圓柱可壓縮繞流及其流動(dòng)控制的大渦模擬研究.pdf

1、中國(guó)科學(xué)技術(shù)大學(xué)博士學(xué)位論文圓柱可壓縮繞流及其流動(dòng)控制的大渦模擬研究姓名：許常悅申請(qǐng)學(xué)位級(jí)別：博士專(zhuān)業(yè)：流體力學(xué)指導(dǎo)教師：陸夕云20090501AbstractAbstractThecompressible丑owpastablu8bodyisofimportanceinfundamentalsandapplicationsTherelevant、^，orkhausbeenstudiedusiI堰largeeddysimula土ionin

2、thisdisserta土ionInthepresentstudy，thethreedimensionalFhvre—nlteredcompressibleNavierStokesequatioIlsaresolvedbymeansofafinite—volumemethodThreetypicalcaSes，includingtrallSonicBawpastacircularcylinderwlthdi矗erentfree—stre

3、amMa血眥mbers，the丑owpastawaVycylinder，andtheflowpastacircularcylinderwithtabs，areinvestigatedindetailTheresultsandconclusionsaredescribedbrie丑yasfol】ows：(1)(2)E&ctofthefreestreamMachIlumberM0ontransonicflowpastacircularcyl

4、inderhasbeenirl、restigatedI沁sultsshowthatthereexisttwDflowstatesdependentonacriticalMachnumber』愎：rOneisanunsteadynowstateforM。o^結(jié)Basedoncarefullyexaminingthe丑owev01utionforboththe丑owstates，10calsupersoniczonesareident邁ed

5、inthenearwakeandgeneratedbyt、∞typicmprocesses，ie，vortex／vortexinteractionandshockwave／vortexinteractionIntheun_steadyflowregime，theconvectiveMachnumber^厶ofturbulentshearlayersisidentifiednearlyas』愎1，andtheinstaLbilitypro

6、cessismainlyrelatedtobidimensionaIonewiththespanwiserollingeddiesoriginatingfromtheKeiVin—HelmholtzinstabilityInthequasisteady丑owre百me，、ve6ndthat^幺≥1andobliquemodesdominatetheshearlayerinstabilityprocessThetransonicnowpa

7、stawavycylinderhaLsbeeninvestigatedtoanalyzetheflowcontr01behaviorsComparingwiththeforcesexertedonthewavycylinderandcircularcylinder，itisfbundthatadragreductionisobtainedandliftoscillationonthewavyeylinderisgreatlysuppre

8、ssedBaSedonanal”jsofthe丑owstructures，turbulencecharacteristics，vortexdynamics，andinstabilityofshearlayersintheflowfleld，thecontrolmechanismsarediscussedResultsshowthatthethree—dimensionalseparationofthewavycylindermaysup

9、presstheformationofshockwaveandimprovethestabilityofshear1ayers，leadingtoweakeningtheshockwaveinduceddragandsurfacepressurefluc七uation，aswellastheincreaseofbasepressureTherefore，thewaⅣycylindercanreducedragandsuppressthe