Airfoil and Bluff-body Noise

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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.