ASIM Thermal Mathematical Model

Part of WP 30-500 – ASIM Structural and Thermal Analysis.

MTR-meeting 13-06-2008

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WP 30.500 – Thermal Part at MTR.

Aim:- Compile all the, up to date, requirements and inputs.- Understand the thermal conditions of the payload.- Based on the understanding of thermal conditions

propose the first approximation of thermal design.- Check this proposed design for the different thermal

conditions in order to show the hurdles and limitations- Come with recommendations for the next phase design.- Extract the thermal parameters necessary for the

evaluation of the particular designs

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ASIM Thermal Mathematical Model – Input compilation

Mass budgets:

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ASIM Thermal Mathematical Model – Input compilation

Power:

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ASIM Thermal Mathematical Model – Input compilationTemperature Requirements

• [RD1] ASIM-TER-MMIA-REQ-003, Rev: 1 draft A ASIM MMIA Camera Head Unit Requirements Specification• [RD2] ASIM-TER-MMIA-REQ-005, Rev: 1 draft A ASIM MMIA DPU Requirement Spec.• [RD3] ASIM-TER-MMIA-REQ-004, Rev: 1 draft A ASIM MMIA Photometer Requirement Spec.

• [RD4] ASIM-UV-MXGS-REQ-002, Rev: 1 ASIM MXGS DPU Hardware Requirement Specification

• [RD9] ASIM-UB-MXGS-REQ-001, Rev: 2dA ASIM MXGS DFEE Requirements Specification

Min. Operational Temperature

Max. Operational Temperature

- 16 [ºC] +15 [ºC]

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ASIM Thermal Mathematical

Model – Input compilat.

Operational Modes

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ASIM Thermal Mathematical Model – Input compilationTransportation Modes

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ASIM Thermal Mathematical Model – AnalysisThermal Environment

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ASIM Thermal Mathematical Model – AnalysisThermal Environment- Cold Case

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ASIM Thermal Mathematical Model – Input compilation

Thermal Environment- Hot Case

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ASIM Thermal Mathematical Model – Analysis

Thermal Environment- Mean Case

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ASIM Thermal Mathematical Model – Analysis

Thermal Environment- Case β=±37.5º

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ASIM Thermal Mathematical Model – Model Build-upRadiator Concept – Proposal #1.

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ASIM Thermal Mathematical Model – Model Build-upTMM – 1-st Approximation.

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ASIM Thermal Mathematical Model – Model Build-upTMM – ASIM Part FEM Mesh

FEM model of ASIM build up of 2724 nodes and 2465 elements (mainly thin shell linear quadri-lateral elements and 12 beam elements)

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ASIM Thermal Mathematical Model – Model Build-up.Internal Radiation Enclosure

Internal Radiation enclosure comprising DPU, PDU, MXGS housing & collimator as well as the part of the one of the LIMB MMIAs surrounded by the radiators and MLI.

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ASIM Thermal Mathematical Model – Model Build-upTherm.- Boundary Conditions and - Couplings, Radiation and Orbit Modeling.

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ASIM Thermal Mathematical Model – Model Build-up

Material and Physical Properties

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ASIM Thermal Mathematical Model – Run and Run ControlView Factor Sums

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ASIM Thermal Mathematical Model – Run and Run ControlSolar View Factor – Cold Case

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ASIM Thermal Mathematical Model – Run and Run ControlEarth View Factor – Cold Case

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ASIM Thermal Mathematical Model – Run and Run ControlDifferent Factors – Cold Case

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ASIM Thermal Mathematical Model – Results

MXGS- Max. Min. and Avg. Temperatures

Case MXGS     MXGS      

  Collimator   Housing    

  Tmax Tmin ∆T Tavg. Tmax Tmin ∆T Tavg.

