A fluid simulation system based on the MPS method

Fluid flow simulation is a highly active area with applications in a wide range of engineering problems and interactive systems. Meshless methods like the Moving Particle Semi-implicit (MPS) are a great alternative to deal efficiently with large deformations and free-surface flow. However, mesh-based approaches can achieve higher numerical precision than particle-based techniques with a performance cost. This paper presents a numerically stable and parallelized system that benefits from advances in the literature and parallel computing to obtain an adaptable MPS method. The proposed technique can simulate liquids using different approaches, such as two ways to calculate the particles’ pressure, turbulent flow, and multiphase interaction. The method is evaluated under traditional tests cases presenting comparable results to recent techniques. This work integrates the previously mentioned advances into a single solution, which can switch on improvements, such as better momentum conservation and less spurious pressure oscillations, through a graphical interface. The code is entirely open-source under the GPLv3 free software license. The GPU-accelerated code reached speedups ranging from 3 to 43 times, depending on the total number of particles. The simulation runs at one fps for a case with approximately 200,000 particles.

流体流动模拟是极具活力的前沿研究领域，其应用覆盖各类工程问题与交互系统场景。诸如移动粒子半隐式法（Moving Particle Semi-implicit, MPS）这类无网格方法，是高效处理大变形与自由表面流动的优质替代方案。不过，基于网格的方法虽可实现比基于粒子的技术更高的数值精度，但会带来性能开销。本文提出了一种数值稳定且支持并行化的系统，其依托现有研究进展与并行计算技术，构建出可灵活适配多种场景的MPS方法。所提出的技术可通过多种方案实现流体模拟，例如两种粒子压强计算方式、湍流流动模拟以及多相相互作用模拟。该方法通过经典测试用例进行验证，其模拟结果与当前主流技术表现相当。本研究将前述各项技术进展整合为一套统一解决方案，可通过图形化界面启用多项优化功能，例如提升动量守恒性、抑制伪压强振荡等。该代码完全遵循GPLv3自由软件许可证，全部开源。经GPU加速的代码可实现3至43倍的加速比，具体加速倍数取决于粒子总数量。在包含约20万个粒子的测试场景中，模拟帧率可达1帧每秒。