EFFICIENT COMPUTATION FOR GENERALISED FREE-SURFACE MULTI-PHASE SMOOTHED PARTICLE HYDRODYNAMICS (SPH) USING GRAPHICS PROCESSING UNITS (GPUs)

在过去的20年里，计算流体动力学（CFD）取得了巨大的进步，主要是在商业通用代码和更专业的浅层流动和波浪传播模型方面取得了重大进展。然而，复杂的、通常是高度非线性和扭曲的地表运动，例如波浪破碎、钻孔传播、通气性和碎屑运输，在很大程度上仍然难以解决。在这方面，光滑粒子流体力学（SPH）的新方法具有很大的前景。SPH是一种无网格方法，与传统的基于网格的方法相比具有一些独特的优点；没有明确的处理自由表面和没有计算网格意味着复杂的几何形状不需要复杂的网格。最近的理论进展已经在二维中得到了证明，但该方法的主要实际限制在于收敛解所需的粒子数量非常大。为了解决这个问题，高性能计算（HPC）已经在一些学术和工业研究中心（EDF, VA TECH Hydro, ESI BV）应用于3d和2d。然而，有一个最吸引人的选择，起源于电脑游戏行业，它产生了并行架构的图形处理单元（gpu），可以用于SPH。这项提议的目的是利用gpu来解决三维自由表面问题，包括剧烈和多相效应，涵盖一系列行业，如海上或海洋工程师或海军建筑师，从事洪水风险管理的土木工程师以及其他具有复杂自由表面的领域，通常是多相流，如核工业。

Great progress has been made in the last 20 years in computational fluid dynamics (CFD) with major developments in commercial general-purpose codes and more specialised shallow flow and wave propagation modelling. However, complex, generally highly nonlinear and distorted, surface motion, involving for example wave breaking, bore propagation, aeration and debris transport, has remained largely intractable. In this respect the novel method of smoothed particle hydrodynamics (SPH) holds great promise. SPH is a meshless method and possesses some unique advantages over conventional grid-based approaches; no explicit treatment of the free surface and no computational grid mean that sophisticated meshing is not needed for complex geometries. Recent theoretical advances have been proven in 2-D but the major practical limitation of the method lies in the very large number of particles required for converged solutions. To address this, High Performance Computing (HPC) has been applied in 3-D as well as 2-D in several academic and industrial research centres (EDF, VA TECH Hydro, ESI BV). There is a most attractive alternative however, originating from the computer games industry which has given rise to Graphics Processing Units (GPUs) of parallel architecture which may be exploited for SPH. The aim of this proposal is to exploit GPUs for 3-D free-surface problems, including violent and multi-phase effects, spanning a range of industries such as for offshore or marine engineers or naval architects, civil engineers undertaking flood risk management and other areas with complex free-surface, generally multi-phase flows such as in the nuclear industry.