非结构网格划分的喷管流场计算中单调性约束条件的研究

提出了一种限制网格单元内梯度值大小的单调性约束条件 ,以减少间断附近数值解的振荡。这一约束条件在算法上具有易于实现的优点 ,因此能够很方便地用于非结构网格划分的流场计算中。文中给出了二阶Godunov格式使用这一约束条件之后 ,求解喷管流场得到的数值计算结果 ,可以看出 ,数值解较好地反映了激波的有关特征

A Monotonicity Limiter Algorithm on Unstructured Grids for Computation of Nozzle Fields

A new monotonicity limiter algorithm is presented,particularly suited for unstructured grid applications,so as to constrain the interpolated values on either side of the interface by imposing a monotonicity coefficient on the gradient of each cell.The coefficient depends not only on the local gradient value but also on the gradient values of the surrounding cells,so that the solutions obtained be devoid of the oscillation.Numerical computations of the nozzle flows have been carried out.The results show that in conjuction with the limiter,the second order Godunov scheme produces good resolution of shock.