  [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC]

Hot case-Full Power 26,3 18,0 8,3 22,2 21,3 19,5 1,8 20,4

Hot case-MMIA OFF 20,8 12,5 8,3 16,7 13,0 11,0 2,0 12,0

Mean case –FullPower 12,9 -3,2 16,1 4,9 9,0 6,7 2,3 7,9

Mean case EclipseON 8,1 -7,0 15,1 0,6 4,2 1,1 3,1 2,7

Mean case –StandBy 7,0 -9,8 16,8 -1,4 1,8 -1,9 3,7 0,0

Mean case MMIA OFF 6,3 -10,0 16,3 -1,9 0,8 -2,8 3,6 -1,0

Cold case-Full Power -27,8 -30,5 2,7 -29,2 -25,6 -26,6 1,0 -26,1

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ASIM Thermal Mathematical Model – Results

MXGS- Max. Min. and Avg. Temperatures

Case MXGS     MXGS      

  Collimator   Housing    

  Tmax Tmin ∆T Tavg. Tmax Tmin ∆T Tavg.

  [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC]

Hot case-Full Power 26,3 18,0 8,3 22,2 21,3 19,5 1,8 20,4

Hot case-MMIA OFF 20,8 12,5 8,3 16,7 13,0 11,0 2,0 12,0

Mean case –FullPower 12,9 -3,2 16,1 4,9 9,0 6,7 2,3 7,9

Mean case EclipseON 8,1 -7,0 15,1 0,6 4,2 1,1 3,1 2,7

Mean case –StandBy 7,0 -9,8 16,8 -1,4 1,8 -1,9 3,7 0,0

Mean case MMIA OFF 6,3 -10,0 16,3 -1,9 0,8 -2,8 3,6 -1,0

Cold case-Full Power -27,8 -30,5 2,7 -29,2 -25,6 -26,6 1,0 -26,1

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ASIM Thermal Mathematical Model – ResultsMMIA#1 – Max. Min. and Avg. Temperatures

MMIA#1     MMIA#1     MMIA#1    

DFEE     DPU       Baffle    

Case Tmax Tmin ∆T Tavg. Tmax Tmin ∆T Tavg. Tmax Tmin ∆T Tavg.

Mode [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC]

Hot-FullP 27,5 23,5 4 25,5 35 30 5 32,5 27,5 -1 28,5 13,3

Hot-MMIA 8 4,9 3,1 6,45 12 7 5 9,5 23 -6 29 8,5

MeanFullP 20,5 12 8,5 16,3 29 18,5 18,5 23,8 43,5 -10 53,5 16,8

Mean-Eclips 10 2,5 7,5 6,25 14 7 7 10,5 41 -14 55 13,5

Mean-StandB 4 -6 10 -1 10 -3 13 3,5 39,8 -15 54,8 12,4

Mean-MMIA 2 -8,4 10,4 -3,2 5,7 -5,6 11,3 0,05 38,5 -15 53,7 11,7

Cold-Full -22 -22 0,4 -22 -16,5 -17 0,3 -16,7 -57 -67 9,8 -62

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ASIM Thermal Mathematical Model – Model Build-up

MMIA#2 – Max. Min. and Avg. Temperatures

MMIA#2     MMIA#2     MMIA#2    

DFEE     DP U      Baffle    

CaseTmax

Tmin ∆T Tavg.

Tmax

Tmin ∆T Tavg.

Tmax

Tmin ∆T Tavg.

Mode [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC]

Hot-FullP 32 26 5,8 29,1 34 25 9,5 29,3 38 7 31 22,7

Hot-MMIA 10 5 5 7,5 13 3 9,6 7,8 36 3,5 33 19,8

MeanFullP 29 14 15 21,5 32 14 18 23 41 -11 52 15

Mean-Eclips 14 3,5 10 8,55 15 3 12 9,2 39 -13 52 13

Mean-StandB 5,5 -813,

5 -1,3 12 -6 18 3 37 -15 52 11

Mean-MMIA 5 -10 15 -2,5 7 -12 19 -2,5 38 -15 53 11,3

Cold-Full -26 -27 0,4 -26 -24 -24 0,2 -23,8 -59 -61 2,2 -60

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ASIM Thermal Mathematical Model – ResultsMMIA#3 – Max. Min. and Avg. Temperatures

MMIA#3     MMIA#3     MMIA#3    

DFEE     DPU       Baffle    

Case Tmax Tmin ∆T Tavg. Tmax Tmin ∆T Tavg. Tmax Tmin ∆T Tavg.

