Airfoil and blade self-noise

目前的研究建议集中在翼型和叶片噪声在低（亚音速）和高（跨音速）的速度。这些典型问题是任何运输系统（包括自动驾驶汽车或无人机）噪声预测的基础。例如，它将直接有助于预测和控制大多数通风和推进系统中涉及的低速和高速风扇噪声，以及由增升装置或尾翼产生的机体噪声。然后，该提案应回应与空中交通量增加、自动驾驶汽车扩散和噪音工作条件有关的重要的当前和未来环境和健康问题。它应该是对舍布鲁克大学航空声学工业主席和合作研究项目的补充，这些项目侧重于实际涡轮发动机和通风系统中完整噪声源的预测和控制，以及机身噪声。然后，它应该加强作为加拿大关键经济部门之一的运输业，并帮助国防部检测和打击自动驾驶汽车。它还将通过帮助电动汽车的认证和验收来减少温室气体排放，对于电动汽车来说，加热问题增加了冷却需求，从而增加了通风需求。本研究建议旨在开发（1）数值和分析工具，以模拟和预测气流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，以减少这些滋扰。最终，这些预测工具和噪声控制技术将应用于系统层面，以降低低速和高速风扇、高升力设备和自动驾驶汽车的噪声。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。翼型噪声源产生音调和宽带的贡献，可以预测详细的可压缩非定常数值模拟在近场准确地传播到远场的声学类比。结果进行了比较，在开放式射流消声风洞中进行的测量，以验证改进的声学分析模型。

The present research proposal focuses on airfoil and blade noise at low (subsonic) and high (transonic) speeds. These canonical problems are the building blocks for the noise prediction of any transport system including autonomous vehicles or drones. For instance it will directly contributes to the prediction and control of low and high speed fan noise involved in most ventilation and propulsion systems, as well as airframe noise generated by high lift devices or empennages. The proposal should then respond to important present and future environmental and health issues related to increasing air traffic, proliferation of autonomous vehicles and noisy work conditions. It should be complementary to the industrial Chair in Aeroacoustics at Université de Sherbrooke and the Collaborative Research projects which rather focus on the prediction and control of the full noise sources in the actual 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 and help the Department of National Defense to detect and counter autonomous vehicles. It will also yield a reduction of greenhouse gas emissions by helping the certification and acceptation of electrical cars for which heating issues increase the cooling demands and consequently the ventilation needs. This research proposal 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 autonomous vehicles. They will be integrated in their design process to guarantee that noise specifications of these products and new environmental regulations are met. Airfoil noise sources yield both tonal and broadband contributions that can be predicted by detailed compressible unsteady numerical simulations in the near-field accurately and propagated to the far field by an acoustical analogy. The resulting results are compared with measurements performed in open-jet anechoic wind tunnels to validate the improved acoustic analytical models.