Aerodynamic analysis of helicopter side intake variants by full scale wind tunnel measurements

Abstract

The work presented in this paper aims at the aerodynamic optimization of engine side air intakes of a lightweight helicopter. For this purpose wind tunnel (W/T) tests are conducted on a novel full scale model of a helicopter fuselage section at the Institute of Aerodynamics and Fluid Mechanics of the Technische Universität München (TUM-AER). The new wind tunnel model includes a duct system, venturi meter and a radial fan to provide engine mass flow rates corresponding to realistic helicopter operation conditions. With 5-hole pressure probes significant trends on the total pressure drop and distortion coefficients are found at the Aerodynamic Interface Plane (AIP) for three different air intakes tested in hover and forward flight conditions. Further investigations are conducted concerning local surface pressure distributions.