LionSatLionSatThermal SubsystemThermal Subsystem

Team Members:Team Members:

Nathan HermansonNathan Hermanson

Adam McDonaldAdam McDonald

Joel ThakkerJoel Thakker

LionSat – Thermal Subsystem LionSat – Thermal Subsystem

ObjectiveObjective: maintain : maintain temperature within the temperature within the acceptable operating and acceptable operating and non-operating ranges non-operating ranges during the entire mission during the entire mission life of the program. life of the program.

Current designCurrent design: non-: non-insulated cylindrical insulated cylindrical Aluminum shell.Aluminum shell.

Allows for a good first Allows for a good first

approximationapproximation

Operating and Storage Temperatures

Overview

Problems and SolutionsProblems and Solutions Familiarization to the Familiarization to the

programprogram Software IssuesSoftware Issues- SINDA: Code was outdated and SINDA: Code was outdated and

not user friendly.not user friendly.- Thermal Desktop: Licenses not Thermal Desktop: Licenses not

available available - Working CAD model of LionSat Working CAD model of LionSat

with dimensions not available.with dimensions not available. Solutions:Solutions:- Downloaded trial version of Downloaded trial version of

Thermal DesktopThermal Desktop- Created our own 3D model Created our own 3D model

using Thermal Desktop; inner using Thermal Desktop; inner diameter of 18.5 inches and diameter of 18.5 inches and height of 18.31 inches. height of 18.31 inches.

Progress Made in Fall 2003Progress Made in Fall 2003 Single Node AnalysisSingle Node Analysis- Code written in MATLABCode written in MATLAB- Considered only two Considered only two

cases in orbitcases in orbit- Temperature ranges are Temperature ranges are

reasonablereasonable- Equivalent C++ code idea droppedEquivalent C++ code idea dropped Multi – Node AnalysisMulti – Node Analysis- Using Thermal Desktop onlyUsing Thermal Desktop only- Gives a good first approximation for heat flux Gives a good first approximation for heat flux

across the satellite at varying positions in orbitacross the satellite at varying positions in orbit

Input FormatInput Format

– – AutoCAD drawingsAutoCAD drawings

- Direct input can used in the trial version - Direct input can used in the trial version i.e. AutoCAD is not neededi.e. AutoCAD is not needed

- SolidWorks files can be imported by - SolidWorks files can be imported by AutoCAD using the plug-in ExchangeWorks. AutoCAD using the plug-in ExchangeWorks. This allows compatibility with the drawings This allows compatibility with the drawings done by the structures subsystem.done by the structures subsystem.

Uses finite analysis to model a thermal Uses finite analysis to model a thermal environment.environment.

Orbital parameters including altitude, inclination, Orbital parameters including altitude, inclination, and spin can be defined; and the thermal results and spin can be defined; and the thermal results due to earthshine, and solar radiation measured.due to earthshine, and solar radiation measured.

Heat sources and other radiation sources can be Heat sources and other radiation sources can be defined, and the conductivity throughout the defined, and the conductivity throughout the satellite can be observed.satellite can be observed.

Material properties can be defined and easily Material properties can be defined and easily changed.changed.

Thermal Desktop Material PropertiesThermal Desktop Material Properties

Top left: going into earth shadow; Top right: Complete Shadow; Bottom left: going into full sun; Bottom Right: Sun facing

Actual design of satellite exteriorNote: Few nodes on end caps.

This data can be used to determine the hot spots on the satellite where insulation may need to be applied.

Things to Prepare for the SDRThings to Prepare for the SDR

Each team was asked for any and all Each team was asked for any and all recent items in regard to five recent items in regard to five categories:categories:• Presentation slidesPresentation slides• Preliminary Subsystem DrawingsPreliminary Subsystem Drawings• Subsystem Test plansSubsystem Test plans• Materials ListMaterials List• Prototype HardwarePrototype Hardware

SDR (cont.)SDR (cont.)

The slides have been started, The slides have been started, currently working on revising them.currently working on revising them.

As the thermal subsystem is As the thermal subsystem is anticipated to be a fully passive one, anticipated to be a fully passive one, we do not have any preliminary we do not have any preliminary drawingsdrawings

Materials list will not be completed Materials list will not be completed until the multi-node analysis is until the multi-node analysis is completedcompleted

Work for Next SemesterWork for Next Semester

Ensure Thermal Desktop is available Ensure Thermal Desktop is available for LionSat Thermal Subsystemfor LionSat Thermal Subsystem

Finish simple multi-node analysisFinish simple multi-node analysis Develop a thermal budgetDevelop a thermal budget Begin incorporating all other Begin incorporating all other

subsystems into modelsubsystems into model Consider thermal vacuum testingConsider thermal vacuum testing

Questions?Questions?