In this paper, the compact gas-kinetic scheme for compressible flow is extended to hybrid unstructured mesh. Based on both cell-averaged flow variables and their gradients updated from time accurate gas evolution model at cell interfaces, a compact third-order least-square-constrained reconstruction can be obtained on unstructured mesh and a multi-resolution WENO reconstruction is adopted in case of discontinuous solutions. Moreover, a compression factor for the cell-averaged gradients is proposed to take into account the possible discontinuity in flow variables at cell interface, which significantly improves the robustness of the compact scheme for high-speed flow computation on irregular mesh and preserves the accuracy. Numerical tests from incompressible to hypersonic flow are presented to demonstrate the broad applicability of the gradient-compression-based high-order compact scheme.
翻译:在本文中,压缩流的压缩气体动力学计划扩大到混合的无结构网格。根据细胞平均流变量及其从细胞界面的准确气体进化模型时更新的梯度,可以在无结构网格上获得压缩的三阶最小孔限制的重建,并在不连续的解决方案中采用多分辨率WENO重建。此外,还提出了细胞平均梯度压缩系数,以考虑到细胞界面流动变量可能不连续的情况,这大大提高了对非正常网格进行高速流算的紧凑办法的稳健性,并保持了准确性。介绍了从不压缩到超音速流的数值测试,以证明基于梯度压强波压紧凑法的广泛适用性。