debris Impact Analysis Tool etamax space 2009 ESABASE2 homepage http www esabase2 net SWENET ESA s Space Weather European Network since 2004
32. ains said options ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 41 53 giele ail 2 3 COMOVA Analysis To start a COMOVA analysis locate the Run Button in the toolbar press the arrow on the right side and choose either Run COMOVA Analysis or Run COMOVA ground test The figure below shows the run button ESABASE2 File Edit Window Help Ch Resetperspective Gr Gr Gs Ki EI ESABASE Explorer Run Comova Analysis al E Run Comoya Ground Test 2 3 COMOVA TC 01 test SC a TC 01 test SC La Figure 2 23 COMOVA analysis Run button You see the COMOVA run button among the Atmosphere lonosphere Sunlight and Debris run buttons There are two kinds of COMOVA analyses e COMOVA Analysis with mission file Uses a mission file to create an orbit e COMOVA Ground Test Analysis Uses the ground test time steps in the COMOVA input file No mission file needed Upon selecting the Run COMOVA Analysis option a Run dialog with two pages will appear as shown in the screenshot below Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 42 53 etamax space GmbH Richard Wagner Stra e 1 38106 B
33. be distinguished by the raytracing utility This is expressed as the maximum rota tion angle over all attachments of the spacecraft ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision 1 3 Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 37 53 giele ail 2 2 3 Results Tab The results tab is for specifying which results you want from a COMOVA run The avail able parameters are shown in the figure below TEE Ad eet Sc 5 E Result definition Computed data Surfacic mass of contaminant not yet outgassed Masses of deposited contaminant Instantaneous outgassed flux Instantaneous re emitted flux L Instantaneous impinging flux Instantaneous deposited flux volume density el Column density H Only total contaminant masses and fluxes are given Time steps Explicit time steps amp Combine additive selection criteria MI At user defined orbital points ho of points At interpolated orbital points Every user defined orbits For interpolated orbits J Attimes for which temperature is given Atan user defined number of points per orbit IM Every delta t a user defined time step delta t Physics Raytracing and Numerics Results Ground Test Time Steps Figure 2 21 COMOVA input editor Result tab Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software
34. e Atmosphere temperature in C The constant temperature of the atmosphere Variations are not taken into account Useful also for ground tests which need a defined constant background temperature e Mean velocity of atmosphere in km s in x y z direction Defines the velocity of the atmosphere i e the wind speed in the spacecraft reference frame Please note When you choose MSIS as atmosphere model and ambient scattering is enabled there are some transport parameter combinations that result in an analysis error This is a known but uninvestigated bug Please avoid the following and similar transport settings aam Lesen Number of reflections to model ii OE Number of collisions to model 0o Number of reflections for ambient species Ambient scattering Future versions of COMOVA will address this bug Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 34 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail As raytracing is a time consuming part of any analysis run it pays to adjust the settings for it The figure below shows all raytracing parameters 2 2 2 Raytracing and Numerics Tab Raytracing definition Total number of rays for raytracing from real surfaces Minimum number of rays per real surface Fixed number of rays per vent Total number of rays f
35. ge outgassing tables Select table Filece FA3901 D Name Fileca_FA3901 Reference thickness 0 0013 m Reference temperature 25 0 C Species name Percentage outgassed mass Outgassing time constant s Temperature dependence coefficient 1 K Fileca_FA3901_A 0 Fileca FA3901 B Fileca_FA3901_C 0 100 0 Fileca FA3901 D 0 015 50000 0 Create table Delete table Import tables Figure 2 7 Geometry editor COMOVA page Outgassing tab In the lower part Manage outgassing tables you can create multiple outgassing ta bles one of which can be assigned to each surface Another option is to import out gassing and chemical tables from an existing neutral file using the Import tables button By default the file dialog will show the COMOVA plugin data folder which contains the file outgassing table ntf This neutral file contains a broad list of outgassing defini tions and chemical species Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 16 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail An outgassing table has the following properties which are valid for all rows aside from the name of the table e Reference thickness The reference thickness in meter for the outgassing time constant parameter defined in each
