A fully coupled hybrid computational aeroacoustics method on hierarchical Cartesian meshes
A fully coupled hybrid computational aeroacoustics method on hierarchical Cartesian meshes
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DOI：
10.1016/j.compfluid.2016.12.001
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发表时间：
2017-02-02
影响因子：
2.8
通讯作者：
Schroeder, Wolfgang
中科院分区：
文献类型：
--
作者：
Schlottke-Lakerriper, Michael;Yu, Hans;Schroeder, Wolfgang
计算流体动力学(CFD)-计算空气声学(CAA)混合格式是空气声学模拟的标准方法。这种方法需要在CFD和CAA步骤之间交换信息，这通常通过存储声源数据来完成。然而，当这种混合方法用于具有0(109)个自由度的大规模问题时，这种数据交换过程提出了两个问题：一方面，所需的磁盘空间变得很大，并且对于单个模拟来说达到了数百TB。另一方面，整个数值方案的并行可伸缩性受到可用I/O带宽的限制，可用I/O带宽通常在5,000到10,000个核之间达到峰值。为了避免这些问题，提出了一种高度可扩展的直接混合方案，其中流动模拟和声学模拟同时运行。也就是说，两个求解器之间的所有数据都在内存中传输，从而避免了I/O子系统的限制。这两个解算器在联合分层笛卡尔网格上运行，从而实现高效的并行化和动态负载平衡，并内在地支持局部网格细化。为了验证新方案的性能，计算了同向旋涡对的气动声场。结果表明，直接-混合法能够有效地预测声压场，适合于高度并行模拟。此外，与通过磁盘I/O进行数据交换的混合方法相比，该方法在扩展到数千个核时表现出更好的性能。(C)2016爱思唯尔有限公司。保留所有权利。
Hybrid computational fluid dynamics (CFD) - computational aeroacoustics (CAA) schemes are the standard method for aeroacoustics simulations. This approach requires the exchange of information between the CFD and the CAA step, which is usually accomplished by storing acoustic source data. This data exchange procedure, however, poses two problems when such hybrid methods are used for large-scale problems with 0(109) degrees of freedom: On the one hand, the required disk space becomes large and reaches hundreds of terabytes for a single simulation. On the other hand, the parallel scalability of the overall numerical scheme is limited by the available I/O bandwidth, which typically peaks between 5,000 and 10,000 cores. To avoid these problems, a highly scalable direct-hybrid scheme is presented, in which both the flow and the acoustics simulations run simultaneously. That is, all data between the two solvers is transferred in-memory, avoiding the restrictions of the I/O subsystem. Both solvers operate on a joint hierarchical Cartesian grid, which enables efficient parallelization and dynamic load balancing and inherently supports local mesh refinement. To demonstrate the capabilities of the new scheme, the aeroacoustic field of a co-rotating vortex pair is computed. The results show that the direct-hybrid method is able to efficiently predict the acoustic pressure field and that it is suitable for highly parallel simulations. Furthermore, in comparison to the hybrid method with data exchange via disk I/O, the novel approach shows superior performance when scaling to thousands of cores. (C) 2016 Elsevier Ltd. All rights reserved.