Interaction between wavepackets generated by pontual sources in a compressible boundary layer

Abstract

This research project aims to study the transition phenomenon due to the interaction between two point sources of disturbance inserted into a flat plate. Transition is a fairly complex process and is not yet fully understood, so that the theories already developed not well describe the phenomenon as it occurs in nature. The transition phenomenon has been studied since the nineteenth century and has theoretical explanation in very controlled situations. Its onset is linked to the presence of disturbances in the velocity field that, when in an appropriate frequency can be amplified by the flow resulting after a nonlinear process, the turbulent flow. Studies indicate that natural transition can be better modeled as effect of wavepacket of three-dimensional modulated wave, a much more complex situation than the case of the few flat and monochromatic waves for which the theory holds. The complexity of the phenomenon makes it imperative to use software tool. The present study is an expansion of the results from a previous study on transition due to a point source only for the case that two point sources interact. The analysis of the case is performed using a previously developed code that solves the Navier-Stokes equations by means of direct numerical simulation (DNS). The analysis of results will be made both in physical space and in Fourier space, allowing you to compare the spectral content of the disturbances and compare with the case of only a point source.