Heavy Class Helicopter Fuselage Model Performance Improvement using Vortex Generators

Wind-tunnel tests of a heavy-class helicopter model were carried out to evaluate the effectiveness of passive flow control system in alleviating the fuselage parasite drag. An array of counter rotating vortex generators was selected to reduce/remove the flow separation occurring on the rear loading ramp responsible of the high pressure drag. Different technical solution for the VGs design and location were selected with respect to previous work. The basic fuselage geometrically scaled 1:7 of a heavy class helicopter was investigated with and without passive flow control system. The comprehensive experimental campaign involved the use of different measurement techniques. Indeed, pressure measurements and stereo particle image velocimetry surveys were performed to gain a physical insight about the results of load measurements. This paper addresses the promising results obtained during the wind-tunnel campaign, since significant drag reduction was achieved for a wide range of fuselage angles of attack and side slip angles without the detriment of the other aerodynamic characteristics.