Dynamic and Thermal Models for ECOSat-III Aerospace Engineering

119 Pages·2016·8.35 MB·English

by  Andre C. Marta

Dynamic and Thermal Models for ECOSat-III
Sofia de Fátima Caeiro Aboobakar
Thesis to obtain the Master of Science Degree in
Aerospace Engineering
Supervisor: Prof. Afzal Suleman
Examination Committee
Chairperson: Prof. Fernando José Parracho Lau
Supervisor: Prof. Afzal Suleman
Member of the Committee: Prof. Edgar Caetano Fernandes
November 2016
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Dedicatedtomyfamilywhoalwayssupportedmeduringthislongjourney.
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Acknowledgments
I would like to thank my supervisor Dr. Afzal Suleman for providing me the opportunity to develop
suchaninterestingworkinCentreforAerospaceResearchinUniversityofVictoriaandforthefinancial
support during my stay in Canada. I would like to thank the ECOSat team for providing me informa-
tion and for helping me whenever I needed. I would like to give a special thanks to two ECOSat team
members: CassHussmannforalltheorientationheprovidedduringthedevelopmentofmyworkandto
AbdulFourteiawhowasalwaysavailableandshowedhimselfveryhelpfulatalltimes. Iwouldalsolike
tothankStephenWarwickandPeterSherkfromCentreforAerospaceResearchinVictoriaInternational
AirportwhomanagedtoprovidemeaworkstationattheairportwithalltheresourcesIneededandfor
clarifyingmeonsomesubjectsofmywork. IwanttothankallthemembersoftheCentreforAerospace
Research, in both University of Victoria and Victoria International Airport, and of the ECOSat team for
thegoodtimesandamazingexperienceinCanada.
IwouldliketothankallmycolleaguesandprofessorsImetduringthisAerospaceEngineeringcourse
whohelpedmesurpassmylimitswhenIthoughtIcouldn’tmakeit. IalsothankmyTaekwondoprofes-
sor,colleaguesandstudents. Trainingdaysalwayshelpedmetorefreshmymindintimesofhardwork.
Last but not least, I would like to thank my mother, grandmother and brother for the unconditional
support during all my life. Your everyday support and the sacrifices made were essential to make this
dreamcometrue.
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Resumo
Lanc¸ar sate´lites para o´rbita e´ uma tarefa exigente do ponto de vista da manutenc¸a˜o da integridade
estruturaldacargatransportadapelolanc¸adoredopontodevistafinanceiro. Quandoe´ decididolanc¸ar
um sate´lite para o´rbita, o seu comportamento dinaˆmico e o seu perfil te´rmico durante a o´rbita teˆm de
sermantidosdentrodeumlimiteespec´ıficoparagarantirquena˜oha´ falhascausadasporumprojecto
estrutural e te´rmico inadequado. Modelos de elementos finitos sa˜o usados para prever o comporta-
mento da estrutura. Contudo, esses modelos devem ser validados por testes experimentais. Modelos
validados podem ser usados com confianc¸a para conduzir mais simulac¸o˜es que permitam avaliar o
comportamento do sate´lite e corrigi-lo se necessa´rio. Esta tarefa e´ mais dif´ıcil quando se lida com pe-
quenos sate´lites como o caso do ECOSat-III, um CubeSat de unidade tripla. Este trabalho descreve o
processo de avaliac¸a˜o do comportamento do sate´lite e de actualizac¸a˜o do seu modelo de elementos
finitosutilizandodadosexperimentais,semprequeposs´ıvel. Osrequisitosasersatisfeitosediscutidos
neste trabalho esta˜o relacionados com a frequeˆncia fundamental do sate´lite e a sua distribuic¸a˜o de
temperaturas. O objectivo desta tese e´ aumentar a frequeˆncia fundamental do nanosate´lite e permitir
que os seus componentes operem dentro da sua margem de temperaturas de seguranc¸a atrave´s do
desenvolvimentodeumsistemadecontrolote´rmico. Aavaliac¸a˜odasconsequeˆnciasdecadamudanc¸a
deprojectofoifeitaemostraquecomassoluc¸o˜espropostas,oECOSat-IIIesta´ prontoparaserlanc¸ado
esobrevivera`scondic¸o˜esdeambienteespacialemseguranc¸a,dopontodevistaestruturalete´rmico.
Palavras-chave:
Modelodeelementosfinitos,Actualizac¸a˜odomodelodeelementosfinitos,
Frequeˆnciafundamental,Sistemadecontrolote´rmico,CubeSat
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Abstract
Launchingasatelliteintoorbitisademandingtaskfromthepointofviewofmaintainingthelauncher’s
payload structural integrity and from the financial point of view. When it is decided to launch a satellite
into orbit, its dynamic behaviour and its thermal profile during its orbit have to be maintained within
specified levels to guarantee that no failure is caused by an inadequate structural and thermal design.
Finite element models are used to predict the structure’s behaviour. However, these models need to
be validated by experimental tests. Validated models can be used with reliability to perform further
simulationsthatallowtoproperlyevaluatethesatellite’sbehaviourandtocorrectitifneeded. Thistask
isharderwhendealingwithsmallsatellites,thecaseoftheECOSat-III,atriple-unitCubeSat. Thiswork
describestheprocessofevaluatingthebehaviourofthesatelliteandperformingitsfiniteelementmodel
update using experimental data, whenever possible. The requirements to be satisfied and discussed
in this work are related to the fundamental frequency of the satellite and its temperature distribution.
The objective of this thesis is to increase the fundamental frequency of the nanosatellite and to make
allitscomponentsoperateintheirsafetemperaturerangebydevelopingathermalcontrolsystem. The
evaluation of the consequences of each design change has been performed and shows that with the
proposed solutions, the ECOSat-III is ready to be launched and survive space environment conditions
safely,fromthestructuralandthermalpointofviews.
Keywords:
Finiteelementmodel,Finiteelementmodelupdate,Fundamentalfrequency,Ther-
malcontrolsystem,CubeSat
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