Aerodynamic installation effects of lateral rotors on a novel compound helicopter configuration
Tom Stokkermans (TU Delft - Flight Performance and Propulsion)
Bambang Soemarwoto (Royal Netherlands Aerospace Centre NLR)
M Voskuij (TU Delft - Flight Performance and Propulsion)
Raphaël Fukari (Airbus Helicopters)
L. L.M. Veldhuis (TU Delft - Flight Performance and Propulsion)
Paul Eglin (Airbus Helicopters)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Installation effects of the lateral rotors for a compound helicopter were investigated by means of unsteady CFD simulations. The helicopter featured a box-wing design for additional lift in cruise and wingtip-mounted lateral rotors in pusher configuration for additional thrust in cruise and counter-torque in hover. It was found that propeller performance installation effects for a compound helicopter are highly beneficial in cruise, while some penalties exist in extreme and specific cases in hover and autorotation. In cruise the main interaction was between the wing and lateral rotors, resulting in a propulsive efficiency increase up to 10.6% due to wingtip vortex energy recovery. In hover the main rotor slipstream resulted in a near perpendicular inflow to the lateral rotors, with a disturbance from the wings due to the deflection of the main rotor slipstream. For higher than nominal lateral rotor thrust settings, this resulted in a performance penalty. In autorotation a small power installation penalty was present due to inflow disturbances.