RESUMO

The influence of unequal strength opposing shear layers on the vortex formation process and coherent wake structure in the near-wake region of a triangular cylinder is experimentally investigated. Phase-averaged Laser Doppler Velocimetry measurements were made in the wake of a triangular cross-section cylinder for a Reynolds number of 22 500. The relative intensity of the shear layers was adjusted through the angle of incidence, α. The influence α on the flow characteristics, specifically the shedding frequency and surface pressure distribution, was also studied. It is shown that even a mild difference in the strength of the shear layers can significantly modify the structure of the wake and shed vortices.