The Clean Sky ‘Card’ Project: Wind Tunnel Measurements of a Model Helicopter Rotor and Fuselage Drag

Results of a wind tunnel test campaign to assess technologies for improvement of helicopter fuselage and rotor system drag are described in this paper. The work done was part of the EU funded Clean Sky CARD project (Contribution to Analysis of Rotor-hub Drag reduction). Wind tunnel tests of an accurate 1/4 scale, Airbus Helicopters H155 were performed in a variety of advance ratios, pitch angles and side-slip angles to simulate cruise and approach conditions. 1/3rd of the rotor diameter was represented in the model, and the rotor was otherwise rigid and un-actuated (fixed blade pitch around the azimuth). Rotor system forces and moments were measured independently of the fuselage forces and moments, thus allowing the various contributions to the total drag to be evaluated. The paper describes elements of the model design and data analysis for drag and power evaluation, and presents sample results.