A novel, adaptive discontinuity fitting technique has been further developed on unstructured dynamic grids to fit both shock waves and contact discontinuities in steady flows. Moreover, in order to efficiently obtain shock-fitting solutions, two strategies, direct-fitting and indirect-fitting, have been proposed to, respectively, deal with simple and complex flows. More specifically, without first computing the flow field by a shock-capturing method, the direct-fitting strategy, mainly dealing with these discontinuities of which topologies are clearly known, can quickly obtain the solutions by initially presetting an approximate discontinuity front. By contrast, the indirect-fitting strategy, especially in coping with the complicated discontinuity structures, must utilize both shock-capturing solutions and shock detection techniques to first determine initial discontinuity locations. The two strategies have been successfully applied to a series of compressible flows, including a two-dimensional flow with type IV shock–shock interaction and a three-dimensional flow with type VI interaction. In addition, comparing the fully-fitting solution with the partially-fitting solution in the discontinuity interaction region, it is indicated that an accurate result can be acquired if all the discontinuities in the vicinity of interaction points are fully fitted. Nevertheless, the computational accuracy of expansion waves can indeed significantly affect the downstream discontinuities.

中文翻译：

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一种非结构化动态网格的自适应间断拟合技术

在非结构化动态网格上进一步开发了一种新颖的自适应不连续性拟合技术，以拟合稳定流中的冲击波和接触不连续性。此外，为了有效地获得冲击拟合解决方案，已经提出了两种策略，直接拟合和间接拟合，分别处理简单和复杂的流动。更具体地说，直接拟合策略无需先通过激波捕获方法计算流场，主要处理这些拓扑结构已知的不连续性，通过初步预设一个近似的不连续性前沿，可以快速获得解。相比之下，间接拟合策略，尤其是在应对复杂的不连续结构时，必须同时利用冲击捕获解决方案和冲击检测技术来首先确定初始不连续位置。这两种策略已成功应用于一系列可压缩流动，包括具有 IV 型激波相互作用的二维流动和具有 VI 型相互作用的三维流动。此外，将不连续性相互作用区域的完全拟合解与部分拟合解进行比较，表明如果相互作用点附近的所有不连续性都完全拟合，则可以获得准确的结果。尽管如此，膨胀波的计算精度确实会显着影响下游的不连续性。包括具有 IV 型冲击-冲击相互作用的二维流动和具有 VI 型相互作用的三维流动。此外，将不连续性相互作用区域的全拟合解与部分拟合解进行比较，表明如果相互作用点附近的所有不连续性都完全拟合，则可以获得准确的结果。尽管如此，膨胀波的计算精度确实会显着影响下游的不连续性。包括具有 IV 型冲击-冲击相互作用的二维流动和具有 VI 型相互作用的三维流动。此外，将不连续性相互作用区域的完全拟合解与部分拟合解进行比较，表明如果相互作用点附近的所有不连续性都完全拟合，则可以获得准确的结果。尽管如此，膨胀波的计算精度确实会显着影响下游的不连续性。表明如果相互作用点附近的所有不连续点都完全拟合，则可以获得准确的结果。尽管如此，膨胀波的计算精度确实会显着影响下游的不连续性。表明如果相互作用点附近的所有不连续点都完全拟合，则可以获得准确的结果。尽管如此，膨胀波的计算精度确实会显着影响下游的不连续性。