36. iagrams The development of ESABASE2 was undertaken by etamax space GmbH under the European Space Agency contract No 16852 02 NL JA The first goal was to port ESABASE Debris and its framework user interface to the PC platform Microsoft Win dows and to create a modern user interface From the start the software architecture has been expressively designed to accommo date further applications the solvers outlined in the first paragraph were added and more modules are to follow ESABASE2 is written in Fortran 77 ANSI C and Java 6 The GUI is built on top of the Eclipse rich client platform with 3D visualisation and STEP import realised by Open CASCADE Report and graphs are based on the JFreeReport JFreeGraph libraries COMOVA is a contamination outgassing and vent analysis software written by Onera and HTS around 2002 6 Although it was not part of the original ESABASE framework a COMOVA interface has been developed within the ESABASE2 framework in order to address the contamination outgassing and vent analysis needs in mission planning This user manual is the Contamination Outgassing Vents handbook It complements the Framework user manual 1 which explains the common functionality of all solvers e g Debris Sunlight Atmosphere lonosphere and including COMOVA Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual So
37. ichard Wagner Stra e 1 38106 Braunschweig giele ail Complementing the COMOVA information within the geometry a global COMOVA in put file specifies further analysis parameters The figure below shows the COMOVA in put editor 2 2 COMOVA Input ESABASE2 File Edit Window Help Ch Resetperspecive Le C Q iD ESABASE2 Explorer 2 DV Eben a comova testing Physics definition Geet ur 2 6 to 5 44 Number of reflections to model Infinite H S ListingFiles No interpolation of mass transfer factor or sticking L RERNE coefficients between orbit points ETC 5 44 test SC U Reduce threshold distance between different pod es TC 5 44 test SC sticking coefficient sets for considering them as different by factor 2 k EE comova result 2010 01 tc_5_45 Number of collisions to model 8 6 ListingFiles I TC 5 45 exper estec w Number of reflections for ambient species gt DZ Outline a Comova H Physics 2 0 Results major components of atmosphere 4 Fileca FA3901 A E Properties 2 i 0 0 Property 10 0 0 0 y 00 Physics Raytracing and Numerics Results Ground Test Time Steps 5 Figure 2 18 COMOVA input editor The input editor has four different tabs see bottom concerned with different issues of a COMOVA analysis e Physics Reflection and scattering of molecules during the mission as well as den sity and constituent
38. ission Time 2400 0s Mission Time 2600 0s Mission Time 2800 0s Mission Time 3000 0s Mission Time 3200 0s Mission Time 3400 0s Mission Time 3600 05 Mission Time 3800 0s Mission Time 4000 0s Mission Time 4200 0s Mission Time 4400 05 Mission Time 4600 05 Mission Time 4800 08 Mission Time 5000 08 Mission Time 5200 08 Mission Time S400 0s Mission Time 5793 793s Notes Listings 3D Results Figure 2 27 COMOVA result editor 3D Results Orbital Point context menu In addition to the coordinate system Earth Sun and velocity direction are shown as de picted above earth in blue sun in yellow velocity in green These vectors do not exist for a ground test result and can therefore not be visualized in that case anual Solver OMO etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail To visualise the coordinate system you used previously in the geometry editor change the coordinate system by opening the context menu and navigating to Coordinate Systems as shown in the following figure 2 4 1 3 Coordinate Systems ESABASE2 File Edit Window Help ie Resetperspecive Le CC ES comove result 2009 1 2 14 18 43 23 5 SI Dot DEPFLX Total Element Chart Colour Time Step Coordinate Systems no coordinates global coordinate System centered default global coordinate system in the corner global and local coordinate systems Notes Listings 3D Results Figure 2 2
39. ity 0 0 m 3 Atmosphere temperature 0 0 T Mean velocity of atmosphere Ge 0 0 ha UU 0 0 km s Physics Raytracing and Numerics Results Ground Test Time Steps Figure 2 19 COMOVA input editor Physics tab The following parameters are available e Number of reflections to model Defines the number of reflections Valid values are from 0 to 999 or infinite with 0 to 3 being usual values o No interpolation of mass transfer factor or sticking coefficients between orbit points You should use this if you have a vent and infinite number of reflections because in this case interpolation inaccuracies are non negligible o Reduce threshold distance between different sticking coefficient sets for considering them as different by factor 2 Reducing the threshold dis tance results in a finer resolution of sticking coefficients use k 0 to 6 with 6 being the finest accuracy Useful e g for concave geometries where a lot of reflections occur Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 32 53 etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig giele ail e Number of collisions to model Defines the number of collisions between chemi cal species Usually 0 set to1 for low and 2 for very low earth orbits e Number of reflections for ambient species Defines the number of reflection
