Airfoil and Bluff-body Noise

本文的研究重点是低亚音速和高亚音速下的翼型和崖体噪声。这两个典型问题是未来预测大多数通风和推进系统中涉及的低速和高速风扇噪声以及高升力装置或起落架产生的机身噪声的基础。然后，提案应回应与日益增加的空中交通和嘈杂的工作条件有关的重要环境和健康问题。它应该是对舍布鲁克大学航空声学工业主席和商业主导的项目的补充，这些项目更侧重于涡轮发动机和通风系统中的噪声源，以及机身噪音。然后，它应该加强作为加拿大主要经济部门之一的运输业。它旨在发展(1)数值和分析工具来模拟和预测由流动与固体表面相互作用产生的气动声学现象，从噪声源（即发射阶段）到人类接收（即传播阶段），以及(2)创新的噪声控制概念和技术来减少这些滋扰。最终，这些预测工具和噪声控制技术将应用于系统层面，以减少来自低速和高速风扇、高升力装置和起落架的噪声。它们将被整合到设计过程中，以确保这些产品的噪音规格和新的环境法规得到满足。翼型和钝体噪声源可分为两个主要主题：自噪声和相互作用噪声，将产生音调和宽带贡献。在这两种情况下，进行了详细的可压缩非定常数值模拟，以准确预测噪声源和近场声音，并采用声学类比将该声音传播到远场。将所得结果与在开放射流消声风洞中进行的测量结果进行了比较，以验证改进的声学分析模型。

The present research proposal focuses on airfoil and bluff-body noise at low and high subsonic speed. These two canonical problems are the building blocks for the future prediction of low and high speed fan noise involved in most ventilation and propulsion systems, and airframe noise generated by high lift devices or landing gears. The proposal should then respond to important environmental and health issues related to increasing air traffic and noisy work conditions. It should be complementary to the industrial Chair in Aeroacoustics at Université de Sherbrooke and the Business-Led projects which rather focus on the noise sources in turbo-engine and ventilation systems, and on airframe noise. It should then strengthen the transportation industry that is one of the key economic sectors of Canada. It is directed towards developing (1) numerical and analytical tools to simulate and predict aeroacoustic phenomena generated by the interaction of a flow with a solid surface, from the sources of noise (i.e. the emission phase) to their reception by a human being (i.e. the propagation phase), and (2) innovative noise control concepts and technologies to reduce these nuisances. Ultimately these prediction tools and noise control techniques will be applied at the system level to reduce the noise from low and high speed fans, high lift devices and landing gears. They will be integrated in their design process to guarantee that noise specifications of these products and new environmental regulations are met. Airfoil and bluff body noise sources can be divided into two main themes: self-noise and interaction noise which will yield both tonal and broadband contributions. In both cases, detailed compressible unsteady numerical simulations are performed to predict the noises sources and the near-field sound accurately and an acoustical analogy is used to propagate this sound to the far field. The resulting results are compared with measurements performed in open-jet anechoic wind tunnels to validate the improved acoustic analytical models.