Mode [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC]

Hot-FullP 28,2 26,9 1,3 27,6 25,3 23,9 1,4 24,6 36,2 22 14,2 29,1

Hot-MMIA 11 9,9 1,1 10,5 11,5 9,9 1,6 10,7 29 14 15 21,5

MeanFullP 25,8 13,8 12 19,8 22,5 11 11,5 16,8 20,8 1,8 19 11,3

Mean-Eclips 12,3 2,2 10,1 7,25 14,8 2 12,8 8,4 15,8 -3,2 19 6,3

Mean-StandB 6,6 -3,9 10,5 1,35 8,1 -3,9 12 2,1 12,7 -7,7 20,4 2,5

Mean-MMIA 7 -4,8 11,8 1,1 8,1 -4,7 12,8 1,7 12,2 -7,4 19,6 2,4

Cold-Full -21 -23 1,3 -22 -23,5 -24 0,8 -23,9 -11 -24 12,9 -18

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ASIM Thermal Mathematical Model – Results

DPU and PDU- Max. Min. and Avg. Temperatures

Case DPU     PDU    

Mode                

  Tmax Tmin ∆T Tavg. Tmax Tmin ∆T Tavg.

  [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC]

Hot-FullP 52 50 2 51 36 33 3 34,5

Hot-MMIA 44 42 2 43 25,5 23,3 2,2 24,4

MeanFullP 43 35 8 39 25,5 20 5,5 22,8

Mean-Eclips 37,7 29,3 8,4 33,5 20,7 15,3 5,4 18

Mean-StandB 34,5 25,6 8,9 30,1 16,3 9,3 7 12,8

Mean-MMIA 34 25,6 8,4 29,8 16,3 10,7 5,6 13,5

Cold-Full 9,9 9,85 0,05 9,88 -9,8 -9,9 0,1 -9,85

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ASIM Thermal Mathematical Model – Results

RAM, WAKE and ZENITH Radiators Temperatures

  RAM Radiator   Wake Radiator   Zenith Radiator  

Case                        

  Tmax Tmin ∆T Tavg. Tmax Tmin ∆T Tavg. Tmax Tmin ∆T Tavg.

  [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC] [ºC]

Hot-FullPower 9,8 6 3,8 7,9 16 8 8,4 12,2 3,7 3,2 0,5 3,5

Hot-MMIA Off -0,2 -2 1,8 -1,1 4,8 -5,2 10 -0,2 -3,6 -4,3 0,7 -4

MeanFull Power On 4,3 -8,2 12,5 -2 18 5 13 11,7 7 -18 25 -5,6

Mean-Eclipse on -0,8 -13,8 13 -7,3 13 -10 23 1,35 -7 -23 16 -15

Mean-StandBy -4 -18 14 -11 11 -21 31 -5 -11 -27 16 -19

Mean-MMIA off -5,3 -18,4 13,1 -12 9 -15 24 -3 -10 -26 16 -18

Cold-Full -38,5 -39,5 1 -39 -38 -38 0,3 -38 -48 -49 0,8 -48

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ASIM Thermal Mathematical Model - Conclusion

The first approximation ASIM TMM, presented here for the MTR, shows that it should be possible to design simple thermal system, without the louvers and other sophisticated solutions, able to dissipate the power of normal operational modes,

while satisfying the most of the temperature requirements of the payload. MMIA interval of [-10ºC; +10ºC]

defined as min. operational to optimal operational temp., should be revised or it should be accepted that during the exceptional thermal conditions this interval

could be temporarily overstepped. The same goes for MXGS’ DFEE where

the optimal operational interval of [-16ºC; +15ºC] could be overstepped for special non-normal operational modes.

With all the instruments constantly ON, dissipating its full power, the optimal operational temperature requirements are not fulfilled during almost all the orbits

with the tested design, optical material properties and thermal couplings.Further modeling work is required to address the number of questions not analyzed

yet or the one this TMM have shown to be critical. The mission scenario needs also to give the modeling work input on the number of

questions, e.g. power dissipation during aurora and earth observation modes or during non-nominal ISS’ pointing.

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ASIM Thermal Mathematical Model – ResultsTemperature Distribution- Hot Case

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ASIM Thermal Mathematical Model – Results