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将基于POD的降阶模型应用于风力机翼型的气动研究。首先应用CFD数值模拟得到一系列快照结果;应用基于本征正交分解(POD)的方法得到流场的一组基模态,认为对于所研究的问题,任一流场可以由这些基模态通过线性表达得到;对控制方程进行Galerkin投影,得到降阶模型,将离散求解N-S方程的问题转化为一组只有十几个自由度的常微分方程,从而减少计算时间,提高计算效率。并对二维翼型的绕流的定常和非定常问题进行了分析,计算结果表明,降阶模型可以较好地捕捉流动的特征,与直接CFD模拟相比计算精度相当,但大幅有效地提高了计算效率。
The POD-based reduced-order model is applied to the aerodynamic research of wind turbine airfoils. Firstly, a series of snapshots are obtained by numerical simulation of CFD. A set of fundamental modes of flow field are obtained by using the method of eigen-orthogonal decomposition (POD). It is considered that any flow field can be represented by these fundamental modes Which is obtained by linear expression. The control equation is galerkin projection, and the reduced order model is obtained. The problem of solving the NS equation discretely is transformed into a set of ordinary differential equations with only a dozen degrees of freedom, so as to reduce the calculation time and improve the computational efficiency. The steady-state and unsteady flow around a two-dimensional airfoil are analyzed. The calculated results show that the reduced-order model can capture the characteristics of the flow better than the direct CFD simulation. However, the computational accuracy is improved substantially and effectively The calculation of efficiency.