Uncertainty Quantification Analysis with Arbitrary Polynomial Chaos Method: Application in Slipstream Effect of Propeller Aircraft

The slipstream effect of propeller aircraft has a major impact on aircraft aerodynamic characteristics. Predicting the interaction of propeller slipstream on flow field over a complete aircraft has been an important topic in the field of fluid mechanics. In the flight test, we found that parameters in the flight data of propeller aircraft exhibit significant stochastic characteristics, and the mechanism of the influence of these stochastic parameters on aerodynamic characteristics of propeller aircraft needs to be further studied. Therefore, we combine arbitrary Polynomial Chaos method with Computational Fluid Dynamics (CFD) according to the characteristics of stochastic parameter distribution, propose an uncertainty CFD analysis method, and apply it to the aerodynamic uncertainty analysis of propeller aircraft. Results show that the standard deviation (Std) of the pressure coefficient Cp on the wing surface will form an extreme region at windward side and separation position, respectively, which will gradually decrease with the flow direction. Furthermore, the slipstream will reduce the local Std on wing surface, and the downwash caused by slipstream will change the Std distribution on the leading edge of the horizontal tail.