Investigation of noise generation and propagation by aerodynamic configurations using computational aeroacoustics

Abstract

Noise regulations have become incrementally more stringent as air traffic has increased and will likely continue to do so in the future. In the last three decades, significant jet noise reduction has been achieved due to efforts on the design of more efficient and quieter engines. Since then, airframe noise associated with the unsteady flow around the aircraft has become a significant source of noise, especially for landing configurations. Therefore, the investigation of airframe noise generation and propagation is a key topic in aeroacoustics research. The present work concerns the study of aerodynamic noise generation and propagation using numerical methods specially designed for computational aeroacoustics. In this project, we will primarily investigate fundamental noise generation mechanisms either due to a single airfoil or due to multiple aerodynamic configurations where wake and boundary layer interactions occur. This study is of paramount importance for the design of aerodynamic configurations such as wings and high-lift devices, as well as gas turbine blades and wind turbine blades, fans and propellers. Some aspects of aerodynamic noise generation and propagation not covered, or not fully understood, in the literature will be addressed in this work. The unsteady aerodynamic flows analyzed give rise to noise sources at a broad range of frequencies and spatial scales. Therefore, direct numerical simulation (DNS) is the numerical method of choice for the flow simulations since it captures all the energetic scales associated with noise generation and propagation. The aeroacoustic calculations will be performed using DNS and the Ffowcs Williams & Hawkings (FWH) acoustic analogy formulation. (AU)