一种适于多级粘性计算的三维网格生成方法

Generation of three dimensional grid for viscous multistage numerical simulation

给出了一种适于多级叶片机粘性计算的三维网格生成方法．通过对Ｎ．Ｓ方程求解对网格特殊性要求的分析，给出了几种形式的网格在多级计算中的优缺点，发展了一种代数法与微分方程求解相结合的网格生成技术．采用本方法生成的网格在壁面附近具有Ｏ 型网格的特点，而网格的拓扑结构确是Ｈ 型的，因此该种网格不但可以方便地在级间施以加密技术，以对该区域流场进行精细描述，而且该方法可以保证网格在壁面的正交性，以及网格在近壁区域的任意划分，保证了边界条件在壁面得以准确而简单地实施，减少了壁面附近由于网格畸变所带来的数值扩散效应．同时将求解网格的Ｐｏｓｓｉｏｎ 方程的简化为方程，避免了由于源项控制不当而造成网格质量降低的问题．

This paper proposed a method of generating three dimensional grid for viscous multistage numerical simula tion. The advantage and shortcoming of three kinds of grid topology for multistage viscous calculation were discussed, and developeda partial difference equation grid generation method which combined an algebraic treatment in the zone near wall. The grid generated by this method is characterized by possessing the feature of O type grid in the zone near wall and H grid topology. These characters make it convenient to adapt grid on the interface between rotor and stator, so the flow field structure can be described in details. This method make it easy to distribute grid nodes in the zone near wall and also guarantees the grid orthogonal in this zone. Possion equation was also simplified into Laplace equation, that could avoid the decrease of grid quality caused by bad control of source term of Possion equation.