40. lver Comova doc Page 8 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail 2 COMOVA Solver COMOVA is the contamination and outgassing solver for analyses on spacecraft and missions defined within the ESABASE2 framework 1 When you have a spacecraft ge ometry and mission input file at hand you can run a COMOVA analysis Towards this purpose this chapter is split into four sections e COMOVA Geometry How to adapt your spacecraft geometry such that the shapes possess the required input parameters e COMOVA Input Describes the global COMOVA input parameters those that are not directly pertinent to the geometry e COMOVA Analysis How to run a COMOVA analysis e COMOVA Results How to interpret the results of a COMOVA analysis 2 1 COMOVA Geometry A major part of the settings for a COMOVA analysis is defined in the geometry editor the rest is defined in the COMOVA input editor Mostly you will use the geometry wizard pages e Kinematics Page Defines the movable parts of the spacecraft e g solar panel joints The settings slightly differ from the usual ESABASE2 kinematics e Pointing Page Defines where the movable parts of the spacecraft shall point to e g solar panel towards sun Also slightly different from the usual ESABASE2 handling e COMOVA Page Defines physics temperature outgassing and chemical tables column density parameters and vents This is the core information fo
41. mount of time steps varies from machine to machine This is a known issue although the reason is uncertain for the time being If you get this error it might help to put the ESABASE2 installation into a different folder or to specify more time steps Once you press Finish a progress dialog will appear and be updated over the course of the analysis When the analysis has finished a COMOVA output file will be created and opened in the COMOVA output editor which is described in the next section ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision 1 3 Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 43 53 giele ail 2 4 COMOVA Results A geometric COMOVA analysis produces a COMOVA result file which is interpreted by the COMOVA result editor The editor contains the following functionalities e 3D Results Shows the spacecraft geometry overlaid with the contamination or other output parameters e Listings Shows the NTF neutral file format output of the COMOVA solver ex ecutable This is the raw input used for the creation of the result file e Notes A blank text area for your own notes 2 4 1 3D Results The following figure shows the 3D Results tab in a COMOVA result editor amp ESABASE2 File Edit Window Help ae Resetperspecive Le Q Xp iD ESABASE2 Explorer
42. n define the accuracy of the atmospheric modelling e Only major atmosphere component 1 Use only the major atmosphere compo nent i e the most common molecule type usually atomic oxygen for LEO for the considered orbit Fastest option e Only atomic oxygen 2 Use only atomic oxygen e Only equivalent species 3 Use one equivalent species average of all available species as close as possible to the total atmosphere effect ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 33 53 giele ail e Major components of atmosphere 4 Use the major components of the atmos phere the densest species plus all species that have at least 10 of the densest one e All 7 species given by MSISe 90 5 Use all seven species given by MSISe 90 which are atomic oxygen molecular oxygen atomic nitrogen molecular nitrogen atomic hydrogen helium and argon Slowest option When defining your own atmosphere first import the species constitutive of the at mosphere from a geometry file coming from your spacecraft definition This ensures that the same chemical species used in the geometry file are used here Additionally define the three parameters below e Atmosphere density in Lon Density of the atmosphere in particles per m3
43. nd damage analysis of a plate which can be speci fied as a randomly tumbling plate or an oriented plate STEP Acronym which stands for the Standard for the Exchange of Product model data VI List of Abbreviations Abbreviation Graphical User Interface Java Virtual Machine NASA National Astronautics and Space Administration OCAF Open CASCADE Application Framework contains the ESABASE2 data model ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 5 53 giele ail VII List of Figures Figure 2 1 Figure 2 2 Figure 2 3 Figure 2 4 Figure 2 5 Figure 2 6 Figure 2 7 Figure 2 8 Figure 2 9 Figure 2 10 Figure 2 11 Figure 2 12 Figure 2 13 Figure 2 14 Figure 2 15 Figure 2 16 Figure 2 17 Figure 2 18 Figure 2 19 Figure 2 20 Figure 2 21 Figure 2 22 Figure 2 23 Figure 2 24 Figure 2 25 Figure 2 26 Figure 2 27 Figure 2 28 Figure 2 29 2010 02 10 Revision 1 3 Final Page 6 53 Geometry editor Kinematics page 10 Geometry editor POINTING page 11 Geometry editor COMOVA page 12 Geometry editor COMOVA page Surface ASSIGNMENT r rurnnnnnnnnnnvnnnnnnnnn 13 Geometry editor COMOVA page Physics tab Rn nn 00 14 Geometry editor COMOVA page Physics tab table
