低Re数領域でのNACA0012翼まわりの流れ場: 第2報 境界層の特性

Abstract

Measurements of flow field over a NACA0012 airfoil were performed with hot-wire anemometer at three cases of Reynolds number of 10,000, 30,000 and 50,000. We focus our attention on characteristics of both laminar separation region and separation bubble on the airfoil in order to find the characteristics of the flow field responsible for peculiar aerodynamic nature of the airfoil in low Reynolds number regions. This paper deals with separation and reattachment of the boundary layer on the airfoil to make certain the conclusions of our previous papers. By results of velocity distributions, laminar separation region is confirmed in low angle of attack regions, separation bubble is also confirmed on the airfoil as increasing of angle of attack. Shape factor of H and second shape factor of K are calculated by boundary layer profiles and are applied criterions of boundary layer separation, separation and reattachment points can be estimated on the airfoil. We find overviews of flow field phenomena involving a separation bubble in low Reynolds number regions.