基于变形网格技术的翼型结冰数值模拟研究

Exploring Numerical Simulation of Icing Flow-Field of Airfoil Based on Grid Deformation Technique

翼型结冰的过程实质上是其外形随时间改变的过程。对于结冰的数值模拟,计算网格必须随着翼型外形的改变而相应的变化。文章利用非定常N-S方程模拟翼型结冰增长的过程,使用基于无限插值法(TFI)的变形网格技术生成非定常计算的网格。变形网格技术是在初始网格的基础上将物面的变化通过插值均匀分布到场内网格点,该方法能够最大限度地保留初始网格特征,而且生成过程与初始网格不相关。非定常计算利用上一次结冰的流场为初值,而不用从初场重新开始,而且变形网格技术生成网格也远远比求解椭圆型方程快,总的计算时间大幅减少。为了验证方法的有效性,文章对NACA0012进行了结冰数值模拟,计算结果与参考文献的实验和计算结果吻合。

The ice accretion process is essentially one in which the airfoil shape deforms as a function of time. For an ice accretion prediction, the iced airfoil shape and the grid need to change in response to the deforming airfoil. This paper attempts to use the unsteady N-S code to simulate the icing flow-field. The grid for unsteady calculation is mainly based on a transfinite interpolation （TFI） algorithm, which can be seen as an interpolation method. The grid generated by grid deformation technique keeps the characteristics of the initial grid and is independent of the initial grid generation. The grid deformation technique costs less time than the elliptic grid generation method. In order to verify the efficiency of the present method, the ice accretions on NACA 0012 airfoil are numerically simulated. The numerical results are given in Fig. 4 （comparing our results with the experimental results and calculated ones given in Refs. 6 and 7 respectively by G.E. Addy and G. Fortin et al） and in Figs. 5 through 8. Our results in Fig. 4 are respectively in good agreement with those given in Ref. 6 and in fairly good agreement with those given in Ref. 7.