On the flow instabilities in the end-wall region of a surface mounted obstacle

Visualization of flow in the around a surface mounted obstacle revealed that the pressure gradients imposed on the boundary layer amplified the formation of turbulent spots in the end-wall region. It was observed that the juncture vortices exhibited Λ waveform instability even during the stretching phase that was followed by a rapid amplification and formation of a turbulent spot. The turbulent spot spread laterally as it convected past the attachment and corner region of the end-wall flow. At the Reynolds number used in this investigation the instabilities were always initiated in the region where the primary singular point is located.