Gaia M-SVM. Thermal Modelling Specification. EADS Astrium. U.Rauscher. R. Kerner M-SVM system engineering

Transcription

1 Page 1 of 28 Title Thermal Modelling Specification Name and Function Date Signature Prepared by U.Rauscher Checked by: R. Kerner system engineering Approved by: R. Kerner system engineering L. Gessler PA Manager Authorised by: M. Schelkle Project manager Application Authorised by: C. Lebranchu GAIA Procurement APM The copyright in this document is the property of EADS ASTRIUM GmbH and the contents may not be

2 Page 2 of 28 CONTENTS 1. SCOPE APPLICABLE DOCUMENTS Reference Documents LIST OF ACRONYMS THERMAL MODELS STRUCTURE MODEL HIERARCHY BREAKDOWN OF MODELS MODEL DELIVERY STRUCTURE OF MODEL FILES APPLIED PHILOSOPHY Geometrical Mathematical Models (GMM) Thermal Mathematical Model (TMM) Model Organisation in Directories FILE NAMES FILE HEADERS COMMENTS GENERAL REQUIREMENT COORDINATE AXIS DEFINITION Spacecraft Coordinate System Unit Coordinate System UNIT SYSTEM REFERENCE CASE DELIVERABLE DOCUMENTATION THERMAL LOAD CASE DEFINITION GEOMETRICAL MODEL SPECIFIC REQUIREMENTS ELEMENT REPRESENTATION THERMO-OPTICAL PROPERTIES OF MATERIALS ADDITIONAL PROCESSING TO OBTAIN ESATAN INPUT THERMAL MODEL SPECIFIC REQUIREMENTS ELEMENT REPRESENTATION MODEL MONITORING LOGIC COUPLINGS TRANSIENT SENSITIVITY ANALYSES PROGRAMMING STANDARDS MODEL ACCEPTANCE THERMAL MODEL ACCEPTANCE GEOMETRICAL MODEL ACCEPTANCE...22

3 Page 3 of SCOPE This document specifies the requirements for the construction and delivery of the thermal software models (geometrical mathematical models (GMM) and thermal mathematical models (TMM)). A detailed description of the Thermal and Geometrical Mathematical Model structures is given in this document. 1.1 APPLICABLE DOCUMENTS AD 01 GAIA.ASF.SP.SAT.00002: GAIA General Design and Interface Requirement Specification 1.2 Reference Documents RD 01 Natural Environment near the Sun/Earth-Moon L2 Libration Point, Steven W. Evans, Marshal Space Flight Center (MSFC), Alabama, p LIST OF ACRONYMS AD Applicable document AU Astronomical Unit BOL Begin of Life EOL End of Life GMM Geometrical Mathematical Model I/F Interface LOS Line of Sight MLI Multi Layer Insulation RD Reference Document S/C Spacecraft S/W Software TBC To Be Confirmed TBD To Be Determined TMM Thermal Mathematical Model

4 Page 4 of THERMAL MODELS STRUCTURE 2.1 MODEL HIERARCHY Project thermal models are defined at different levels: Level 1 satellite or system Level 2 module or sub-system Level 3 equipment, antennae or instrument 2.2 BREAKDOWN OF MODELS Figure 2-1 shows an example breakdown of the GAIA project model highlighting the different levels in the model hierarchy. The four characters used for the component names are given as guidelines only. LEVEL 1 Top Level Model of Project GAIA (Satellite / System) LEVEL 2 Module SVM Module PLM Module DSA LEVEL 3 Equipment Antenna Instrument Figure 2-1: Structure of GAIA Project Models

5 Page 5 of MODEL DELIVERY Each model shall be electronically delivered in the form of one single zipped archive file, along with: its model documentation provided in WinWord / RTF / PDF format an associated text file.txt which describes the delivered files, allowing the files to be easily understood and used. These files shall be named according to: Name_ v1_ddmmyy.ext, where: Name is the model name as agreed at prime level v1 is the version number identifying the model (revision / issue) ddmmyy is the date Ext is the extension characterizing the model file:.zip for the zipped archive file format,.doc for the Word file (or.pdf),.txt for the delivery description helping file.

