Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
RECEPTIVITY OF ACOUSTIC WAVES ON LOCALIZED ROUGHNESS IN COMPRESSIBLE LAMINAR BOUNDARY LAYERS
Submission Author:
Pedro Henrique Rosa dos Santos , DF
Co-Authors:
Pedro Henrique Rosa dos Santos, Fernando H T Himeno, Marlon Sproesser Mathias, Marcello Augusto Faraco de Medeiros
Presenter: Pedro Henrique Rosa dos Santos
doi://10.26678/ABCM.COBEM2021.COB2021-1978
Abstract
Surface imperfections, such as roughnesses, can affect the laminar-turbulent transition process in boundary layers. One main engineering objective is predicting the initial amplitude of instability waves, which is a function of the flow’s receptivity to external disturbances. Existing theories about receptivity are limited to restricted flow regimes and semi-empirical relations are commonly used in industry. In this context, this paper investigates the receptivity of the scattering of one-dimensional acoustic waves on roughness located in a flat plate boundary layer. To do so, this work carried out high-order DNS simulations of a roughness inserted in a flat plate boundary layer. A sinusoidal velocity perturbation with constant frequency was superimposed on the inflow contour of the base flow. The Tollmien Schilichting wave is obtained by the difference between the unsteady fluctuation of the cases with and without roughness. The data is compared with recent experiments and the numerical uncertainty is quantified.
Keywords
Receptivity, Laminar-turbulent transition, DNS, Tollmien-Schlichting waves
