Wind Tunnel Test Results and Performance Prediction for a Ducted Fan with Collective and Cyclic Pitch Actuation for VTOL with Efficient Cruise

摘要

This paper describes wind tunnel tests of a new ducted fan, designed for efficient cruise. The fan uses simple helicopter blades. Force and moment data are presented for the isolated duct, and for the ducted fan in hover, with and without crosswinds, and in near axial-flow conditions. Figure of merit and thrust and power coefficients are presented for the no-crosswind case, with three different duct lips. The duct's internal diameter is 600 mm. The duct has circumferentially varying airfoil sections, and is designed for high lift in axial flow. Ring wing maximum test Reynolds number is 250,000, and ducted fan maximum test Reynolds number is 209,000. The duct's fan blades have variable cyclic and collective pitch. Hover collective settings from 0° to 25° , and helicopter-type cyclic pitch settings from 0° to 7.5° were tested.