6 Page 6 of STRUCTURE OF MODEL FILES 3.1 APPLIED PHILOSOPHY The general idea is to apply a classical principle of software engineering, enabling a better management of complex applications (models): Modularity: partly achieved by the use of models, sub-models and subroutines. The application is broken down into several smaller parts, which are handled more easily. The structure will be efficient, through the use of command tool files (shellscripts, makefile) allowing the files used to be automatically created and updated. The application of this approach is described in the following paragraphs Geometrical Mathematical Models (GMM) The approach is applicable to ESARAD generated geometrical mathematical models The geometrical shapes are defined in a top-level file with only generic material optical properties referenced. This means no beginning of life or end of life material names and the removal of direct definitions for thermo-optical properties associated to shapes (usual in SYSBAS THERMICA standard files). A directory for each application case is then created, containing the corresponding geometry and the associated dated materials data. In the case of different geometrical configurations (stowed, deployed), the geometry shall be organised in several different files. Figure 3-1 shows the configurations for ESARAD. Radiative couplings and external fluxes production should be defined at the top-level model. ESARAD implementation: Modularity: management in the central database of each sub-model along with its associated thermo-optical properties. The sub-models are then called at the top-level by the INCLUDE_MODEL statement. Each submodel in the database uses dated properties and consequently several different model names are necessary. Note: The PLM sub-model to be included in the main ESARAD model will be a reduced model, whereas the detailed PLM model will be built up using SYSTEMA.

7 Page 7 of 28 ESARAD EXTERNAL INTERNAL HOT1 COLD1 STOWED1 SVM: svmneol.erg svmnbol.erg svmnbol.erg svmnint.erg PLM: plmneol.erg plmnbol.erg plmnbol.erg plmnint.erg DSA: dsadeol.erg dsadbol.erg dsasbol.erg INCLUDE_MODEL INCLUDE_MODEL INCLUDE_MODEL INCLUDE_MODEL gaianeol.erg gaianbol.erg gaiasbol.erg gaianint.erg gaianeol.erk gaianbol.erk gaiasbol.erk gaianint.erk gaianeol.ere gaianbol.ere gaiasbol.ere gaianint.ere gaianeol.tan gaianbol.tan gaiasbol.tan gaianint.tan Figure 3-1: GMM File Structure with ESARAD Comments about Figure 3-1 The HOT1 directory contains all the necessary files to run the HOT1 case with ESARAD: ESARAD sub-models definitions (svmneol.erg, plmneol.erg, dsadeol.erg). These sub-models shall be loaded into the database before being included in the current level model. The geometric model file for the HOT1 case (gaianeol.erg). It includes the files described above (sub-models, geometry and EOL thermo-optical properties) using INCLUDE or INCLUDE_MODEL statements. The satellite orbit and altitude for the hot case are both defined in the kernel file (gaianeol.erk). The file (gaianeol.ere) allows the generation of the ESATAN input file for the HOT1 case. The directory COLD1 is built in a similar way as the HOT1. The COLD1 case uses the same configuration as HOT1, but with thermo-optical properties of a different age (beginning of life in the COLD1 case). The STOWED1 directory is similar to COLD1 with regard to the BOL thermo-optical properties and the configuration of the PLM and SVM sub-models. The DSA sub-model contains the stowed configuration instead. o The three cases have different kernel files.

8 Page 8 of Thermal Mathematical Model (TMM) For flight calculations only one generic file structure is used for the thermal mathematical models (ESATAN), located in each computation case directory. The files will be pointed to by symbolic link from the corresponding Esarad output directory and will include a case defining parameter input file (param.inp). A typical thermal run that covers the majority of cases could be described as follows: A single radiative couplings / external fluxes data set from a GMM run (which may correspond to several successive attitudes) Run of one of the three following cases: steady state alone steady state + transient transient from a set of initial temperatures (A file of initial temperatures is incorporated hrough the use of OPEN/READ/CLOSE FORTRAN commands). The generic file consists of all codes manually created involving all computation cases (internal dissipations, heating, etc). Also included is the algorithm required to direct the user toward the correct configuration utilising the appropriate parameters. These parameters, dissipation, heating types, etc. along with the necessary ESATAN monitoring variables, are defined in each computation case directory in a file called param.inp. This file is incorporated into the generic file through the use of either $INCLUDE statements or OPEN/READ/CLOSE FORTRAN commands. The advantage of the FORTRAN commands is that the FORTRAN Compiler and Loader do not have to be executed every time a parameter is altered in the param.inp file. Again, to follow the modularity principle, the following should be adopted: ESARAD output files shall be broken down into several files corresponding to each data type (radiative couplings, flux tables and subroutines). These files are then called with the ESATAN $INCLUDE statement in the generic model file. With this rationale, the only differences between the cases is the GMM data. This data is defined in standard name files (so that they can be called through the $INCLUDE statement in the generic file). These files shall be placed in each computation case directory or referred to elsewhere through symbolic links. As an example see Figure 3-2.

