LOW SPEED EXPERIMENTAL INVESTIGATION AND FLOW VISUALIZATION OF AIRFOIL TRAILING-EDGE DEVICES

摘要

This paper presented the flow visualization experiment results of the airfoil of the transport in the water tunnel of China Aerodynamics Research and Development Center (CARDC), the existence of the trailing-edge devices affected the flow field around the upper and lower surfaces, especially on the lower surface, the trailing vortex layer had been reformed, and the separate flow on the upper surface had been controlled. To explain the phenomena, the pressure measure experiment in the NF-3 wind tunnel of North-West Polytechnic University of China (NWPU), and the force measure experiment in the 2D wind tunnel of CARDC were carried out. The result showed that the pressure distribution on the upper surface was changed with the height of Gurney and serrated flap, and the pressure value on the lower surface was increased by the increased height of the trailing-edge devices. It was demonstrated that, with the serrated flap which height was 4% of the airfoil local chord length or the Gurney flap which height was 2% of the airfoil local chord length, the effect of the trailing-edge device on the airfoil aerodynamic character was optimum, with the increased airfoil's lift-drag ratio range from 141% to 8.7%.