44. needed by COMOVA as a reference It cannot be changed ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 25 53 giele ail Computation method o From densities Densities are computed in each volume element of the volume mesh and the column density is derived from that by integration along the viewing direction in effect adding up the volume cells that obstruct the view o With computation of specific view factors Densities are computed on sev eral points on the viewing direction The points are obtained from specific computations based on special view factors which are ratios of local density to local outgassing fluxes on the spacecraft The column density is derived from that by integration along the viewing direction over values at those points View origin A 3D coordinate which defines the origin of the view By default the center of the reference element is used View direction A 3D coordinate which defines the direction of the view Creates together with the view origin a line of sight pointing away from the reference element Please note Date Revision State Page 26 53 Although the GUI supports the definition of column densities later on after the analysis the column density results are only shown in the Lis
45. onvenient manner Manage temperature tables Selecttable SC BUS vi Name GC BUS Time s Temperature C 0 0 0 0 2400 0 5 0 4300 0 8 0 Create table Delete table Duplicate table Figure 2 11 Geometry editor COMOVA page Temperature tab table A point in time is defined in seconds after mission start the temperature is defined in degree Celsius To add remove or modify a row right click into the table area to open a context menu which contains said options Please note that this is the effective temperature of a surface and should usually be the result of a thermal analysis No further temperature adjustments are made e g atmos phere heating from solar activity is ignored Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 22 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig 2 1 3 5 Vents Tab The vents tab is used for thrusters and other semi enclosed cavities Rather the losing a certain percentage of their material a vent emits matter directly the emitting sur face is the vent opening For this purpose you define multiple points in time when the emission changes as shown in the following figure Shape Wizard x Comova 2 La Plate Size Meshing Position amp Attitude Kinematic Pointing Debris Comova Mate
46. or raytrac ng from volumes Minimum number of rays per volume z S00 L Total number of rays for retracing from atmosphere 1 Total number of rays for raytrac ng for column densities KOD Minimum number of rays per column Use View Factor symmetries Numerics sensitivity parameter for neglecting small view factors to keep sparse matrices Depositsensitve surfaces most precise case I Qutgassing sensitwe surfaces most precise case D Remaining surfaces most precise case 0 Kinematics Define the threshold geometrical transformation rotation below which configurations do not need to be distinguished by the raytracing utility Threshold angle for configuration distinction Physics Raytracing and Numerics Results around Test Time Steps Figure 2 20 COMOVA input editor Raytracing and Numerics tab The following basic raytracing parameters are available e Total number of rays from for raytracing from real surfaces Defines the total number of rays used for all surfaces ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 35 53 giele ail e Minimum number of rays per real surface Defines the minimum number of rays used for each surface o During raytracing first the total number of rays is distributed to
47. output file AN_RES ntf at the end of the file For each time step a column density data block starting with COLUMN_DENSITIES_DAT is created The figure below shows the structure of these data blocks COLUMN DENSITIES DAT Time step Number of Chemical Species 2 for CD TOTAL and CD OBSCUR O nrOfChemicals pecies Chemicals peciesName CD TOTAL CD OBSCUR Number of Calumn Density results Number of Column Density results Number of Column Density results The nom ofthe view direction vectors The norm ofthe view direction vectors The nom ofthe view direction vectors specify the computed column density specify the computed column density specify the computed obscuration values i e density integrated along values i e density integrated along column density values i e obscuration the viewing direction in m 2 the viewing direction in m 2 alang the viewing direction This value is the sum of all chemical density x molecule section integrated species values alang viewing direction 1 1 nr fcolummDensityr esults ColumnDensityResult View Grigin Vector 1 nr fcolumnDensityResults View Direction Vector 1 nrOfColumnDensityR esults Figure 2 31 Column densities result data structure A column density block starts with the keyword COLUMN DENSITIES DAT followed by the current time step value and the number of child data blocks Child data blocks al ways include the data blocks CD TOTAL and CD OBSCUR and may con