9 Page 9 of 28 ESATAN HOT1 COLD1 STOWED1 Esarad output files (ext. & int.): gaianeol.tan gaianint.tan gaianbol.tan gaianint.tan gaiasbol.tan gaianint.tan ESARAD/ EXTERNAL/ HOT1 (HOT1 case files directory) gaia_igr.esa (external GRs files) gaia_eqa.esa (ext. flux tables files) gaia_eqi.esa (flux subroutines files) gaia_int.esa (internal GRs files) ESARAD/ EXTERNAL/ COLD1 gaia_igr.esa gaia_eqa.esa gaia_eqi.esa gaia_int.esa ESARAD/ EXTERNAL/ STOWED1 gaia_igr.esa gaia_eqa.esa gaia_eqi.esa gaia_int.esa INCLUDE INCLUDE INCLUDE ESATAN/ HOT1 gaia.esa param.inp ESATAN/ COLD1 gaia.esa param.inp ESATAN/ STOWED1 gaia.esa param.inp Figure 3-2: TMM File Structure with ESATAN (Coupled with an ESARAD GMM) Comments about Figure 3-2 ESATAN sub-models, such as plm.esa, svm.esa and dsa.esa (not shown in the above figure), are included in the main Esatan model gaia.esa using the $INCLUDE statements. $INCLUDE statements are used to: Load the files corresponding to a GMM output run. That is the internal and external radiative couplings (gaia_int.esa and gaia_igr.esa), the transient flux tables (gaia_eqa.esa) and the flux subroutines (gaia_eqi.esa). These files are accessed in the ESATAN directory by using symbolic links to the associated GMM directory. OPEN / READ / CLOSE statements are used to input the ESATAN run parameter values, global variables and control constants, specific to the case studied (param.inp). The HOT1 directory comprises all necessary files to run the HOT1 case with ESATAN: ESARAD output files for the current model and all sub-models; placed in a particular directory (ESARAD / HOT1), these files can be accessed by symbolic links. ESATAN global variables and control constants parameter file, associated to the case studied. The COLD1 and the STOWED1 directories are structured in a similar way as the HOT1. The differences are the particular GMM output files used and the parameters in the param.inp files.

10 Page 10 of Model Organisation in Directories The following structure has already been discussed in section 3.1. Figure 3-3 shows the overall organisation of the files. Model GAIA_v1 Submodels PLM, SVM, DSA Model GAIA ESARAD ESATAN ESARAD ESATAN INTERNAL EXTERNAL HOT1 COLD1 STOWED1 HOT1 COLD1 STOWED1 Figure 3-3: Organisation of Directories Associated to a TMM 3.2 FILE NAMES The file names shall be identical to the model names they are associated with. Although it may be necessary to have specific file names, tailor made for the project, the following should be used as a guideline for the file names structure. The files names shall have the following format: xxx(x)yzzz_suf.ext using lower-case letters only (to be differentiated from ESATAN output files), where xxx is the sub-system (plm, svm, dsa) as defined in section 2.2 xxxx is the system (gaia) as defined in section 2.2 y defines the configuration, according to Table 3-1, for sub-model level only zzz defines the model type as indicated in Table 3-2, for sub-model level only suf is the suffix that shall only be used to characterise the main ESARAD model (internal/ external) or ESATAN input files, Table 3-3. The suffix names in this table are recommended names if external files are to be used instead of including the code directly. The file extension.ext characterises the model file type, Table 3-4. This table is not an exhaustive list of model file types. Other ESATAN output file types may be used however these are dependant on the subroutines called and the post-processing executed.

