Mathematical Modelling and Computational Engineering Prediction of Turbomachinery Broadband Noise

想飞的人逐年增加，导致地面噪音污染严重。为了解决这个问题，我们需要更好地了解飞机发动机内部噪声的来源，并能够在发动机仍在设计时预测噪声。该方案涉及最大的噪声源之一，即来自旋转风扇的尾流与下游出口导叶（OGVs）之间的相互作用。我们的主要目标是使用数学分析和计算流体动力学（CFD）的混合思想来产生基于CFD的预测方法。本研究的各个阶段将必然包括：研究通过介入的旋流从风扇中脱落的湍流的畸变，包括基于几何的模型和大规模计算之间的比较;研究这些畸变涡流和OGV之间的相互作用产生的噪声;以及由此产生的噪声在机器上游和下游的传播。我们将与英国领先的航空发动机制造商罗尔斯·罗伊斯密切合作，特别是将大量使用两家公司的主要计算机代码。我们的目标是产生一个准确的预测方法和物理见解，这可以在以后的发动机设计中应用。

The number of people wanting to fly increases year after year, leading to serious noise pollution on the ground. To solve this problem we need to better understand the sources of this noise inside the aircraft engines, and to be able to predict the noise while the engine is still being designed. This proposal is concerned with one of the biggest noise sources, which is the interaction between the wakes from the rotating fan and the downstream Outlet Guide Vanes (OGVs).Our key aim is to use a mixture of ideas from mathematical analysis and Computational Fluid Dynamics (CFD) to produce a CFD-based prediction method. Stages in this research will necessarily include: study of the distortion of turbulence shed from the fan by the intervening swirling flow, including comparison between mathematically-based models and large-scale computation; investigation of the noise generation by the interaction between these distorted eddies and the OGVs; and the propagation of the resulting noise upstream and downstream in the machine. We will work closely with the UK's leading aeroengine manufacturer, Rolls-Royce, and in particular much use will be made of the Companies' main computer code. We aim to produce an accurate prediction method and physical insight, which can later be applied in engine design.