Parametric Design, Aerodynamic Analysis and Parametric Optimization of a Solar UAV Aerospace ... PDF
Preview Parametric Design, Aerodynamic Analysis and Parametric Optimization of a Solar UAV Aerospace ...
Parametric Design, Aerodynamic Analysis and Parametric Optimization of a Solar UAV Nuno Miguel António Silva Thesis to obtain the Master of Science Degree in Aerospace Engineering Supervisors: Professor André Calado Marta and Doctor José Manuel da Silva Chaves Ribeiro Pereira Examination Committee Chairperson: Professor Fernando José Parracho Lau Supervisor: Professor André Calado Marta Member of the Committee: Professor Filipe Szolnoky Ramos Pinto Cunha June 2014 ii Tomyparents. Fortheirloveandsupport. iii iv Acknowledgments Mymostsincerethanksto: First and foremost, my supervisors Professor Andre´ Calado Marta and Dr. Jose´ Manuel da Silva Chaves Ribeiro Pereira for their patience, guidance and support throughout the period it took me to completethisthesis. LASEFfortheuseofitsinstallationsandresources. The LASEF team that relentlessly helped me when any technical adversities occurred when using theirequipmentinordertoperformalltheaerodynamicsimulations. Myfamilyandfriendsfortheirconstantsupportandbeliefinmethroughtheyears. v vi Resumo OobjectivodestatesefoidesenvolverumaferramentaCADquefac¸ausodescriptsporformaadesen- har diferentes configurac¸o˜es de UAVs e a posterior ana´lise aerodinaˆmica dessas configurac¸o˜es. Com recurso ao Star-CCM+ analisou-se um UAV em particular. O UAV de estudo consiste num Long En- duranceElectricUAV(LEEUAV).OLEEUAV,foisubmetidoaumase´riedeestudosaerodinaˆmicosonde se usou os modelos de turbuleˆncia Spalart-Allmaras e k−ω SST, este u´ltimo usado em conjunto com o modelo de transic¸a˜o γ −Re , e os seus resultados comparados com dados experimentais. Apenas θ o modelo de turbuleˆncia k −ω SST em conjunto com o modelo de transic¸a˜o γ −Re foram usados θ nas simulac¸o˜es aerodinaˆmicas mais detalhadas. Em voo cruzeiro, o LEEUAV apresenta uma raza˜o de finesse de 14.01, velocidade de perda de 6.21 m/s e velocidade ma´xima em voo cruzeiro de 29.3 m/s. Para melhorar a performance do LEEUAV implementaram-se estudos parame´tricos a` forma do nariz, asa e fuselagem. Com a modificac¸a˜o da forma do nariz, os gradientes de pressa˜o adversos a´ı localizados foram eliminados ou diminu´ıdos. Com a ponta da asa arredondada reduziu-se em 3 cm as bolhas de separac¸a˜o laminares na asa. Modificando a geometria da raiz da asa eliminou-se uma zonadeescoamentoseparadoquesegeravaapartirdos2o. Diminuindooaˆngulodeincideˆnciadaasa permitiu-seocontroloatrave´sdeaileronsate´ pelomenos10o. Palavras-chave: UAV Solar, Longo Alcance, Propulsa˜o H´ıbrida, CFD, CAD, Modelac¸a˜o Parame´trica,Ana´lisedeSensibilidade. vii viii Abstract Theaimofthisthesiswastodevelopandimplementacomputationalprocesstoenabletheswiftdesign ofdifferentUAVconfigurationsandtheiraerodynamicanalysis. Tothisend,aCADtoolusingscriptswas adoptedtodefinetheUAVexternalshapewhichwaslaterimportedintoaCFDtooltogeneratesuitable meshes. The test case consisted of a Long Endurance Electric UAV (LEEUAV), that was aerodynam- ically analyzed and parametrically optimized. While performing the aerodynamic analyses, turbulence modelsSpalart-Allmarasandk−ω SST,thelaterbeingemployedintandemwiththeγ−Re transition θ model,wereemployedandtheirpredictionscomparedwithexperimentaldata. Onlythek−ω SSTtur- bulencemodelandtheγ−Re transitionmodelwereemployedinthedetailedaerodynamicsimulations. θ During cruise, the baseline LEEUAV presents a lift-to-drag ratio of 14.01, stall speed of 6.21 m/s and maximumcruisespeedof29.3m/s. Toenhancethebaselinecruiseperformance,aseriesofparamet- ricoptimizationandsensitivitystudieswereperformedwhereitsnose, wingandfuselageshapeswere modified. With the nose shape modification proposal, the adverse pressure gradients that previously existed in that surface were reduced. With rounded wingtips, the wing long laminar separation bubbles werepredictedtodecrease. Withtheproposedwingrootfairing,aregionofseparatedflowthatformed beginning at 2o disappeared thus reducing the aircraft drag. With the proposed wing washout, aileron controleffectivenesswasextendedtoanglesofattackupto10o. Keywords: SolarUAV,UAVAirframe,LongEndurance,HybridPropulsion,ComputationalFluid Dynamics,Computer-AidedDesign,ParametricModeling,SensitivityAnalysis. ix x
Description:The list of books you might like
