Airfoil and bluff-body noise

目前的研究方案主要针对低速翼型和钝体噪声。这两个典型问题是未来预测低速风扇噪声和由高升力装置或起落架产生的机身噪声的基础。然后，该提案应响应与低速风扇噪音相关的强烈环境需求。从机身噪声的角度来看，它应该是对工业NSERC航空声学主席的补充，后者更侧重于涡轮发动机噪声源。它旨在开发(1)模拟和预测气流与固体表面相互作用产生的空气声学现象的工具，从噪声源(即发射阶段)到人类接收(即传播阶段)，以及(2)减少这些滋扰的创新噪声控制概念和技术。最终，这些预测工具和噪声控制技术将在系统层面上应用，以降低低速风扇、高升力装置和起落架的噪声。它们将被整合到他们的设计过程中，以确保这些产品的噪音规范和新的环境法规得到满足。翼型和钝体噪声源可以分为两个主要主题：自噪声和相互作用噪声，这将产生音调和宽带贡献。在这两种情况下，都进行了详细的非定常数值模拟，以准确地预测噪声源，并使用声学类比来在远场中传播声音。将计算结果与开式消声风洞的测量结果进行了比较，验证了声学分析模型的有效性。

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.