An SPH model for multiphase flows with complex interfaces and large density differences
An SPH model for multiphase flows with complex interfaces and large density differences
复制标题
复杂界面、大密度差多相流的SPH模型
DOI：
10.1016/j.jcp.2014.11.037
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发表时间：
2015-02-15
影响因子：
4.1
通讯作者：
Shu, C.
中科院分区：
文献类型：
--
作者：
Chen, Z.;Zong, Z.;Shu, C.
本文提出了一种适用于复杂界面大密度差多相流的改进SPH模型。多相SPH模型基于界面上压力连续的假设，避免了直接利用相邻颗粒的密度或质量信息求解控制方程。为了提高计算精度和获得光滑的压力场，采用了修正的密度重新初始化。一个耦合的动态固体边界处理（SBT）的实施，以减少数值振荡，并防止非物理粒子渗透的边界区域。针对多相流模拟中流体界面上密度不连续的情况，对密度校正和耦合动力学SBT算法进行了改进。粒子密度的截止值被设置为避免负压，这可能导致严重的数值困难，甚至可能终止模拟。三个有代表性的数值算例，包括瑞利-泰勒不稳定性试验，非Boussinesq问题和溃坝模拟，并与分析结果或实验数据进行比较。结果表明，SPH模型能够模拟具有较大界面变形和密度比的复杂多相流。(C)2014 Elsevier Inc. All rights reserved.
In this paper, an improved SPH model for multiphase flows with complex interfaces and large density differences is developed. The multiphase SPH model is based on the assumption of pressure continuity over the interfaces and avoids directly using the information of neighboring particles' densities or masses in solving governing equations. In order to improve computational accuracy and to obtain smooth pressure fields, a corrected density re-initialization is applied. A coupled dynamic solid boundary treatment (SBT) is implemented both to reduce numerical oscillations and to prevent unphysical particle penetration in the boundary area. The density correction and coupled dynamics SBT algorithms are modified to adapt to the density discontinuity on fluid interfaces in multiphase simulation. A cut-off value of the particle density is set to avoid negative pressure, which can lead to severe numerical difficulties and may even terminate the simulations. Three representative numerical examples, including a Rayleigh-Taylor instability test, a non-Boussinesq problem and a dam breaking simulation, are presented and compared with analytical results or experimental data. It is demonstrated that the present SPH model is capable of modeling complex multiphase flows with large interfacial deformations and density ratios. (C) 2014 Elsevier Inc. All rights reserved.