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基于线性卷积和修正因子,发展了一种多参数空间的非线性、非定常气动力降阶模型(ROM),从而高效地获得准确的非定常气动力。首先,基于阶跃响应的卷积构建线性降阶模型;然后应用拉丁超立方抽样得到参数空间内的抽样点,分别计算各抽样点处的修正因子;利用Kriging插值得到整个参数空间内的修正因子,从而得到参数空间内的修正降阶模型。以Isogai机翼为研究对象,考虑马赫数、俯仰振幅、沉浮振幅和减缩频率的变化对降阶模型精度的影响;最后将模型降阶与模型结构方程耦合,进行气动弹性分析并预测颤振边界,由此论证了该降阶模型的有效性。
Based on the linear convolution and the correction factor, a non-linear and unsteady aerodynamic order reduction model (ROM) for multi-parameter space is developed to obtain accurate unsteady aerodynamics efficiently. Firstly, a linear reduction model was constructed based on the convolution of the step response. Then, the sampling points in the parametric space were obtained by using the Latin hypercube sampling, and the correction factors at each sampling point were calculated respectively. The correction factors in the entire parameter space were obtained by Kriging interpolation , So as to get a modified reduced order model in parameter space. Taking Isogai airfoil as the research object, the influence of Mach number, pitching amplitude, up-and-down amplitude and reduction frequency on the accuracy of the reduced order model is considered. Finally, the model reduction is coupled with the model structural equation to conduct the aeroelastic analysis and predict the flutter boundary , Thus demonstrates the effectiveness of the reduced order model.