Numerical Simulation of Violent Impinging Jet Flows with Improved SPH Method
Numerical Simulation of Violent Impinging Jet Flows with Improved SPH Method
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DOI：
10.1142/s0219876216410012
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发表时间：
2016-07
影响因子：
1.7
通讯作者：
J. Shao;S. M. Li;Moubin Liu
中科院分区：
文献类型：
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作者：
J. Shao;S. M. Li;Moubin Liu
本文提出了一种改进的光滑粒子流体动力学（SPH）方法，用于模拟剧烈水冲击射流问题。该方法在传统SPH方法的基础上进行了三方面的改进：（1）采用核梯度修正（KGC）和密度修正来提高计算精度，获得光滑的压力场;（2）采用耦合的动态固体边界处理（SBT）来消除固体边界附近的数值振荡，保证无穿透条件;（3）引入自由表面条件，通过核函数与体积的求和得到的核函数，对水射流进行了精确的描述。模拟了不同情况下剧烈冲击射流的流动。研究了撞击速度和角度对撞击的影响。结果表明，SPH方法具有很好的计算性能，可以得到精确的冲击射流形态和压力场分布。研究还发现，大气稀薄波对观测点的压力时程有很大的影响。离自由表面越近，压力时间历程衰减越快。
This paper presents an implementation of an improved smoothed particle hydrodynamics (SPH) method for simulating violent water impinging jet flow problems. The presented SPH method involves three major modifications on the traditional SPH method, (1) The kernel gradient correction (KGC) and density correction are used to improve the computational accuracy and obtain smoothed pressure field, (2) a coupled dynamic solid boundary treatment (SBT) is used to remove the numerical oscillation near the solid boundary and ensure no penetration condition, (3) a free surface condition, which is obtained from the summation of kernel function and volume, is used to describe the water jet accurately. Different cases about violent impinging jet flows are simulated. The influences of impact velocity and angles are investigated. It is demonstrated that the presented SPH method has very good performance with accurate impinging jet patterns and pressure field distribution. It is also found that the pressure time histories of observation points are greatly influenced by the rarefaction wave from surrounding air. Closer distance from free surface can lead to quicker decay of the pressure time history.