Approximate Riemann solver for compressible liquid vapor flow with phase transition and surface tension
Approximate Riemann solver for compressible liquid vapor flow with phase transition and surface tension
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DOI：
10.1016/j.compfluid.2017.03.026
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发表时间：
2017-03
影响因子：
2.8
通讯作者：
S. Fechter;C. Munz;C. Rohde;C. Zeiler
中科院分区：
文献类型：
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作者：
S. Fechter;C. Munz;C. Rohde;C. Zeiler
由于需要对界面进行跟踪，所以可压缩液-汽流的尖锐界面分辨率是很麻烦的。全局动力学受局部界面现象的支配，如表面张力效应以及跨界面的质量和能量传递。这些影响施加了微妙的跳跃条件，这些条件必须在界面上本地解决。两相黎曼问题的精确解是通过一个复杂而耗时的迭代过程来实现的。此外，在整个算法中没有使用黎曼模式的大部分详细知识，因此开发一个更简单的近似黎曼求解器是可取的。本文的概念是在相界面处使用两相黎曼问题的近似解。对压缩激波的经典HLLRiemann求解器进行了扩展，引入了一个附加的中间态来区分液、汽相，并精确地求解相界面。为了得到热力学上一致的近似，采用了确定相变率的动力学模型。通过将数值结果与一维和三维框架下的精确解进行比较，验证了该近似黎曼求解器的适用性。将蒸发率与快速蒸发和沸腾实验进行了比较。然后，将两相近似黎曼解算器用于基于幽灵流体近似的具有尖锐界面分辨率的可压缩两相代码中，该数据来自这种新的近似两相黎曼求解器。对于激波-液滴相互作用，该方法以比精确解低得多的成本提供了相转移和表面张力效应的快速和准确的解析。
The sharp-interface resolution of compressible liquid–vapor flows is cumbersome due to the necessary tracking of the interface. The global dynamics are governed by local interface phenomena like surface tension effects as well as mass and energy transfer across the interface. These effects impose subtle jump conditions that have to be resolved locally at the interface. The exact solution of the two-phase Riemann problem is done by a complicated time-consuming iteration process. In addition most of the detailed knowledge of the Riemann pattern is not used in the overall algorithm such that the development of a much simpler approximative Riemann solver is desirable. The concept in this paper is to use an approximate solution of a two-phase Riemann problem at the phase interface. Extending the classical HLL Riemann solver for compressive shock waves, an additional intermediate state is introduced to distinguish between the liquid and vapor phase and to resolve the phase interface accurately. To get a thermodynamically consistent approximation a kinetic model is applied that determines the phase transition rate. The suitability of this approximative Riemann solver is validated by comparing the numerical results to the exact solution in one- and three-dimensional frameworks. The evaporation rates are compared to experiments with rapid evaporation and boiling. The two-phase approximative Riemann solver is then used in a compressible two-phase code with a sharp-interface resolution based on a ghost fluid approximation with data from this novel approximative two-phase Riemann solver. For a shock-droplet interaction this method provides a fast and accurate resolution of phase transfer and surface tension effects at much lower costs than the exact solution.