关键词: 气动力降阶模型, 大攻角气动力, 刚弹耦合动力学模型, 飞行动力学仿真, 阵风响应

Abstract: For low-speed aircraft, gust is more likely to lead to the generation of nonlinear aerodynamic force and nonlinear aeroelastic response, consequently causing flight safety problems. To study these nonlinear problems, the classical panel method cannot meet the accuracy requirements, and the Computational Fluid Dynamics (CFD)/Computational Structure Dynamics (CSD) full order coupling analysis is inefficient. Therefore, it is necessary to establish a flight dynamics analysis model with high precision and high efficiency to satisfy the engineering requirements. A nonlinear aerodynamic Reduced-Order Model (ROM) is proposed in this paper to predict the nonlinear aerodynamic force of low-speed aircraft under high amplitude gusts. Taking a flying wing aircraft model in a wind tunnel test as an example, we obtain the aerodynamic data of the model with the CFD method. A linear aerodynamic ROM and a nonlinear aerodynamic correction ROM of the flying wing aircraft model are established by the Autoregressive Moving Average (ARMA) method and Radial Basis Function (RBF) neural network method, respectively. An elastic aircraft simulation model is then established and the response of the model under gusts is simulated and analyzed by combining the rigid-elastic coupling flight dynamics equation and the aerodynamic ROM. Comparison of the simulation results with the wind tunnel test results and the CFD/CSD calculation results shows that the performance of the elastic aircraft simulation model based on nonlinear aerodynamic ROM is better than that of the model based on linear aerodynamic ROM in aerodynamic prediction, stability analysis and gust response analysis, and that the analysis results are in good agreement with the test results and CFD/CSD analysis results. The time cost of the proposed simulation model based on ROM is much lower than that of the CFD/CSD analysis method under the same working conditions, indicating the applicability of the proposed model to the engineering practice.

Key words: aerodynamic reduced-order model, aerodynamic force with high angle of attack, rigid-elastic coupling dynamic model, flight dynamics simulation, gust response