Airfoil and blade self-noise

点击翻译按钮获取中文摘要

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.