Performance improvements of helicopter basic fuselage model by passive vortex generators

Abstract

Wind-tunnel tests of a heavy-class helicopter model were carried out to evaluate the effectiveness of a passive flow control system in alleviating fuselage parasite drag. An array of counter-rotating vortex generators was installed to reduce/remove the flow separation occurring on the rear-loading ramp responsible for the high-pressure drag. Novel technical solutions for the VGs’ design and location were selected compared to the previous work. A geometrically scaled 1:7 basic fuselage of a heavy-class helicopter was investigated with and without a passive flow control system using various measurement techniques. In particular, pressure measurements and stereo particle image velocimetry surveys were performed to obtain physical insights into load measurements. This paper reports promising results from wind-tunnel experiments, including the observation of significant drag reduction for a wide range of fuselage angles of attack and side slip angles without a negative impact on other aerodynamic characteristics.