48. r COMOVA geometries e Material Page Defines the materials and material attributes needed for COMOVA run e Meshing page Defines the granularity of meshing and which sides are consi dered active e Copy amp Paste How to transfer COMOVA settings from one geometry file to an other This may save you a lot of work for new projects A word on performance Be sensible with the number of elements and the number of time steps If both become large RAM may be exceeded and the analysis will stop A good rule of thumb is Number of elements Number of time steps lt 30 000 ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 9 53 giele ail 2 1 1 Kinematics Page Kinematics for geometries used in a COMOVA analysis have certain restrictions when compared to other ESABASER2 solvers Consider the Kinematics page shown below reachable by selecting a shape rightclick and choosing Modify gt Kinematics Shape Wizard Kinematic Box Size Meshing Position amp Attitude Kinematic Pointing Debris Comova Material Translational Degrees of Freedom mm x gt 1 10 0 10 0 0 0 loo 0 0 o o Rotational Degrees of Freedom deg x y rmin rmax 1 1 0 0 Jo 00 00 2 00 0 0 0 0 0 0 3 00 00 00 o
49. raunschweig PB Comova Analysis Comova Analysis Export to ZIP file Please choose the input files for the analysis Please select if you want to export the results Project COMOVA TC 01 test SC Exportto ZIP file will save all files first Satellite TC 01 test SC 2 Export geometry file Export mission file Mission TC 01 test SC Export Comova file Comova TC 01 test SC Export result file Target directory for export Ka i Generate output filename Filename comova result 2009 12 14 18 38 02 Comment that will be included in the filename FEI Figure 2 24 COMOVA analysis Run dialog As in the other solvers you first choose the project from your workspace for the space craft the mission and the COMOVA input file only files from that projects will be se lectable as shown on the left We recommend to always generate an output file name a template name with the cur rent date and time as part of the file name is proposed Press either Finish to start the analysis or choose Next if you want the results plus input files to be exported to a ZIP file as shown in the right The only difference when selecting a ground test is that you do not need to specify a mission file COMOVA will use the time steps that you defined in the COMOVA input file in that case There exists a bug in the COMOVA pre processor which appears when a certain amount of time steps were specified The exact a
50. rial Column Densities Assign vent tables to surfaces All surfaces ven z Propagate O Replace NO VENT NO MENT Fropagate Caution When surface is designed as vent all surfaces using the physical property table used by this surface will be treated as vents Manage vent tables Yentflux Qutgassing like Commanded Emission rate kgs DU 2 9999999E 11 9 00000046 12 0 0 Create table Delete table Figure 2 12 Geometry editor COMOVA page Vents tab In the lower section Manage vent tables you can create multiple vent tables Vent tables can be defined in two different styles e Outgassing like The amount of vented material is determined by the outgassing specification see 2 1 3 2 e Commanded Each vent table contains multiple points in time in which the emis sion rate changes ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 23 53 giele ail If you choose the former no further specification in this tab is needed If you choose the latter you have to specify several points in time in seconds after mis sion start and the emission rate in kg s for each of these points in time as shown in the figure below Manage vent tables Selecttable Wentz A Name vent 2 vent flux
51. s for ambient species i e the atmosphere around the spacecraft These bouncing molecules can hit the ram face of the spacecraft thus increasing atmospheric drag e Self scattering Toggles whether self scattering collision of outgassed molecules with themselves should be integrated into the calculation Self scattering can be enabled if the number of collisions to model was set to a value bigger than zero e Ambient scattering Toggles whether ambient scattering collision of outgassed molecules with the atmosphere should be integrated into the calculation Am bient scattering can be enabled if the number of collisions to model and the number of reflections for ambient species were set to a value bigger than zero Mass transfer factors including reflections are only computed for a few reference stick ing coefficient sets During the computation for an arbitrary sticking coefficient set the mass transfer factor obtained from the nearest reference sticking coefficient set is used which involves a small error This error can be reduced by reducing the threshold dis tance that triggers the computation of another reference sticking coefficient set If ambient scattering is enabled you can define the atmosphere which surrounds the Spacecraft by choosing one of the three following options e No atmosphere e MSISe 90 model e User defined atmosphere Having no atmosphere has no further options When choosing an MSISe 90 model you ca
