Airfoil and bluff-body noise

本文的研究重点是低速时翼型和海崖体的噪声。这两个典型问题是未来预测低速风扇噪声和由增升装置或起落架产生的机体噪声的基础。然后，该提案应响应与低速风扇噪声相关的强烈环境需求。从机体噪声的角度来看，它应该是对工业NSERC航空声学主席的补充，后者侧重于涡轮发动机噪声源。其目的是开发（1）工具来模拟和预测由流动与固体表面的相互作用产生的气动声学现象，从噪声源（即发射阶段）到人类对其的接收（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级，以降低低速风扇、增升装置和起落架的噪声。它们将被集成到设计过程中，以确保这些产品的噪音规格和新的环境法规得到满足。 翼型和海崖体噪声源可以分为两个主要的主题：自噪声和相互作用噪声，这将产生音调和宽带的贡献。在这两种情况下，进行详细的非定常数值模拟，以准确地预测噪声源和声学类比是用来传播的声音在远场。结果与在开放式消声风洞中进行的测量进行比较，以验证声学分析模型。

The present research proposal focuses on airfoil and bluff body noise at low speed. These two canonical problems are the building blocks for the future prediction of low speed fan noise and airframe noise generated by high lift devices or landing gears. The proposal should then respond to strong environmental needs related to low speed fan noise. By its airframe noise perspective, it should be complementary to the industrial NSERC Chair in Aviation Acoustics, which rather focuses on the turbo-engine noise sources. It is directed towards developing (1) 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 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 unsteady numerical simulations are performed to predict the noises sources accurately and an acoustical analogy is used to propagate the sound in the far field. The resulting result is compared with measurements performed in open-jet anechoic wind tunnel to validate the acoustic analytical models.