11 Page 11 of 28 Code Model involved Description n GMM Geometrical (ESARAD) models nominal configuration. s GMM Geometrical model stowed configuration (DSA only). d GMM Geometrical model deployed configuration (DSA only). Table 3-1: Model Configuration Code Code Model involved Description bol GMM External Beginning of life thermo-optical properties. eol GMM End of life thermo-optical properties. int GMM Internal geometrical model. Table 3-2: Model Type Code Code nds igr int eqa eqi cpl ifc qi qr Description Node declaration (geometrical, i.e. radiative nodes). External radiative couplings generated by ESARAD. Internal radiative couplings generated by ESARAD (by enclosure if possible). Transient flux or GR tables generated by ESARAD. Transient flux or GR subroutines generated by ESARAD. All model couplings, when not broken down in smaller files. Interface couplings with / between sub-models. Internal power (dissipation). Heating power. Table 3-3: Input File Code Code Model involved Description erg GMM Geometrical model file, self-content or calling some other files using $INCLUDE. erk GMM Orbit, pointing, fluxes and associated radiative couplings computation definition. ere GMM Output instructions for ESARAD s results (node data, infrared REFs, absorbed heat fluxes). The results will be in the form of an ESATAN input file. tan GMM ESATAN format output file. esa TMM Model file, self-content or calling some other files using $INCLUDE. tinit TMM Complete set of initial temperatures. OUT TMM Main ESATAN Output Table 3-4: Model File Extension Code

12 Page 12 of FILE HEADERS Each file shall include a header containing information according to the following format: Name / file description Current version: file name, version, review, date Software compatibility: name; version Author: name / company File characterization: geometrical configuration (stowed, deployed,...), thermooptical properties, case (season, attitude) NAME DATE CHANGES COMMENTS When created, the model code shall contain lots of comment statements. Code updates for the current review shall be indicated by Vx.y /date/author initials + comments. Example : V4.5 : 13/03/01 /FJ/ Equipment coupling update according to sub-contractor fax ref Changes are to be commented in the file header.

13 Page 13 of GENERAL REQUIREMENT 4.1 COORDINATE AXIS DEFINITION Spacecraft Coordinate System The coordinate axis systems shall be in accordance to the systems defined in Figure 4-1. All coordinate systems shall be right-handed orthogonal systems. These axes shall be used for the definition of geometrical models: Satellite reference Sub-system reference Equipment reference (general rule: +Z orthogonal to the exposure plane). The satellite coordinate system (C S, X S, Y S, Z S ) is shown in Figure 4-1. X S Astro LOS 1 = Astro FPA = Astro LOS 2 Satellite-launcher interface Bissector plane C S Z S Y S Figure 4-1: Satellite coordinate system It is defined by: C S, origin: at the center of the circular satellite interface with the launch vehicle adapter, in the separation plane, X S axis: launcher axis, oriented from launcher interface to satellite,

14 Page 14 of 28 Z S axis: intersection of the separation plane and of the bisector plane of both planes, one parallel to X S and containing the first Astro line of sight, the other one parallel to X S and containing the second Astro line of sight; Zs is oriented towards the Astro Focal Plane Assembly, Y S axis: in the separation plane, perpendicular to Z S. The SVM and DSA coordinate systems are identical to the satellite coordinate system. The Payload Module coordinate system (C P, X P, Y P, Z P ) is defined by: C P, origin: at the intersection of the Service Module Payload Module mechanical interface plane with the X S axis, X P, Y P, Z P are respectively parallel to X S, Y S, Z S and have the same orientation Unit Coordinate System The (C u, X u, Y u, Z u ) unit coordinate systems are defined by the (C u, X u, Y u ) mounting face, Z u being perpendicular to the mounting face and oriented towards the equipment. The origin is placed at a corner of the box, on a mechanical fixation point so that all other fixation points are in the +Y u /+Z u quadrant. 4.2 UNIT SYSTEM All dimensions in geometrical models shall be expressed in meters (m). The thermal model shall use SI units, that is: Volumetric capacities in watts per Kelvin (W/K). Mass in kilograms (Kg). Temperatures in Celsius ( C). Power in watts (W). Time in seconds (s). Thermal capacities in joules per Kelvin (J/K). Radiative couplings in m². 4.3 REFERENCE CASE In order to compare models in identical conditions, models and output files shall be delivered for specified reference cases. These reference cases can be different from the extreme thermal cases of the system concerned. For GAIA this case shall be HOT1 (steady-state), see section DELIVERABLE DOCUMENTATION At the delivery, each model shall be accompanied by a Mathematical Model report encompassing all TMM and GMM aspects. The thermal analysis results of the detailed analysis shall be reported in another document; Thermal Analysis Report.

