风力机翼型气动计算的降阶模型研究

Reduced Order Models for the Aerodynamic Calculation of the Wind Turbine Airfoil

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。

POD-based reduced-order model is applied to the aerodynamic simulation of the wind turbine airfoils. CFD method is used to get a series of snapshots; With the POD methods （proper orthogonal decomposition） to fluid field can be expressed as get a few basis of the flow modes. a linear combination of the modes; For the specific fluid problem, any With Galerkin projection onto the POD basis, the N-S equations can be changed into a set of ordinary differential equations with only a few DOFs as many as 10 modes, reducing the computation time. Two-dimensional flow around an airfoil of the steady and unsteady problems are analyzed, the results show that the reduced order models can simulate the flow characteristics well, compared with the direct CFD simulation accuracy equivalently, but improve the computational efficiency greatly.