非定常気流中の Bluff Body の変動圧力特性と動的応答特性について

Abstract

The effects of pulsating flow on the flow-separation characteristics around rectangular cyl-inders were investigated both in a wind tunnel and in a water tunnel.The fluid-mechanical effects caused by pulsating flow were classified into three differenttypes concerning the enhancement-properties of shear layer instability. The first is "com-pletely separation flow type" for rather bluff bodies, the second is "unsteady separation or re-attachment flow type" for comparatively bluff bodies, and the third is "steady reattachmentflow type" for rather slender bodies. Furthermore, some fundamental considerations on theeffect of pulsating flow to aerodynamic phenomena, such as vortex-induced oscillation, gallop-ing and torsional flutter, were also briefly shown.