三次元境界層剥離の可視化と熱線計測

抄録

The flow in the cross-flow separation of an axisymmetric paraboloid at 30, 40 and 50 deg angle of attack has been investigated experimentally by smoke visualization technique and hot wire anemometer. Reynolds numbers are 9.0×10³ and 1.8×10⁴ referred to the base diameter. Laser light sheet method is used in studying the structure of the vortices in cross-sectional flow. The development of streamwise vortices in each section of the body is visualized. X-type probe was used to measure three dimensional velocity fields over the axisymmetric paraboloid. Velocity fluctuations at sampling time of 4 kHz have been also evaluated. The extent of longitudinal vortices, such as main, primary-and secondary vortices, and the change of r.m.s. value in various cross-sections are presented. The variation of vortex patterns is shown for each cross-section, angle of attack and Reynolds numbers. It has been confirmed that each streamwise vortex is related to the velocity fluctuations.