Transition experiments in a boundary layer with embedded streamwise vortices
Transition experiments in a boundary layer with embedded streamwise vortices
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DOI：
10.1063/1.868605
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发表时间：
1995-04
影响因子：
4.6
通讯作者：
A. Bakchinov;G. R. Grek;B. G. B. Klingmann-B.-G.-B.-Klingmann-98015600;V. Kozlov
中科院分区：
文献类型：
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作者：
A. Bakchinov;G. R. Grek;B. G. B. Klingmann-B.-G.-B.-Klingmann-98015600;V. Kozlov
The stability of a flat plate boundary layer modulated by stationary streamwise vortices was studied experimentally in the T‐324 low speed wind tunnel in Novosibirsk. Vortices were generated inside the boundary layer by means of roughness elements arranged in a regular array along the spanwise (z‐) direction. Transition is not caused directly by these structures, but by the growth of small amplitude traveling waves riding on top of the steady vortices. This situation is analogous to the transition process in Gortler and cross‐flows. The waves were found to amplify up to a stage where higher harmonics are generated, leading to turbulent breakdown and disintegration of the spanwise boundary layer structure. For strong modulations, the observed instability is quite powerful, and can be excited ‘‘naturally’’ by small uncontrollable background disturbances. Controlled oscillations were then introduced by means of a vibrating ribbon, allowing a detailed investigation of the wave characteristics. The instability...
