摘要
Theturbulencestructuresnearashearedair-waterinterfacewereexperimentallyinvestigatedwiththehydrogenbubblevisualizationtechnique.Sur-faceshearwasimposedbyanairflowoverthewaterflowwhichwaskeptfreefromsurfacewaves.Resultsshowthatthewindshearhasthemaininfluenceoncoher-entstructuresunderair-waterinterfaces.Low-andhigh-speedstreaksformintheregionclosetotheinterfaceasaresultoftheimposedshearstress.Whenacertainairflowvelocityisreached,'turbulentspots'appearrandomlyatlow-speedstreakswithsomecharacteristicsofhairpinvortices.Atevenhighershearrates,theflowneartheinterfaceisdominatedprimarilybyintermittentburstingevents.Thecoher-entstructuresobservednearshearedair-waterinterfacesshowqualitativesimilaritieswiththoseoccurringinnear-wallturbulence.However,afewdistinctivephenomenawerealsoobserved,includingthefluctuatingthicknessoftheinstantaneousboundarylayerandverticalvorticesinburstingprocesses,whichappeartobeassociatedwiththecharacteristicsofair-waterinterfaces.
出版日期
1999年04月14日(中国期刊网平台首次上网日期,不代表论文的发表时间)