A Real Ghost Fluid Method for the Simulation of Multimedium Compressible Flow
A Real Ghost Fluid Method for the Simulation of Multimedium Compressible Flow
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DOI：
10.1137/030601363
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
C. Wang;T. Liu;B. Khoo
中科院分区：
文献类型：
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作者：
C. Wang;T. Liu;B. Khoo
在以往的虚拟流体方法（GFM）中，重点是虚拟流体状态的定义，而真实的流体侧的压力和速度被认为是理所当然的，除了对界面附近的真实的流体节点处的密度进行校正以克服与过热相关的可能问题。人们已经发现，这样的GFM遇到了许多困难时，适用于冲击阻抗匹配（类）的问题，由于无法准确地施加界面条件。通过使用Riemann问题求解器预测紧挨着界面的真实的流体节点和虚拟流体节点的流动状态，可以施加更精确的界面边界条件，并且在很大程度上减轻了所述困难。这导致在这项工作中提出的真正的GFM的发展。一个简单而有效的扩展本方法的多维也被引入。为了克服由于大的流速梯度导致的水平集轮廓严重聚束的问题，在水平集函数的计算中构造了扩展（人工）速度场。本方法适用于各种一维和二维问题，涉及强激波界面相互作用和复杂的流动物理。
In the previous ghost fluid methods (GFMs) developed, the focus is on the definition of ghost fluid states while the pressure and velocity in the real fluid sides are taken for granted, except for the correction made to the density at the real fluid nodes next to the interface to overcome the possible problems related to overheating. It has been found that such GFMs encounter many difficulties when applied to shock impedance matching (-like) problems due to the inability of accurately imposing interfacial conditions. By predicting the flow states for the real fluid nodes just next to the interface and the ghost fluid nodes using the Riemann problem solver, a more accurate interface boundary condition can be imposed and the said difficulties are mitigated to a large extent. This leads to the development of a proposed real-GFM in this work. A simple yet efficient extension of the present method to multidimensions is also introduced. In order to overcome issues associated with the severe bunching of level set contours due to the large flow velocity gradient, an extension (artificial) velocity field is constructed in the computation of the level set function. The present method is applied to various one- and two-dimensional problems involving strong shock-interface interaction and complex flow physics.