Numerical simulation study on propeller slipstream effect on unmanned air vehicle with propeller engine

For the layout design of an Unmanned Air Vehicle (UAV) with propeller engine, application of three dimensional numerical simulation method on the slipstream aerodynamic effect is investigated based on Multiple Reference Frame (MRF) model. The reseach results shown that the flow field of the MRF model is consistent with true propeller flow, and MRF simulates aerodynamic interference accurately. The influence of propeller slipstream on the aerodynamic performance of an UAV at the status of taking off is most significant, becomes weaker at the status of climbing and the least at the status of cruising. The influence of propeller slipstream is enhanced with the increment of propeller thrust and keeps nearly the same if two sets of propeller who have same thrust but different blade attack angle. The pressure drag on the afterbody of the UAV fuselage increases rapidly because of the effect of propeller slipstream flow, deteriorates the aerodynamic performance of the UAV evidently.