Abstract The use of a CFD/CAA method, where fluctuations are extracted on a surface and propagated analytically to the far-field, is becoming a practical approach for industrial jet noise prediction. However, the placement of the surface can be problematic and a source of error, so here an efficient LES/APE coupling method that relies on volumetric sources is utilised. This allows the use of an existing, well validated and robust finite volume LES code to compute the unsteady flow, from which the volumetric sources are extracted, to then compute the propagation of the acoustic waves to the far-field using a high-order finite element APE code with a grid more appropriate for this task. Furthermore, this coupled methodology allows the studying of noise propagation in complex configurations in which the use of surface integral methods could be challenging. In this work, a coupling strategy is used in which all the necessary data is exchanged directly via the high-speed communication network using an open-source library. The efficiency of the parallel-coupling strategy is demonstrated by applying it to a 2D canonical case and comparing it with an existing file-based approach. For the acoustic propagation, the APE solver used is called AcousticSolver, part of the high-order spectral/hp finite element open-source code Nektar++. The present LES/APE framework is fist validated for 3D jet applications by studying the noise propagation of a low-Reynolds number case. Then the method is applied to a more realistic high Reynolds number jet obtaining encouraging results in terms of flow and acoustic predictions.

中文翻译：

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使用高效 LES/高阶声耦合方法进行喷射噪声分析

摘要 使用 CFD/CAA 方法，在表面上提取波动并分析传播到远场，正在成为工业喷气噪声预测的实用方法。然而，表面的放置可能会出现问题并且是错误的来源，因此这里使用了一种依赖于体积源的高效 LES/APE 耦合方法。这允许使用现有的、经过充分验证且稳健的有限体积 LES 代码来计算不稳定流，从中提取体积源，然后使用高阶有限元计算声波到远场的传播带有网格的元素 APE 代码更适合此任务。此外，这种耦合方法允许研究复杂配置中的噪声传播，其中使用表面积分方法可能具有挑战性。在这项工作中，使用了一种耦合策略，其中使用开源库通过高速通信网络直接交换所有必要的数据。通过将其应用于 2D 规范案例并将其与现有的基于文件的方法进行比较，证明了并行耦合策略的效率。对于声传播，使用的 APE 求解器称为 AcousticSolver，是高阶谱/hp 有限元开源代码 Nektar++ 的一部分。通过研究低雷诺数情况下的噪声传播，目前的 LES/APE 框架首先针对 3D 喷射应用进行了验证。