52. s of the atmospheric conditions the spacecraft goes through e Raytracing and Numerics Allows fine adjustment of raytracing detail raytracing is the most time consuming activity in COMOVA e Results Which results to produce e Ground Test Time Steps Allows the input of time steps which are needed for a COMOVA ground test run The following subsections describe the tabs ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User Manual Revision 1 3 Reference R077 234rep 01 04 Software User Manual Solver Comova doc State Final etamax space GmbH Richard Wagner StraBe 1 38106 Braunschweig Page 31 53 giele ail 2 2 1 Physics Tab The physics tab defines the number of molecular reflections and collisions to model as well as the atmospheric conditions surrounding the spacecraft as shown in the screen shot below TC_5_44_test_SC i m Physics definition Number of reflections to model n 1 Cl Infinite No interpolation of mass transfer factor or sticking coefficients between orbit points Reduce threshold distance between different k E sticking coefficient sets for considering them as different by factor 2 k Number of collisions to model 1 Number of reflections for ambient species 1 self scattering Ambient scattering O No atmosphere OMSISe 90 model major components of atmosphere 4 User defined atmosphere Species constitutive ofthe atmosphere Fileca_FA3901_A Atmosphere dens
53. s per orbit Divides the orbit into n points and generates a result for each point e Every delta t a user defined time step Every specified time step a result will be generated In the original COMOVA further options were available if multiple orbits were de fined They have been deactivated in ESABASE2 because the mission editor only defines one orbit e At interpolated orbital points e Every user defined orbits e For interpolated orbits Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 40 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail The ground test time steps tab is used to create a list of time steps for which results shall be calculated It is used in the COMOVA ground test analysis 2 2 4 Ground Test Time Steps Tab TCO 5 45 experestec E3 7 Ground test time steps Hour hh Minute min second sec seconds s 0 0 0 0 0 zA UI ob400 0 40 0 0 172000 0 fe 0 0 259200 0 4h 0 0 345600 0 120 UI 432000 0 Physics Raytracing and Numerics Results Ground Test Time Steps Figure 2 22 COMOVA input editor Ground test time steps tab Time steps are shown separated in hours minutes seconds as well as in total number of seconds To add remove or modify a time step right click into the table area to open a context menu which cont
54. schweig Page 45 53 taya The first 4 items in the context menu are not part of the COMOVA results instead they are used to gain an overview of the spacecraft geometry and particular its objects sur faces and elements e Object Colour Displays exactly the same object colour which was used in the ge ometry editor e Object Number Each object is identified by an object number In this overlay this object number is mapped to colours o Leftclick on an object in the 3D view to select it and then look at the col our scale to the right The appropriate colour will be marked and the ob ject number will be shown e Surface Number Breaking down the objects each surface is shown in a different colour o Ctrl leftclick on a surface in the 3D view to select it The respective surface number is marked in the colour scale to the right e Element Number Further breaking down the surfaces each element is shown in a different colour o Shift leftclick on an element in the 3D view The selected element num ber and color will be marked in the color scale The following 9 items show the respective quantity listed below as colours on the ele ments of the geometry model To see the exact value on an element Shift leftclick the element the colour scale on the right will then show the quantity value e CNTSMS kg m f The surfacic masses of contaminant not yet outgassed i e re maining in the emitting material e DEPFLX kg m
