Comparative Study of Aerodynamic and Aeroacoustic Behavior of Flat Plate Airfoils With Different Trailing Edge Geometry

Abstract

The present study compares the aerodynamic and aeroacoustic behavior of the flow past two flat plate airfoils; viz. blunted trailing edge and sharp trailing edge, having a fixed aspect ratio of 1.867. The study is performed experimentally showing variance in lift and drag at two different velocity of 20m/s and 30m/s and at different angles of attack, viz. 5°, 12°, 20°, 25°, 30°. All the models are prepared by mild steel and the studies are conducted using 300×300×1000 mm subsonic wind tunnel. Results show that the drag coefficient in sharp trailing edge reduces significantly by a maximum amount of 22%. The lift coefficient, however, does not change significantly. Uncertainty analysis performed shows that maximum percentage of uncertainty in each case is less than 5%. Aero acoustic measurement of the noise radiated by the trailing edge of the two flat plates is performed in a reflecting environment at a velocity of 20m/s and at two different angles of attack of 10° and 15° with ¼’’ inch far field microphone mounted near the trailing edge of the airfoil in the test section. The spectra obtained indicate that the noise from the sharp trailing edge is consistently lower than the blunt trailing edge. Thus, this paper adequately demonstrates the role of trailing edge in modifying the aerodynamic as well as aero acoustic characteristic.