はく離・再付着流れに対する主流乱れの影響 : はく離角度が変化する場合

抄録

Effects of free-stream turbulence on a series of two-dimensional separated-reattaching flows ( separation bubbles ) were investigated experimentally in a low speed wind tunnel. Models tested were two-dimensional triangular cylinders with a tail plate. Some important properties of the separation bubbles were measured with a split-sensor driven by constant-temperature hot-wire anemometers. The effect of the turbulence on the reattachment length was found to be not uniform with respect to the separation angle. Large-scale vortices were formed by coalescence in the reattaching zone of the shear layer and were shed downstream with a non-dimensional frequency 0.65U_o/x_R, which was the same for all combinations of the separation angle and the free-stream turbulence employed in this study. Geometry of the separated shear layer suggested that the large-scale vortices in the reattaching zone became flatter as x_R increased.