薄い境界層中に設置された物体背後の渦構造

抄録

Effect of apex angle 2α has been investigated on the behavior of the arch vortex generated from a circular cone placed in a thin laminar boundary layer. The apex angle of circular cone is in the range of 15°<2α<90°and the height H is 50mm. Then, the Reynolds number based on the height of the circular cone is 1000 and the relative boundary layer height δ/H is 0.42. The flow fields were visualized using the PIV (Particle Imaging Velocimetry). Conventional time averaged and phase averaged vector fields were obtained behind the cone. Some quantitative properties such as maximum vorticity, frequency and radius of the unsteady vortex were defined and discussed on dependence of the vortex structure on the apex angle.