欢迎来到天天文库
浏览记录
ID:40878879
大小:2.48 MB
页数:154页
时间:2019-08-09
《Analysis of Three Dimensional Dynamic Stall》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、AnalysisofThree-DimensionalDynamicStallAntonellaFerrecchiaThesissubmittedtotheFacultyofEngineering,UniversityofGlasgow,fortheDe-greeofDoctorofPhilosophy.Allaspectsoftheworkpresentedhereinareoriginalinconceptwhereindicated.TheresearchwasconductedbetweenOctober1997andOctober2000attheDe-partmentofAeros
2、paceEngineering,UniversityofGlasgow.AntonellaFerrecchia,December2000c2000AntonellaFerrecchiaAbstractThepurposeofthisworkistoenhancetheunderstandingofthedynamicstallpro-cessinboththetwodimensionalandthree-dimensionalcasesandtondoutwhataectsthedevelopmentandgrowthoftheleadingedgevortexassociatedwith
3、thephenomenonofstall.Inherentinthis,thestudyinvolvedtheanalysisofunsteadypressuredatarecordedalongthechordoftestmodelsundergoingaconstantrateramp-upmotion.Thisinvestigation,supportedby owvisualizationtestspointedoutthemainfeaturesofthedynamicstallvortexbehaviouralongthewingspanonbotharectangularanda
4、swepttipwing.Acomparisonoftheaerodynamicfeaturesoftheunsteady owatlocalcross-sectionsofbothwingswiththoseovertheNACA0015aerofoilshowedqualitativesimilarityofthestallprocessinboththetwodimensionalandthreedimensionalcasesandsingledouttheeectsofthewingspangeometry.Further,thedynamicstallvorticalstruct
5、ureattheleadingedgecouldbeattributedtoalocalvorticityaccumulation.Thevorticity uxwasexaminedtoidentifythemechanismsthatplaykeyrolesintheinitiationanddevelopmentofthevortex.Itwasfoundthatthe uxofvorticityfromthesurfaceoriginatedprimarilyfromtwoconcentratedregionsorsources.Thebehaviourofvorticity uxfr
6、omthesesourceswasrelatedtotheinteractingmechanismresponsibleforthedevelopmentofthe oweld.Moreover,theinvestigationsuggestedthatthevorticity uxisapracticaliiengineeringtooltopredicttheonsetofthestall.Inaddition,thechangesofthepressureandsurfacevorticity uxvariationsduetochangesinthereducedpitchratew
7、erealsocharacterized.Thelastpartoftheresearchfocussedonaninvestigationofdynamicstallvortexconvectionoverbothtwo-dimensionalandthreedimensionalaerodynamicsurfaces.Fromtheanalysisofthedynamicstallvortex
此文档下载收益归作者所有