15 Page 15 of 28 In addition a change record sheet containing the description of the changes has to be delivered. 4.5 THERMAL LOAD CASE DEFINITION The table below lists the load case parameters for thermal analyses: Case Thermo-opt. properties DSA Config. Solstice Solar Constant Earth IR Emission Albedo Factor HOT1 EOL Deployed Winter 1388 W/m² N/A N/A COLD1 BOL Deployed Summer 1293 W/m² N/A N/A STOWED BOL Stowed Dec W/m² 247 W/m² 0.41 TRANSFER BOL Deployed Start at Dec = f(t) = f(t) = f(t) Table 4-1: Summary of Load Case Parameters The "Solar Constant," the radiation that falls on a unit area of surface normal to the line from the Sun, per unit time, and outside of the atmosphere, at 1 AU has the standard value of 1367 ± 10 W/m², allowing for measurement uncertainties.

16 Page 16 of GEOMETRICAL MODEL SPECIFIC REQUIREMENTS 5.1 ELEMENT REPRESENTATION Each geometrical model shall form a completely enclosed surface (i.e. no unintentional spaces between shells). With detailed modelling there may be small gaps between structural elements (e.g. an equipment baseplate mounted onto the spacecraft surface). To reduce the amount of unnecessary detailed shell modelling the gap may be omitted with the corresponding radiative coupling directly implemented in the ESATAN thermal model. Geometrical mathematical models shall have a limited number of SHELLS. The maximum numbers of allowable shapes for each model are 4000 (TBC). 5.2 THERMO-OPTICAL PROPERTIES OF MATERIALS Thermo-optical properties shall be defined through materials. These materials shall be referenced at the geometrical shell definition. Thermo-optical properties should not be created within geometrical shapes. The names of materials referenced at the creation of geometrical shapes shall be generic. That is not dated, beginning of life or end of life. This enables the same geometrical definition for different model cases and stages of analysis. Assignment of the correct thermal optical properties, according to the case, shall be done by the assignment of each dated material to the generic one. The names of the material thermo-optical properties shall have the following format: PP_AAAAAATTT_suf where: PP identifies the project concerned; here GA for GAIA. AAAAAA identifies the material; for example: CHM309. TTT represents the material thickness: 15M=15mil, 2M5=2.5mil, 0M3=0.3 mil, TTT is used when the thickness is not applicable. suf stands for the property age; this suffix is only used for ESARAD, to define dated materials before re-utilisation by generic ones. Code BOL EOL FIX Description Beginning of life (also used for the internal coatings, non-damaged since they are not subjected to the external environment (sun, radiation, particles). End of life Coating not damaged by the external environment (for instance, metal laying). Table 5-1: Code of ESARAD Material Name Suffixes The following table, which is free for completion, lists the thermo-optical properties and the name w.r.t. the specified name for several materials:

17 Page 17 of 28 MATERIAL AND NAME IDEAL BLACK BODY (1) GA_BLACKBODY_INT ABSORPTANCE UV DIFFUSE UV SPECULAR UV TRANSMISSIVITY UV INT 1.0 EMITTANCE IR DIFFUSE IR SPECULAR IR TRANSMISSIVITY IR INT 1.0 ITO Aluminised Kapton 1 mil GA_KAPTON1M0_XXX ABSORPTANCE UV DIFFUSE UV SPECULAR UV TRANSMISSIVITY UV BOL DEGRADED_11Y EMITTANCE IR DIFFUSE IR SPECULAR IR TRANSMISSIVITY IR BOL to 11Y ITO Aluminised Kapton 2 mil GA_KAPTON2M0_XXX ABSORPTANCE UV DIFFUSE UV SPECULAR UV TRANSMISSIVITY UV BOL DEGRADED_11Y EMITTANCE IR DIFFUSE IR SPECULAR IR TRANSMISSIVITY IR BOL to 11Y ITO Aluminised Kapton 3 mil GA_KAPTON3M0_XXX ABSORPTANCE UV DIFFUSE UV SPECULAR UV TRANSMISSIVITY UV BOL DEGRADED_11Y EMITTANCE IR DIFFUSE IR SPECULAR IR TRANSMISSIVITY IR BOL to 11Y mil Second Surface Silver Teflon Tape GA_AGTEFL2M0_XXX BOL DEGRADED_11Y ABSORPTANCE UV EMITTANCE IR DIFFUSE UV 2 2 DIFFUSE IR SPECULAR UV SPECULAR IR TRANSMISSIVITY UV TRANSMISSIVITY IR BOL to 11Y mil ITO SiOx VDA Kapton VDA Tape GA_ACPFSOTTT_XXX BOL DEGRADED_11Y ABSORPTANCE UV DIFFUSE UV SPECULAR UV TRANSMISSIVITY UV BOL to 11Y EMITTANCE IR 0.26 DIFFUSE IR 0.74 SPECULAR IR TRANSMISSIVITY IR 2 mil Second Surface VDA Teflon Tape GA_ALFEP2MIL_XXX BOL DEGRADED_11Y BOL to 11Y ABSORPTANCE UV EMITTANCE IR 0.6 DIFFUSE UV 4 4 DIFFUSE IR 1 SPECULAR UV SPECULAR IR 0.39 TRANSMISSIVITY UV TRANSMISSIVITY IR

