A.V.Voskoboinick, V.A.Voskoboinick, S.A.Isaev, V.L.Zhdanov, N.V.Kornev, I.Turnow Vortex flow bifurcation inside the spherical dimple in a narrow channel |
Applied hydromechanics, Vol. 13 (85) ¹ 4, (2011) |
| ENGThe numerical and physical simulation results of the vortex flow structure which is formed inside a deep spherical dimple in a narrow hydrodynamic channel are presented. The results of flow calculations by the methods of URANS, LES and POD analyze are shown. The visual features of vortex flow are demonstrated and the regimes at which symmetric and asymmetric large-scale vortices are generated inside a spherical dimple are indicated. The research results of the wall-pressure fluctuation field inside the dimple, measured miniature piezoceramic and piezoresistive sensors, are presented, and it is found out the antiphased vibrations of the pressure field in the places of forming and break up of the vortex systems outside from the dimple. A structure, location and scales of the vortex systems inside the dimple for the laminar and turbulent regimes of flow are resulted. It is set, both in numeral researches and experimentally, that at the turbulent flow around of deep spherical dimple asymmetric inclined vortices are formed in it, which quasiperiodic are switched from one part of the dimple in other. Break up angle of the asymmetric large-scale vortices outside from the dimple is increased with growth of Reynolds number and makes ±45° for Red=40000 and ±60° for Red=60000. |
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KEY WORDS: vortex flow, numerical simulation, spherical dimple, large-scale vortices |
| TEXT LANGUAGE: Russian |