Flight dynamics and simulation of a generic aircraft for aeroservoelastic design Aerospace ...

116 Pages·2016·2.78 MB·English

by  Andre C. Marta

Flight dynamics and simulation of a generic aircraft for
aeroservoelastic design
Pedro Tomás Marques Martins Margarido
Thesis to obtain the Master of Science Degree in
Aerospace Engineering
Supervisor: Prof. André Calado Marta
Examination Committee
Chairperson: Prof. João Manuel Lage de Miranda Lemos
Supervisor: Prof. André Calado Marta
Member of the Committee: Prof. Agostinho Rui Alves da Fonseca
November 2016
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”Thedawnmistglowing,
Thewaterflowing,
Theendlessriver,
Foreverandever”
DavidGilmour
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Acknowledgments
The process of writing a dissertation is exhaustive and arduous - and it is certainly not done single-
handedly.
Iwanttothankmysupervisor,ProfessorAndre´ CaladoMarta. ThankyouProfessor,forallyourhelp,
support and specially enthusiasm. I believe that I am tremendously fortunate to have worked with an
outstandingscholarandexcellentperson.
I would like to thank my parents, Maria and Fernando that helped me become everyday a better
versionofmyself,andtotheirsacrificeanddedicationovermylife,Idedicatethemmybiggestachieve-
ment,theMaster’s. Astheoldestbrother,Iamalsodeeplythankfultomybrothers,LuisandIneˆs,whose
presenceenlightenedmeandmadememoreresponsiblethroughoutalltheseyears.
I am deeply grateful to my maternal grandparents, Angela and Joa˜o, who cared for me and played
animportantroleinthedevelopmentofmyidentityandshapingtheindividualthatIamtoday. Iwasalso
extremelyfortunateinmylifetohavepaternalgrandparentswhohaveshownmeunconditionalloveand
kindnessthroughtheirlife,andIamsorrythattheyarenotpresenttoseemegraduate.
ImustthankmygirlfriendSara,whogavemestrengthinthedayswhenIwasnotinmoodofwriting
or researching. Through her and her smile I found an easier path for concluding my Master’s, and for
thatIamentirelygrateful.
Finally, I want to thank all the friends I made throughout this five year journey. Their help and pres-
enceinspiredmetoreachthisgoalandwithoutthemitwouldhavebeencertainlybeentougher.
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Resumo
Com o mercado emergente do sector aerona´utico, comec¸a a aparecer a necessidade de ferramentas
que estudem o comportamento aeroservoelastico de uma aeronave. Existem modelos matema´ticos
paraesteestudo,pore´msa˜ocomplicadosemuitosdelesusamodom´ıniodafrequeˆncia.
Nesta dissertac¸a˜o foram desenvolvidas as equac¸o˜es de movimento aeroservoelasticas de uma
aeronavegeralparacondic¸o˜esdeequil´ıbrionodom´ıniodotempo. Foidesenvolvidoumprogramapro-
duzidoemC++queintegraestasmesmasequac¸o˜es,equenofuturopodera´ serinclu´ıdonoutrosprojec-
tos como uma pec¸a de conexa˜o entre diversas a´reas da aerona´utica, como aerodinaˆmica, dinaˆmicas
estruturais e controlo de voo. Para desenvolver esta ferramenta va´rios me´todos de integrac¸a˜o foram
inspecionadoseconsequentementeencontrandoautilidadedecadaum. Consequeˆnciasdaaeroelas-
ticidadeforamtambe´mdiscutidaseutilizadasparaintroduzirocontroloo´ptimo.
Foi tambe´m realizado um simulador de voo em MATLAB(cid:13)R utilizando controlo o´ptimo. O compor-
tamento do controlo o´ptimo, mais consequentemente o regulador quadra´tico linear, nas dinaˆmicas de
voofoitambe´mestudado. Estesimuladordevoopermitesimularomovimentodeumaaeronavegeral,
adoptandoumconjuntodederivadasaerodinaˆmicasdeaeronavesnaliteratura,emregimesturbulentos
e em casos de falha de motor em aeronaves com ate´ cinco motores. O estudo das simulac¸o˜es feito
nestadissertac¸a˜otevemaisemcontaqueaaeronaveconsigagarantirequil´ıbrioerumoemsituac¸o˜es
cr´ıticas,comoasacimareferidas.
Palavras-chave:
dinaˆmica de voo, controlo o´ptimo, aeroservoelasticidade, simulac¸a˜o de
voo,integrac¸a˜o
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Abstract
Theemergingmarketoftheaviationsectorbeginstorequesttheneedfortoolstostudytheaeroservoe-
lasticbehaviourofanaircraft. Therearemathematicalmodelsforthiskindofstudy,butitsinterpretation
isnoteasyandmanyusethefrequencydomain.
Inthisthesistheaeroservoelasticequationsofmotionofageneralaircraftforequilibriumconditions
in time domain were developed. A program was also developed, produced in C++(cid:13)R, which integrates
thesesameequations,andthatinthefuturemaybeincludedinotherprojectsasaninterconnectiontool
betweendifferentfieldsofaeronautics,suchasaerodynamics,structuraldynamicsandflightcontrol. To
develop this tool, various integration methods were inspected and consequently the utility of each one
wasfound. Aeroelasticityconsequenceswerealsodiscussedandusedtointroducetheoptimalcontrol.
It was also carried out a flight simulator in MATLAB(cid:13)R using optimal control. The optimal control
behaviour,morespecificallythelinearquadraticregulator,intheflightdynamicswasalsostudied. This
flightsimulatorallowsthesimulationofthemotionforageneralaircraft,adoptingasetofaerodynamics
derivatives of general aircraft from the literature, on turbulent air flows and in engine failure cases in
aircraftuptofiveengines. Thesimulationstudyinthisthesishadmoreinmindtoensurethattheaircraft
maintainsitsequilibriumandcourseincriticalsituations,asreferredabove.
Keywords:
flightdynamics,optimalcontrol,aeroservoelasticity,flightsimulation,integration
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