Numerical simulation of jet mixing noise associated with engine exhausts

与发动机排气相关的喷射混合噪声的数值模拟

• 批准号: 5405995
• 负责人: Professor Dr.-Ing. Frank Thiele
• 金额: --
• 依托单位: Institut für Strömungsmechanik und Technische Akustik (ISTA)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2003
• 资助国家: 德国
• 起止时间: 2002-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5405995?language=en
• 关键词: Numerical; simulation; jet; mixing; noise

This project is concerned with the numerical prediction of engine exhaust noise. This topic is of particular interest because it involves many different flow features, mixing of cold and hot jet turbulent flows, free shear layers and wall bounded flows. Therefore, special numerical developments will have to be achieved in the CFD codes in order to obtain accurate estimates of the acoustic sources and their near field in subsonic jets. Several numerical approaches will be investigated and validated with other CFD partners of the project. In parallel the difficult question about the physical relevance of unsteady wall flow computations and their applicability to acoustic far field estimates will be addressed. For that purpose, an experimental benchmark from the French partner will be used. This benchmark combines a turbulent jet flow with the quasi periodic disturbance of a circular cylinder impinging on a downstream located airfoil. Thus, the problem of a wall bounded flow in the vicinity of a turbulent jet flow is addressed experimentally. Most results of this experiment are already available, but a few additional measurements will be carried out. Comparisons will be made both on the unsteady flow field and on the acoustic far field. Far field computations will be achieved by integrating the instantaneous sources terms into an advanced time formulation of the Ffwocs-Williams-Hawkings analogy.

该项目与发动机排气噪声的数值预测有关。该主题特别令人感兴趣，因为它涉及许多不同的流动特征，冷和热喷射湍流，自由剪切层和墙壁有界流的混合。因此，必须在CFD代码中实现特殊的数值发展，以便获得对声源及其在亚音速喷射中的近场的准确估计。将与该项目的其他CFD合作伙伴进行调查和验证几种数值方法。同时，将解决有关不稳定壁流量计算的物理相关性及其对声学远处估计的适用性的困难问题。为此，将使用法国合作伙伴的实验基准。该基准测试结合了湍流的流动与圆形圆柱体的准周期性干扰，撞击下游的机翼上。因此，在实验中解决了湍流流动流附近壁界流的问题。该实验的大多数结果已经可用，但是将进行一些其他测量。比较将在不稳定的流场和声学远场上进行。通过将瞬时源项集成到FFWOCS-Williams-Hawkings类比的高级时间公式中，将实现远处的现场计算。