Anisotropic Mesh Adaptation For Shock-Flame Interaction Computation

This article mainly focuses on the shock-flame interaction of the combustion in supersonic turbulent flow, utilizing the method of anisotropic mesh adaptation to test numerical calculation.However, there are a bunch of technological difficulties and challenges in the numerical simulation research of the shock-flame interaction. The first point is that the features of flow field are complex, In the flow field, there exist shock wave, flame, boundary layer, shock wave discontinuity surface and other kind of flow fields, in which the spatial distribution of physical quantities has strong anisotropy, namely directionality. Second, in the process of shock-flame interaction, there will take place the phenomenon of turbulent combustion. Turbulence has strong connection with release of heat from combustion. It also has strong diffusibility, large Reynolds number, and vortex. Third, there is non-stationarity in turbulent and shock-flame interaction process. That is to say, a large span of dimension exists in time and space, which adds difficulty and calculated amount to accurately describing the flow field information.We use numerical simulation to do research about shock-flame interaction which has above-mentioned difficulties. The article mainly resorts to the technological means and methods from the following four aspects:mesh, format, adaptation and combustion mode to build a numerical simulation tool for shock-flame interaction. The mesh adopted in the article is anisotropic mesh, of which the feature of anisotropy will solve the problems of flow field physical quantity having anisotropy. As to the format, the article adopts two-step Taylor Galerkin format, which is provided with three order accuracy in time and space, and has low dissipation. In addition, the feature of Jamesen artificial viscosity thought capture flow field shock wave is also introduced. The combustion model adopted is thickened flame model (combined with large eddy simulation) to do numerical simulation on turbulent flow combustion. The solution technique of adaptivity is applied in the article, solving the problem of the existance of non-stationarity in combustion process, increasing the accuracy and efficiency of calculation.In the view of four simulation techniques, we build a numerical simulation tool for shock-flame interaction. We use the strategy of governance, from the physical point to analyze flow field structure in shock-flame interaction. And we do numerical simulations for shock structure, flame structure, turbulent combustion, etc. Comparing the results with the experimental data or analytical solutions verifies that in the shock-flame interaction process, the adaptation can accurately describe the flow field information and feature, and realize grid resources distribution rationally with the reduction of computing scale.