Designing Active Control Laws in a Computational Aeroelasticity(PhD)

《Designing Active Control Laws in a Computational Aeroelasticity(PhD)》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、DesigningActiveControlLawsinaComputationalAeroelasticityEnvironmentJerryR.NewsomDissertationsubmittedtotheFacultyoftheVirginiaPolytechnicInstituteandStateUniversityinpartialfulfillmentoftherequirementforthedegreeofDoctorofPhilosophyinMechanicalEngineeringDr.HarryS.Robertsh

2、aw,Co-ChairDr.RakeshK.Kapania,Co-ChairDr.MichaelW.HyerDr.DanielJ.InmanDr.DonaldJ.LeoApril11,2002Blacksburg,VirginiaKeywords:Aeroelasticity,ComputationalFluidDynamics,FlutterActiveControlsDesigningActiveControlLawsinaComputationalAeroelasticityEnvironmentJerryR.Newsom(ABSTR

3、ACT)Thepurposeofthisdissertationistodevelopamethodologyfordesigningactivecontrollawsinacomputationalaeroelasticityenvironment.Themethodologyinvolvesemployingasystemsidentificationtechniquetodevelopanexplicitstate-spacemodelforcontrollawdesignfromtheoutputofacomputationalae

4、roelasticitycode.Theparticularcomputationalaeroelasticitycodeemployedinthisdissertationsolvesthetransonicsmalldisturbanceequationusingatime-accurate,finite-differencescheme.Linearstructuraldynamicsequationsareintegratedsimultaneouslywiththecomputationalfluiddynamicsequatio

5、nstodeterminethetimeresponsesofthestructuraloutputs.ThesestructuraloutputsareemployedastheinputtoamodernsystemsidentificationtechniquethatdeterminestheMarkovparametersofan“equivalentlinearsystem”.Theeigensystemrealizationalgorithmisthenemployedtodevelopanexplicitstate-spac

6、emodeloftheequivalentlinearsystem.Althoughtherearemanycontrollawdesigntechniquesavailable,thestandardLinearQuadraticGuassiantechniqueisemployedinthisdissertation.Thecomputationalaeroelasticitycodeismodifiedtoacceptcontrollawsandperformclosed-loopsimulations.Fluttercontrolo

7、farectangularwingmodelischosentodemonstratethemethodology.Variouscasesareusedtoillustratetheusefulnessofthemethodologyasthenonlinearityofthecomputationalfluiddynamicssystemisincreasedthroughincreasedangle-of-attackchanges.DedicationTomywife,Ellen,thankyouandIloveyou.iiiAck

8、nowledgementsFirst,IwanttothanktheNASALaRCforgivingmethetimeandsupporttoconductthisresear