OpenSBLI v3.0: High-fidelity multi-block transonic aerofoil CFD simulations using domain specific languages on GPUs

OpenSBLI is an automatic code-generation framework for compressible Computational Fluid Dynamics (CFD) simulations on heterogeneous computing architectures (previous release: Lusher et al. (2021) [4]). OpenSBLI is coupled to the Oxford Parallel Structured (OPS) Domain Specific Language (DSL), which uses source-to-source translation to enable parallel execution of the code on large-scale supercomputers, including multi-GPU clusters. To date, OpenSBLI has largely been applied to compressible turbulence and shock-wave/boundary-layer interactions on very simple geometries comprised of single mesh blocks with essentially orthogonal grid lines. OpenSBLI has been extended in this new release to target strongly curvilinear cases, including transonic aerofoils using multi-block grids. In addition to multi-block mesh support, more efficient numerical shock-capturing methods and filters have been added to the codebase. Improvements to post-processing, reduced-dimension data output, and coupling to a modal decomposition library are also included. A set of validation cases are presented to showcase the new code features. Furthermore, state-of-the-art wide-span transonic aerofoil simulations on up to N = 2.5 x 10^9 grid points demonstrate that wider aspect ratios can alter buffet predictions and increase the regularity of the low-frequency shock oscillations by accommodating fully-developed trailing edge flow separation. Spectral Proper Orthogonal Decomposition (SPOD) analysis showed that overly-narrow aerofoil simulations contain additional domain-dependent energy content at a Strouhal number of St ≈ 3 associated with wake modes.

OpenSBLI是一款针对异构计算架构上进行可压缩计算流体动力学（CFD）模拟的自动代码生成框架（前版：Lusher等，2021 [4]）。OpenSBLI与牛津并行结构（OPS）领域特定语言（DSL）相耦合，该语言通过源到源的翻译实现代码在大型超级计算机上的并行执行，包括多GPU集群。迄今为止，OpenSBLI主要应用于对非常简单的几何形状，即由单网格块组成且网格线基本正交的几何形状上的可压缩湍流和激波/边界层相互作用。在本新版本中，OpenSBLI已扩展以针对强曲率情况，包括使用多块网格的跨音速翼型。除了多块网格支持外，代码库中还增加了更有效的数值激波捕捉方法和滤波器。还包括了后处理改进、降维数据输出以及与模态分解库的耦合。提供了一系列验证案例以展示新的代码功能。此外，基于高达N = 2.5 x 10^9网格点的最先进宽频跨音速翼型模拟，证明了较大的宽高比可以改变颤振预测，并通过容纳充分发展的后缘分离流动来增加低频激波振荡的规律性。频谱正交分解（SPOD）分析表明，过窄的翼型模拟在斯特劳哈数St ≈ 3处包含额外的域相关能量含量，这与尾流模式相关。