飞行器快速俯仰产生大迎角非定常气动力数学模型研究

On an Unsteady Aerodynamics Model for Pitching-Oscillating Body at High Angle of Attack

在 Goman提出的状态空间模型的基础上 ,开展了有关建立大迎角非定常气动力数学模型问题的研究。针对以往在运用状态空间模型建立大迎角非定常气动力数学模型中存在的问题 ,通过分析状态方程中非定常影响参数与减缩频率 (或无量纲俯仰角速率 )的关系 ,建立了改进数学模型的基本思路。同时运用插值方法给出了二者之间的关系 ,并将此结果引入到状态方程中。经过辨识验算后表明 ,改进后的模型不仅改善了该模型对气动力的预测准确度 ,同时也提高了描述大迎角非定常气动力的能力。

An improved state space representation for the unsteady aerodynamics with large angle of attack was presented. The first order differential equation proposed by Goman. was used to model the dynamics of flow separation and vortex burst, but unsteady effect of the rate of dynamic motion of the airframes was considered. The aerodynamic coefficients can express as an algebraic series in terms of input variables. Based on wind tunnel test data, the unknown parameters in the model can be identified by minimum mean square method and maximum likelihood method. Three examples of the unsteady aerodynamic model with large angle of attack were analyzed. It is shown that the performance of the present model is much better than one of Goman's original model.