论文标题
求解CFD中泊松方程的技术的比较
A comparison of techniques for solving the Poisson equation in CFD
论文作者
论文摘要
CFD是一种无处不在的技术，是许多计算模拟的核心，例如飞机设计所需的技术。泊松方程的求解经常发生在CFD中，并且有许多可能的方法可能会利用。 MONC大气模型的动态核心是CFD的一个示例，它需要解决泊松方程以确定压力项。传统上，该模型的这一方面非常耗时，因此重要的是要考虑如何降低运行时成本。 在本文中，我们调查了MONC中实施的不同方法以执行压力解决方案。旨在利用大规模，现代的HPC机器，我们关注可用技术的计算和通信行为，在本文中，我们关注直接的FFT和间接迭代方法。除了描述这些技术的实现外，我们还可以在32768个处理器内核上说明了我们方法的性能和可扩展性。原始运行时并不是唯一的措施，因此我们还对解决方案的稳定性和准确性发表了一些评论。这项工作的结果是许多技术，可针对大型HPC系统进行了优化，并且在不同情况下最合适的理解。
CFD is a ubiquitous technique central to much of computational simulation such as that required by aircraft design. Solving of the Poisson equation occurs frequently in CFD and there are a number of possible approaches one may leverage. The dynamical core of the MONC atmospheric model is one example of CFD which requires the solving of the Poisson equation to determine pressure terms. Traditionally this aspect of the model has been very time consuming and-so it is important to consider how we might reduce the runtime cost. In this paper we survey the different approaches implemented in MONC to perform the pressure solve. Designed to take advantage of large scale, modern, HPC machines, we are concerned with the computation and communication behaviour of the available techniques and in this text we focus on direct FFT and indirect iterative methods. In addition to describing the implementation of these techniques we illustrate on up to 32768 processor cores of a Cray XC30 both the performance and scalability of our approaches. Raw runtime is not the only measure so we also make some comments around the stability and accuracy of solution. The result of this work are a number of techniques, optimised for large scale HPC systems, and an understanding of which is most appropriate in different situations.
