基于风洞试验的非定常气动力微分方程建模方法

Unsteady Aerodynamic Modeling Method Using Differential Equations Based on Wind Tunnel Test

为准确描述大攻角非定常运动中非定常气动力的气动特性,研究了以微分方程为基础的非定常气动建模方法。在某战斗机大振幅偏航、滚转单自由度及偏航-滚转耦合运动风洞试验的基础上,对偏航力矩、滚转力矩建立微分方程模型,分析研究不同频率、同一侧滑角情况下,气动力的迟滞时间;然后对高频运动下的气动力进行拟合,进而建立高频运动下的气动力微分方程模型。研究表明:模型可精确预测不同机动下非定常气动特性;建模方法具有较强的工程可行性。

In order to describe the unsteady aerodynamic performance in unsteady movement at high angle of attack,the unsteady aerodynamic modeling method is studied based on the differential equations.The differential equation models of yawing moment and rolling moment are built on the basis of experimental data,including the yawing,rolling and coupled yawing-rolling of flight vehicle.The hysteresis of aerodynamics is analyzed in the conditions of same sideslip angle and different frequencies,then the aerodynamic data of high frequency motion are fitted,and so the aerodynamic differential equation model of high frequency motion is set up.Results show that the model can accurately predict the flight vehicle unsteady aerodynamic characteristics under different flight conditions,and the modeling method has strong engineering feasibility.