Study of inverse problems on turbulence and aeroacoustics employing the resolvent analysis

Abstract

The understanding of mechanisms and structures present on turbulent flows is of fundamental importance in the fluid mechanics area, since such a knowledge allows, among other applications, the development of technologies to design aircraft with lower levels of drag and noise emission.The aeronautical industry pursues "green design" concepts, aligned with the increasingly restrictive environmental legislations, in order to reduce the COx emission levels generated by the burning of fossil fuels, as well as noise pollution, which mainly affects the communities neighboring the airports. Within this context, boundary-layer and jet flows are effective sources of friction drag and acoustic noise for an aircraft in flight conditions, especially during take-off and landing procedures.This post-doctoral fellowship project aims at studying aeroacoustic and turbulent flow problems using the resolvent method, in order to identify the optimal forcing terms that correspond to the most amplified responses in the flow.The beamforming technique in combination with the resolvent analysis will be employed to characterize turbulent and acoustic sources. Thus, it is intended to identify the turbulent structures that are most related to the radiated sound, as well as the main structures involved in the flow dynamics.It is expected the obtained results to contribute for to the development of both the national aeronautical industry and the scientific community.