18 Page 18 of 28 MATERIAL AND NAME 5 mil silvered FEP Teflon GA_AGTEFL5M0_XXX ABSORPTANCE UV DIFFUSE UV SPECULAR UV TRANSMISSIVITY UV BOL DEGRADED_11Y EMITTANCE IR DIFFUSE IR SPECULAR IR TRANSMISSIVITY IR BOL to 11Y mil Aluminised FEP Teflon GA_ALTEFL2M0_XXX ABSORPTANCE UV DIFFUSE UV SPECULAR UV TRANSMISSIVITY UV BOL DEGRADED_11Y EMITTANCE IR DIFFUSE IR SPECULAR IR TRANSMISSIVITY IR BOL to 11Y OCLI Second Surface Quartz mirror (OSR) GA_OCLOSRTTT_XXX BOL DEGRADED_11Y ABSORPTANCE UV EMITTANCE IR DIFFUSE UV 1 1 DIFFUSE IR SPECULAR UV SPECULAR IR TRANSMISSIVITY UV TRANSMISSIVITY IR BOL to 11Y Aluminised Kapton Tape - External Surfaces GA_EXTVDATTT_XXX BOL DEGRADED_11Y ABSORPTANCE UV EMITTANCE IR DIFFUSE UV 5 5 DIFFUSE IR SPECULAR UV SPECULAR IR TRANSMISSIVITY UV TRANSMISSIVITY IR BOL to 11Y Aluminium Tape GA_ALTAPETTT_XXX ABSORPTANCE UV DIFFUSE UV SPECULAR UV TRANSMISSIVITY UV BOL DEGRADED_11Y EMITTANCE IR DIFFUSE IR SPECULAR IR TRANSMISSIVITY IR BOL to 11Y GSFC Cond. White Paint NS-43-C GA_GSFCWPTTT_XXX ABSORPTANCE UV DIFFUSE UV SPECULAR UV TRANSMISSIVITY UV BOL DEGRADED_11Y EMITTANCE IR DIFFUSE IR SPECULAR IR TRANSMISSIVITY IR BOL to 11Y Black Paint CHEMGLAZE Z306 (2) GA_CHM306TTT_XXX ABSORPTANCE UV DIFFUSE UV SPECULAR UV TRANSMISSIVITY UV BOL DEGRADED_11Y EMITTANCE IR DIFFUSE IR SPECULAR IR TRANSMISSIVITY IR BOL to 11Y Table 5-2: Thermo-optical properties

19 Page 19 of ADDITIONAL PROCESSING TO OBTAIN ESATAN INPUT Any automated or manual processing necessary to obtain the correct ESATAN input from the raw radiative software output shall be described in the documentation. Removal of GRs with specific nodes and surface trimming through coefficients are examples of this type of manipulation.

