Thermal design
Download
1 / 28

Thermal Design - PowerPoint PPT Presentation


  • 145 Views
  • Uploaded on
  • Presentation posted in: General

Thermal Design. Christopher Smith RBSP Thermal Engineer Space Sciences Lab University of California, Berkeley. Outline. Requirements APL – UCB Interface Thermal Model Description IDPU Board Level Thermal Analysis Thermal Model Case Set Inputs Current Predicts Current Testing Overview.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

Thermal Design

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Thermal Design

Christopher Smith

RBSP Thermal Engineer

Space Sciences Lab

University of California, Berkeley


Outline

  • Requirements

  • APL – UCB Interface

  • Thermal Model Description

  • IDPU Board Level Thermal Analysis

  • Thermal Model Case Set Inputs

  • Current Predicts

  • Current Testing Overview


Spacecraft Level Thermal Requirements

  • Orbit: 500-675 km x 30,050 - 31,250 km (EFW-7, EFW-8)

  • Inclination: 10 degrees +/- 0.25 (EFW-6)

  • 2 year design life, plus 60 days (EFW-1)

  • Spacecraft top deck pointed to sun within: 25 degrees N/S and E/W, normal operation (EFW-201) 27 degrees composite, normal operation (EFW-202) 33 degrees, Safe mode (SCRD 3.10.4.4) (Was 47)

  • S/C spin rate (about top deck):

    4 to 6 RPM, normal and safe modes (EFW-9)

    3 to 15 RPM, instrument commissioning (EFW-203)

  • S/C shall survive 112 minute eclipse (Derived EFW-6, EFW-7, EFW-8)


EFW Thermal Requirements

  • Conductive external surfaces with 105 Ohms/Sq. (EFW-133)

  • Contamination: 100,000 class (EFW-132)

  • Instruments to operate within specification with -25 to +55 spacecraft boundary conditions. (EFW-76, EFW-77)

    • -25 to +65 for top deck interface, new since PDR

  • Instruments to survive without damage with -30 to +60 spacecraft boundary conditions. (EFW-79, EFW-80)

    • -30 to +70 for top deck interface, new since PDR

  • Comply with contamination control plan. APL document 7417-9007. (EFW-132)

  • Comply with Environmental Design and Test Requirements Document. APL document 7417-9019. (EFW-136)

  • Comply with RBSP_EFW_SYS_301_ETM, RBSP engineering test matrix


Engineering Test Matrix

  • 7 total cycles per instrument, 5 at component level, 2 at suite level.

  • Pre-Amps cycled separately due to larger temperature swing.

  • No need for thermal balance as all instruments are conductively coupled to the spacecraft.


APL Thermal Modeling Interface

  • Berkeley maintains a Thermal Desktop model of the EFW instrument and a boundary node definition of the spacecraft.

  • APL Maintains a TSS geometry and SINDA network model of the spacecraft.

  • APL integrates Berkeley geometry via Thermal Desktop TSS export.

    • Provides environmental heat flux data to instruments.

  • APL integrates Berkeley SINDA network model into the SINDA spacecraft network model.

    • APL specifies spacecraft connection nodes.

  • APL runs integrated model and provides temperature predicts back to Berkeley.

  • Design cycles as necessary.

  • APL is responsible for producing high fidelity temperature predicts.


Thermal Model OverviewInstruments and Boundary Spacecraft

IDPU

AXBs

SPBs


Thermal Model OverviewAXB -Stowed

Sphere / Preamp in Caging Mechanism

(Clear Alodine, GeBK Blanket)

Sphere / Preamp

(DAG 213)

Rod to Stacer Hinge

(DAG 213)

Mounting Tube (M55J)

Stacer

(Elgiloy)


Thermal Model OverviewAXB -Deployed

Stacer

(Elgiloy)

Sphere

(DAG 213)

DAD

(AntiSun: Clear Alodine)

(Sun: Clear Alodine / GeBk Tape mix)

Sphere Caging Mechanism

(AntiSun: Clear Alodine)

(Sun: GeBk Blanket / Clear Alodine mix)


Thermal Model OverviewSPB Deployed Elements

SPB Sphere

SPB Preamp

Thick Wire

Thin Wire


Thermal Model OverviewSPB & IDPU

SPB - Deployed

IDPU

(Mostly Black Kapton XC Tape, Some Gold Alodine)

(Black Kapton XC Tape)

(Clear Alodine)

SPB - Stowed

(Black Kapton Blanket, Shown in Green)


DCB Component Dissipations


DFB Component Dissipations


LVPS Component Dissipations


LVPS Board Distribution


Optical Materials

  • Most properties tested, used, and correlated for the THEMIS mission

  • Properties approved by the GSFC coatings committee July 07, 2008.


Thermophysical Properties

  • Hot Cases Use Low e* Anti-Sunward and High e* Sunward

  • Cold Cases Use High e* Anti-Sunward and Low e* Sunward


Interfaces

IDPU

  • Conductively mounted to spacecraft side panel.

  • 9 #10 Bolts = 0.75 W/C each.

  • Radiative coupling to spacecraft interior, Black Kapton XCTape

    SPB

  • Conductively mounted to spacecraft side panel.

  • 4 #10 Bolts = 0.75 W/C each.

  • Deployed elements are completely isolated from the spacecraft by wire.

  • Low radiative coupling to spacecraft interior, Clear Alodined Aluminum

    AXB

  • Conductively mounted to the top and bottom spacecraft deck.

  • 6 #8 Bolts at each end = 0.75 W/C each.

  • Radiative coupling somewhat isolated from major portions of the spacecraft since the mechanical units are stowed inside a carbon fiber tube which is also stored inside a spacecraft carbon fiber tube.

  • Deployed elements are isolated from spacecraft influence by stacer.

  • Caging mechanisms conductively mounted to top deck, 4 #8 Bolts = 0.75 W/C each.


Power, Heaters

  • Current power used in model

  • IDPU, SPB and AXB do not have any survival heaters


General Case Sets

APL Case Set Parameters

UCB Case Set Parameters


Limit Categories

  • Science Operation Limit

    • Limits placed on an operating instrument

    • Specifies the range of temperatures the instrument will provide calibrated / useful science data

  • Operation – Out of Spec

    • Limits placed on an operating instrument

    • May represent a wider range that is survivable but may be out of spec

    • Temperatures beyond Science Op Limit need not be calibrated to

  • Non-Operation

    • Limits placed on a non operating instrument

  • Pre-Deployment Limit

    • Limits placed on a mechanical system before it is actuated

  • Deployment Limit

    • Limits placed on a mechanical system at the time of actuation

  • Post-Deployment Limit

    • Limits placed on a mechanical system after it has executed its one-time deployment


Current Thermal Limits


Predicts, Deployed Case Sets


Margins, Deployed Case Sets

  • Positive Margins for all deployed cases


APL and UCB Predict Comparison, Table

  • Each case set compared at a specific time and a representative node

  • All case sets agree to within 1.5 degrees


APL and UCB Predict Comparison, Plot


ETU Thermal Vac Testing Completed


This page intentionally almost blank


ad
  • Login