一様せん断流中にある球からの渦放出 : 中間レイノルズ数領域

概要

論文の詳細を見る
The vortex shedding frequency and the wake structure of a sphere in a uniform shear flow were experimentally investigated. The Reynolds number Re, which was defined in terms of the sphere diameter and approaching velocity at its centre, ranged from 200 to 3000. The shear parameter, which was the transverse velocity gradient of the shear flow nondimensionalized by the above two quantities, was varied from 0 to 0. 25. The critical Reynolds number beyond which vortex shedding from the sphere occurred was found to be lower than that for a uniform flow and decreased approximately linearly with increasing the shear parameter. Also, the Strouhal number St of the loop-shaped vortex which was discharged from the high-velocity side became larger than that for the uniform flow and increased as the shear parameter increased. Moreover. the formation and structure of the sphere wakes corresponding to each range of Reynolds number, which was classified into three regions, were examined on the basis of successive photographic evidence. It was found that the wake configuration did not differ substantially from that for a uniform flow.
一般社団法人日本機械学会の論文
1993-06-25