Numerical investigation of aircraft landing gear noise

Abstract

Aircraft noise is considered one of the most important issues of aviation environmental impact and efforts towards noise reduction are of paramount importance since regulations have become increasingly stringent in order to limit noise levels. In past decades, significant jet noise reduction has been achieved due to the design of more efficient and quieter turbofan engines. Hence, airframe noise, which is associated with the unsteady turbulent flow around the aircraft, has become a significant source of noise, especially at landing configurations. However, reduction of airframe noise is a complex task since its generation may be intrinsically related to the aircraft aerodynamics and structures, such that changes in the high lift system or in the landing gear may impose severe aerodynamic and structural penalties which cannot be overcome. Therefore, improving prediction techniques for airframe noise generation and propagation is a key topic in aeroacoustic research. In this work, we focus on high-fidelity numerical simulations of turbulent flows past nose landing gears. An important research topic in this subject is the assessment of noise sources through advanced post-processing techniques and flow modal decomposition. With the knowledge of how noise is generated in complex geometries, it will be possible to develop strategies and techniques for its reduction. Here, we envision to develop and apply numerical methods to set the best-practices in terms of noise assessment in complex landing gear geometries. Hence, we will investigate aspects related to high-fidelity turbulent flow simulations, techniques for the identification of noise sources in turbulent flows and methodologies of aeroacoustic prediction. (AU)