A GPU based compressible multiphase hydrocode for modelling violent hydrodynamic impact problems
A GPU based compressible multiphase hydrocode for modelling violent hydrodynamic impact problems
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DOI：
10.1016/j.compfluid.2015.07.010
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发表时间：
2015-10
影响因子：
2.8
通讯作者：
Zhihua Ma;D. Causon;L. Qian;H. Gu;C. Mingham;P. M. Ferrer
中科院分区：
文献类型：
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作者：
Zhihua Ma;D. Causon;L. Qian;H. Gu;C. Mingham;P. M. Ferrer
本文提出了一种基于GPU的可压缩多相流体程序，用于模拟在诸如砰击和水下爆炸等恶劣条件下的剧烈水动力冲击。努力扩展一维五方程简化模型（Kapila等人，2001）在现代图形硬件上计算三维流体动力学冲击问题。为了处理自由表面的问题，如水波，重力项，这是最初从原始模型中缺席，现在被认为是包括在控制方程。一个三阶有限体积为基础的MUSCL格式离散的积分形式的控制方程。通过HLLC近似黎曼求解器的网格单元面的数值通量估计。串行CPU程序首先通过OpenMP编程模型在多核CPU上并行化，然后使用CUDA C编程语言在多核图形处理单元（GPU）上进一步加速。为了在多核和众核处理器上平衡内存使用、计算效率和精度，实现了单精度和双精度浮点运算的混合。最重要的数据，如保守的流量变量是用双精度动态数组处理，而所有其他变量/数组，如通量，残差和源项是在单精度处理。利用该方法计算了水-气激波管、一维液体空泡管、溃坝、平面刚性壁附近二维圆柱水下爆炸、刚性圆柱容器中三维球形爆炸和三维刚性平板入水等几种基准试验情况。所得结果与实验、精确解及其它独立的数值计算结果吻合良好。这表明本方法不仅能够处理剧烈的自由表面冲击问题，而且能够处理与水下爆炸相关的船体气穴现象。性能分析表明，数值模拟的运行时间成本显着降低了使用GPU的电能消耗比CPU少得多。
This paper presents a GPU based compressible multiphase hydrocode for modelling violent hydrodynamic impacts under harsh conditions such as slamming and underwater explosion. An effort is made to extend a one-dimensional five-equation reduced model (Kapila et al., 2001) to compute three-dimensional hydrodynamic impact problems on modern graphics hardware. In order to deal with free-surface problems such as water waves, gravitational terms, which are initially absent from the original model, are now considered and included in the governing equations. A third-order finite volume based MUSCL scheme is applied to discretise the integral form of the governing equations. The numerical flux across a mesh cell face is estimated by means of the HLLC approximate Riemann solver. The serial CPU program is firstly parallelised on multi-core CPUs with the OpenMP programming model and then further accelerated on many-core graphics processing units (GPUs) using the CUDA C programming language. To balance memory usage, computing efficiency and accuracy on multi- and many-core processors, a mixture of single and double precision floating-point operations is implemented. The most important data like conservative flow variables are handled with double-precision dynamic arrays, whilst all the other variables/arrays like fluxes, residual and source terms are treated in single precision. Several benchmark test cases including water-air shock tubes, one-dimensional liquid cavitation tube, dam break, 2D cylindrical underwater explosion near a planar rigid wall, 3D spherical explosion in a rigid cylindrical container and water entry of a 3D rigid flat plate have been calculated using the present approach. The obtained results agree well with experiments, exact solutions and other independent numerical computations. This demonstrates the capability of the present approach to deal with not only violent free-surface impact problems but also hull cavitation associated with underwater explosions. Performance analysis reveals that the running time cost of numerical simulations is dramatically reduced by use of GPUs with much less consumption of electrical energy than on the CPU.