凹曲面に沿う縦渦崩壊の構造 (続報)

馬蹄形渦と変動流との関連について

抄録

This is a continuation of the study of boundary layer transition along a concave wall with 1m radius of curvature. The flow pattern was visualized by smoke-wire technique, and the pattern was compared with the velocity distribution, the turbulence intensity and the frequency spectrum. It is noticeable that the horseshoe-type vortices grow by entrainment of the main airflow. Further down-stream as the vortices merge with each other, they break down in the outer layer, while fluctuating flows with high turbulence intensity are produced in the high velocity gradient regions below. According to the spectrum distribution, the fluctuating flows are generated by the behaviour of the vortices, and the turbulence intensity of the flows is remarkably amplified in the inner layer.