Accelerating Manycore Fluid Flow Predictions Including Wave/Ship Motions Using Parareal

亿级高性能计算趋势表明，未来将以低成本获得大量计算资源，但需要新的软件设计和并行化策略来充分利用这些新兴的多核硬件系统。在过去的六年里，申请人领导开发了名为EXN/Aero的多核计算流体动力学(CFD)代码，该代码现在显示出(使用GPU)与通过空间域分解获得的传统CPU解决方案相比，显著加快了求解速度。EXN/Aero的开发还包括一种称为Parareal的组合时空并行计算方法。在这里，域分解包括空间和时间，是亿级计算中的一个新兴研究领域，因为它提供了一种在高度并行的应用程序受内存限制时减少计算时间的方法。然而，对于高雷诺数和多物理CFD应用，有必要改进方法。拟议研究的首选应用领域是环境和船舶/海底海洋流动领域。在这些地区建立一套高效的三维非定常湍流CFD模型对于全面的声源建模，包括随后输入到广泛的特征研究中是重要的。申请者已经与加拿大国防研究和发展公司合作多年的潜艇项目(开发包括EXN/AERO在内的一系列CFD模拟能力)，因此将其扩展到舰船是很自然的。特别是，该提案将侧重于开发船舶模拟的辅助方法的目标，其中包括波浪、船舶运动和推进(包括空泡)的重要耦合。所有这些方面结合在一起，对于预测产生噪声源的高度湍流流动环境是很重要的。这项研究将使加拿大工业和政府能够利用未来的CFD超级计算技术，这些技术将对开发船舶和潜艇平台等复杂系统以及潮汐能源开发等环境流至关重要。

Exascale high-performance computing trends point to substantial computing resources at a low cost moving into the future, but new software designs and parallelization strategies are required to take full advantage of these emerging manycore hardware systems. Over the past six years, the applicant has led the development of a manycore Computational Fluid Dynamics (CFD) code called EXN/Aero that is now demonstrating significant solution speed-up (using GPUs) versus traditional CPU solutions obtained with spatial domain decompositions. The EXN/Aero development has also included a combined space-time parallel computing approach called parareal. Here, the domain decomposition includes both space and time, and is an emerging research area in exascale computing since it provides a way to reduce computing time when a highly parallel application is memory-bound. There is, however, a need to refine the methodology for high-Reynolds number and multi-physics CFD applications. The applications of choice for the proposed research is in the area of environmental and ship/submarine ocean flows. Building an efficient set 3D unsteady turbulent flow CFD models in these areas is important for comprehensive acoustic source modeling, including subsequent input into a wide range of signatures studies. The applicant has worked for a number of years with Defense Research and Development Canada on their submarine program (developing a range of CFD simulation capabilities including EXN/Aero) and the extension to ships is therefore a natural one. In particular, the proposal will focus on objectives that develop the parareal method for ship simulations that include the important couplings of waves, ship motion and propulsion (including cavitation). All of these aspects are important, when coupled, to predicting the highly turbulent flow environment from which noise sources arise. The research will allow Canadian industry and government to tap into future CFD supercomputing technologies which will be essential to developing complex systems such as ship and submarine platforms, and environmental flows such as that for tidal energy development.