20 Page 20 of THERMAL MODEL SPECIFIC REQUIREMENTS 6.1 ELEMENT REPRESENTATION The thermal model shall concentrate on the accurate representation of interfaces. The external MLI layer shall be modelled separately from the structure underneath. Each external node of the thermal model shall correspond with one or several surfaces of the geometrical model. The thermal models shall be limited in size. The maximum number of nodes that can be used for each model is 1000 (TBC). The node numbering shall be in accordance to Table 6-1. Node Number Range Description Service Module Thermal Tent PLM Sun Shield Inactive Nodes Deep Space Table 6-1: Node Number Ranges used for GAIA Radiative couplings between the sub-models are covered by the ESARAD calculation using the main model. The conductive interface nodes between the sub-models are defined as arithmetic nodes (i.e. without thermal heat capacity) in Esatan. They are listed in Table 6-2. I/F Node Numbers Description 2991, 2992, 2993 I/F between SVM (top floor) and PLM (bipods) I/F between SVM (top floor) and PLM (MLI tent), number of nodes is TBD by EF I/F between SVM and DSA I/F between PLM and DSA (stowed configuration) at thermal tent Table 6-2: Definition of conductive interface nodes 6.2 MODEL MONITORING LOGIC The organisational philosophy is to use only one generic thermal model file to monitor all cases. External data, radiative and flux, are called with the $INCLUDE statement and the configuration definition is achieved using control variables. An application skeleton that enables the monitoring of the different run cases (see section ) is defined. The parameter values that allow the complete specification of the execution run are provided in the param.inp file. This is called either with an $INCLUDE statement or through the use of FORTRAN OPEN/READ/CLOSE commands. The advantage of the latter method is that the code does not need to be re-complied and re-loaded every time an input parameter is altered. The necessary parameters are global variables, but also consist of ESATAN control constants as indicated in Table 6-3. The items in normal type in Table 6-3 shall be used. The items in italics are recommended to be used as shown.

21 Page 21 of 28 Parameter Type Description RUNTYP Integer Specifies the type of run to execute: -1: Transient run execution from initial temperatures defined in an ESATAN formatted file called with $INCLUDE (steady state case). 0: Steady state + transient run. 1: Steady state run alone. DISSIP Integer Specifies the configuration to be used (in particular regarding dissipations). HEATCONF Integer Type of heating used in PLM (TBC) Table 6-3: Modelling Control Parameters 6.3 COUPLINGS The model couplings shall be structured according to the following: Internal structure couplings (structure, equipment to structure, MLI) Interface couplings with sub-models Internal radiative couplings, per enclosure. External radiative couplings. 6.4 TRANSIENT SENSITIVITY ANALYSES The main thermal calculations will be based on steady-state analyses. In addition several transient sensitivity analyses shall be performed, such as Variation of the solar incident caused by changes in satellite attitude (alpha = 0.2, beta = 0.4, 1 turn / 6 hours). This will be taken into account in ESATAN by a time dependent factor for the solar absorbed fluxes (ranging from to 1.004). Dissipation variation (±0.2% on a period of 6 hours). These sensitivity analyses shall be based on HOT1 (see section 4.5 ). 6.5 PROGRAMMING STANDARDS In order to make the model simpler to understand, the model code shall be structured as a series of subroutines, which are called by the $INCLUDE statement The model code shall either use ESATAN control variables and model global variables, or subroutine calls only. The intention is to reduce each $ section code to less than 30 (TBC) lines. An exemplary skeleton file for the flight calculations is shown in Appendix 1, which shall act as a guideline. The skeleton files corresponding to the launch phase or test campaign will show additional INCLUDE statements taking into account the changed environment (thermal nodes, interfaces, couplings).

22 Page 22 of MODEL ACCEPTANCE The Mathematical Model delivery acceptance criteria shall be: 7.1 THERMAL MODEL ACCEPTANCE Run of delivered reference cases (HOT Case) Comparison between the stand-alone model results generated in steady state mode and the main model results delivered. The mean of the deviations shall be less than 0.1 C (TBC) and the maximum deviation less than 1.0 C (TBC). 7.2 GEOMETRICAL MODEL ACCEPTANCE Run of the reference cases delivered. Run of the necessary processes that are specified in the model documentation, to obtain the correct ESATAN input data. Run of ESATAN models with this new data.

23 Page 23 of 28 APPENDIX 1 ESATAN SKELETON FILE $MODEL SKLT Name : Generic skeleton TMM Version : sklt.esa V1.0 03/05/01 Software: ESATAN Author : xxxx, Astrium-FN Case : Generic NAME DATE CHANGES $NODES $INCLUDE "sklt_nds.esa" Import of sub-models, interface and inactive nodes... B9999 = 'DEEP SPACE NODE', T=-27; $CONDUCTORS $INCLUDE "sklt_cpl.esa" Import of conductive sub-model couplings $INCLUDE "sklt_ifc.esa" Import of counductive interface couplings RADIATIVE CONDUCTORS $INCLUDE "sklt_int.esa" Import of internal radiative couplings (sub-models) $INCLUDE "sklt_igr.esa" Import of external radiative couplings (main model) $CONSTANTS $INTEGER Global Switching Logic: ITRAN = 0; Transient / Steady-State DISSIP = 0; Unit Operation and Dissipation HEATCONF = 0; Heater Power Modes RUNTYP = 0; run sequence (steady-state, Steady-state + transient, transient from initial temperature set...

