重叠网格洞面优化技术的改进与应用

针对传统割补法在壁面狭缝处网格重叠失败的问题,提出了以单元顶点状态进行洞面优化的vertex方法及以单元大小进行洞面优化的volume方法的两种改进方法。这两种方法将传统割补法中切割和填补两步搜索方法改为一步搜索方法进行重叠网格的洞面优化。通过数值试验证明:两种洞面优化方法都能很好地解决壁面狭缝网格重叠问题,网格重叠区域流场数值传递正确,计算结果与试验值吻合,优化效率高,收敛速度快。volume优化方法与vertex优化方法相比可以减少由网格大小不对等引起的数值误差,计算结果和计算精度均优于vertex优化方法。

Improvement of Hole-surface Optimization Technique in Overset Grids and Its Application

The traditional cut-paste algorithm is usually unsuccessful in solving the assembly of an overset grid system between slit walls. In order to resolve this problem, two improved methods, the vertex method and the volume method, are presented in this article. The vertex method is based upon the grid cell vertex state and the volume method upon the grid cell size. The two methods change the two-step searching methods of cut and paste to a single step searching method to optimize the hole-surface. The results of the three example cases show that the two improved methods can solve the above problem successfully and they are able to transmit field data between the overset regions correctly. Furthermore, the computational results agree well with the experimental data, the optimization efficiency is higher and the rate of convergence is faster than the cut-paste method. The volume method, compared with the vertex method, can reduce the numerical error caused by the mismatch of grid sizes in the overset grid system, and obtain a better result and accuracy.