Numerical Analysis of the Interference Effect of Propeller Slipstream on Aircraft Flowfield

Abstract

The panel method was used for the numerical calculations in this study. The propeller vortex system rotating with its blades, and the steady horseshoe vortex system distributed on the aircraft surface were used as the mathematical model. Neumann boundary conditions were satisŽ ed at the panel control points of the blade and the aircraft panel to achieve coupling of propeller slipstream with the whole  owŽ eld of the aircraft. At each corresponding azimuth angle of the propeller, pressure coefŽ cients and induced velocities by the two vortex systems at the panel control points were calculated; from this, the average aerodynamic characteristics of the aircraft in one revolution period were obtained. The contraction effect of the three-dimensional propeller slipstream and its in uence on the  owŽ eld were considered in the computation. Results of numerical examples showed that the slipstream had a signiŽ cant effect on aircraft lift characteristics such as  ap de ecting, resulting in relatively large changes of the aircraft moment performance. Numerical results were in good agreement with the experimental data. The method presented here is suitable for both singleand multiple-propeller aircraft.