55. tain a number of chemical species blocks if you deactivated Only total contaminant masses and fluxes are given in the result tab of the COMOVA input editor see 2 2 3 Each child data block has a column density result for each column density you defined in the column densities tab of the geometry editor COMOVA page see 2 1 3 6 A result consists of the view origin vector and the view direction vector The actual computed column density values can be derived from each view direction vector by calculating its norm We know that this is a strange way to express it but this is the implementation Date 2010 02 10 ESABASE2 Contamination Outgassing Vents Revision 1 3 Software User Manual State Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc Page 52 53 etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig taya 2 4 3 Notes The figure below shows the Notes tab within the COMOVA result editor ESABASE2 File Edit Window Help Ch 3 Reset perspective 3 e GO Er E comova result 2009 12 14 18 43 23 53 a Here you can enter notes for this result file Motes Listings 30 Results Figure 2 32 COMOVA result editor Notes It consists of a simple text area where you can write your notes concerning the COMOVA results Your text will be saved and is available to whomever you may send the COMOVA result file ESABASE2 Contamination Outgassing Vents Date 2010 02 10 Software User
56. the sur faces according to their respective surface areas Then any surface not getting the minimum number of rays is supplemented with additional rays e Fixed number of rays per vent Defines the number of rays used for each vent e Total number of rays for raytracing from volumes Defines the total amount of rays used for the volume cells surrounding the spacecraft for backscattering of emitted molecules to spacecraft e Minimum number of rays per volume Defines the minimum amount of rays used for each volume cell sourrounding the spacecraft e Total number of rays for raytracing from atmosphere Defines the total amount of rays used for the effect of atmospheric particles e Total number of rays for raytracing for column densities Defines the total amount of rays used for the column densities o A column density is a cylinder usually of 1 cm base area from an optical instrument to a far object The number of molecules in it determines how much the view is obstructed e Mininum number of rays per column Defines the minimum amount of rays used for each column density Total minimum number of rays works the same way as for real surfaces see above e Use View Factor symmetries Toggles the usage of view factor symmetries in the raytracing process This is good for fluxes on small surfaces is usually enabled and more fully described in 6 In the Numerics section further parameters can limit the computational effort
57. ting file and are not visualised in the 3D view of the result editor The computation method From densities only produces zero value results This is a known bug however the cause of this error is currently unknown Please use always with computation of specific view factors as the computation method until the bug is fixed 2010 02 10 ESABASE2 Contamination Outgassing Vents 1 3 Software User Manual Final Reference R077 234rep 01 04 Software User Manual Solver Comova doc etamax space GmbH Richard Wagner Stra e 1 38106 Braunschweig giele ail COMOVA interprets material definitions on the spacecraft To define material surfaces select an object in the geometry editor right click to open the context menu and choose Modify gt Material The wizard shown in the figure below will open 2 1 4 Material Page amp Shape Wizard Material Plate Size Meshing Position amp Attitude Kinematic Pointing Debris Comova Material Surfaces All surfaces PANEL vi _ Propagate O Individually PANEL OReplace PANEL PANEL Materials Materials used in file Materials available in library PANEL ALU SC BODY Aluminiumoxynitrid Aluminum GENERIC_ISOTROPI KAP2 Hide material attributes Name GENERIC_ISOTROPI 1 Comova on on 0 0 0 0 on on 10 0 10 0 L L on Den 29200 45 0 Emodu 2 068E11 0 29 Figure
58. w you can define a set of input parameters used for the calculation of column densities and assign them directly to surfaces Unlike in the previous tabs the surfaces do not share these sets instead each surface holds its own set of column density parameters amp Shape Wizard Comova Plate Size Meshing Position amp Attitude Kinematic Pointing Debris Comoya Material Assign column densities to surfaces Select suface surface 10 w Only surfaces with a single element are shown Column densities assigned to the selected surface Reference element Computation method View origin View direction Element 32 from densities 0 5 0 5 1 01 1 0 0 0 0 0 Element 327 with computation of specific view factors 0 5 0 5 1 01 1 0 1 0 0 0 Figure 2 14 Geometry editor COMOVA page Column densities tab In the top part you can choose the surface for which you want to define column density parameters You can assign column density parameters only to surfaces which are made of a single element e g one side of a plate This way it is clearly defined which ele ment will be the origin of the column densities In the table at the bottom you can define multiple column density sets To add remove or modify a row right click into the table area to open a context menu which contains the appropriate actions A column density parameter set contains the following parameters e Reference element This is the single element of the surface which is

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