24 Page 24 of 28 $REAL... $CHARACTER... $CONTROL TYPICAL VALUES SHALL BE MODIFIED TO ENSURE MODEL CONVERGENCE Thermal Control Constants: STEFAN = D-08 ; TABS = ; Global Solution Constants: RELXCA = 01 ; NLOOP = 3000 ; Transient Solution Constants: OUTINT = ; DTIMEI = 01 ; DTMIN = 001; DTMAX = 6 ; DTPMAX = 1 ; DAMPT = 1.0 ; $ARRAYS external heat input arrays $INCLUDE "sklt_eqa.esa" Import of transient flux tables (main model)... $SUBROUTINES SUBROUTINE QIAVE internal dissipation steady-state... RETURN END SUBROUTINE QICYCL internal dissipation transient... RETURN END SUBROUTINE QRAVE heating steady-state... RETURN END SUBROUTINE QRCYCL heating transient

25 Page 25 of RETURN END interpolation routines for external heat input $INCLUDE "sklt_eqi.esa" Import of transient flux subroutines (main model)... RETURN END $INITIAL $VARIABLES1 External Heat Fluxes, heating, internal dissipation IF (ITRAN.EQ. 1) THEN steady-state CALL QIAVG CALL QRAVG CALL QAVERG averaged external heat fluxes (main model) ELSE IF (ITRAN.EQ. 2) THEN transient CALL QICYCL CALL QRCYCL CALL QCYCLC transient external heat fluxes (main model) ELSE CONTINUE END IF undefined state $VARIABLES2 start of run IF (TIMEN.LT.1D0) THEN DTMAX = 1.0D0 DTMIN = 01D0 ENDIF $EXECUTION Open and read in the input parameters from file param.inp OPEN (99,FILE= param.inp, STATUS= OLD ) the case parameters values are in file param.inp to be included: READ (99, (/9X,I20) ) RUNTYP READ (99, (9X,I20) ) DISSIP READ (99, (9X,I20) ) HEATCONF RUNTYP: run type (Ignores first line of param.inp) DISSIP : configuration / dissipation mode HEATCONF : heater mode

26 Page 26 of 28 load a set of initial temperatures, if any exists (the file can be empty) $INCLUDE tempmod.tinit IF (RUNTYP.GE. 0) THEN CALL SOLVFM IF (RUNTYP.EQ.1) THEN WRITE (*,*) 'Run stopped after steady-state ' STOP END IF ELSE WRITE (*,*) 'No steady state run performed.' END IF ITRAN=2 transient CALL SLFWBK ENDIF $OUTPUTS IF (DISSIP.EQ.1) THEN HEADER='********** NOMINAL OPERATING MODE : HOT CASE *************' ELSE IF (DISSIP.EQ.2) THEN HEADER='********** MNOMINAL OPERATING MODE : COLD CASE *************'... ENDIF TFORM='(8X,I5,4X,A24,1X,7F10.3)' THEAD=' NODE LABEL T '// & ' C QI QS QA QE QR' IF(MODULE.EQ.'SOLVIT')THEN CALL PRNDTB(' ','L,T,C,QI,QS,QA,QE,QR',CURRENT) CALL PRNPER(NODES,T,QI,QA,QS,QE,QR,NNUM,NLAB) ELSE transient IF (PRNTRN.EQ.1) THEN CALL PRNDTB(' ','L,T,C,QI,QS,QA,QE,QR',CURRENT) CALL PRNPER(NODES,T,QI,QA,QS,QE,QR,NNUM,NLAB) ENDIF ENDIF $ENDMODEL SKLT

27 Page 27 of 28 DOCUMENT CHANGE LOG Issue/ Revision Date Modification Nb Modified pages Observations 1/00 17/03/2006 all Initial issue

28 Page 28 of 28 DOCUMENT CHANGE DETAILS ISSUE CHANGE AUTHORITY CLASS RELEVANT INFORMATION/INSTRUCTIONS A - - Initial Issue DISTRIBUTION LIST INTERNAL Lebranchu, Christian, EADS Astrium Rauscher, Ulrich, EADS Astrium Kerner, Rudi, EADS Astrium Schelke, Markus, EADS Astrium EXTERNAL ESA All Subcontractors, who shall deliver thermal models The copyright in this document is the property of EADS ASTRIUM GmbH and the contents may not be