翼型上のShort Bubble内部に生ずる低周波数速度変動に関する実験的研究

抄録

Experimental Studies have been conducted to investigate velocity disturbances observed inside the short bubble formed on NACA0012 airfoil. Measurements were done at the angle of attack 10^° and at the Reynolds number of 1.3×10⁵ based on the chord length. In the transition area in the short bubble, a dominant low frequency velocity fluctuation was observed. This frequency is much lower than that reported in the previous short bubble measurements. The phase averaging technique has been applied to analyze this low frequency velocity fluctuation. It is shown that the direction and the amount of the flow velocity vector inside the separated layer just after the separation point changes periodically. The frequency of these behaviors agrees with the observed low frequency velocity fluctuation.