Helicopter fuselage model drag reduction by active flow control systems

Abstract

A comprehensive experimental investigation of helicopter blunt fuselage drag reduction using active flow control (AFC) is being carried out within the European CleanSky program. The objective is to demonstrate the capability of several active technologies to decrease fuselage drag by alleviating the flow separation occurring in the backdoor area of some helicopters. The work is performed on a simplified blunt fuselage at model-scale. Two different flow control actuators are considered for evaluation: steady blowing and unsteady blowing (or pulsed jets). Laboratory tests of each individual actuator are first performed to assess their performance and properties. The fuselage model is then equipped with these actuators distributed along the loading ramp edges. This paper addresses the promising results obtained during the wind-tunnel campaign, since significant drag reductions are achieved for a wide range of fuselage angles of attack without detriment of the other aerodynamic characteristics.