Key Factors in Determining the Magnitude of Vorticity in Turbulent Plane Wakes

We examine the effects of local turbulence Reynolds number R(lambda) and inflow conditions on the magnitude of vorticity in plane turbulent wakes. Measurements of the spanwise component (omega(3)) of the fluctuating vorticity vector omega = omega(1)i + omega(2)j + omega(3)k (here the subscripts 1, 2 and 3 denote the streamwise, lateral and spanwise directions, respectively) are made in turbulent wakes of a screen and a circular cylinder. Lateral distributions of omega(3)* (normalized) in general depend on both R(lambda) and inflow conditions. In the developing region, as the downstream distance x(1) increases, omega(3)* increases significantly in the screen wake but decreases slightly in the cylinder wake. Far downstream in the self-preserving region, omega(3)* increases linearly with R(lambda) while it no longer varies with x(1) and depends weakly on the influence of inflow conditions. Our analysis suggests that these findings from the measurement of omega(3)* should apply for the magnitude of omega.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000274360800042&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, MultidisciplinarySCI(E)中国科技核心期刊(ISTIC)0ARTICLE2null2