Unsteady Aerodynamic Identification Based On High-order Volterra Kernel

The aeroelastic problem is prominent when the aircraft is flying at transonic speed.The traditional potential flow equations obtained by simplifying the N-S equation based on linear assumptions have significant deviations in transonic aeroelastic analysis.The CFD method can solve the unsteady aerodynamic of each time step with high precision.Since the 21 st century,some scholars have proposed the concept of unsteady aerodynamic reduction model based on CFD method.The so-called unsteady aerodynamic reduction model is to provide quantitative and accurate description of the mathematical model of CFD numerical simulation for the unsteady flow field at a much lower computational cost than the original.This dissertation is based on the research of unsteady aerodynamic reduction model based on CFD method.The transonic unsteady aerodynamic reduction model is established by using the third-order Volterra series represented by piecewise quadratic multi-wavelet.Prediction of transonic unsteady aerodynamic forces.The work of this paper is mainly as follows:(1)Based on the CFD method,the transonic constant aerodynamic calculation of the binary wing segment and the unsteady aerodynamics of the pitch oscillation are numerically simulated,and compared with the experimental data.(2)Construct a third-order kernel function expressed in piecewise quadratic multiwavelets,and a thirdorder Volterra series of the system.(3)The multi-dimensional swept frequency input signal is designed,and the unsteady aerodynamic output data is obtained by CFD calculation.The unsteady aerodynamic reduction model of the single-input/single-output system expressed by the third-order Volterra series and the first-order Volterra series are expressed.Input/multiple output unsteady aerodynamic reduction model.(4)The unsteady aerodynamic reduction model of a single-input/single-output system represented by a third-order Volterra series predicts the unsteady aerodynamic forces of the binary wing segments doing pitching motion in the transonic region.