Eventos Anais de eventos
ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
TOWARDS A QUALITATIVE CRITERIA FOR THE ONSET OF ABSOLUTE INSTABILITY ON REVERSED-FLOW BOUNDARY-LAYER PROFILES
Submission Author:
Mateus Avanci , RJ
Co-Authors:
Mateus Avanci, Daniel Rodriguez, Leonardo Santos de Brito Alves
Presenter: Mateus Avanci
doi://10.26678/ABCM.ENCIT2018.CIT18-0233
Abstract
Absolute instability of boundary-layer velocity profiles featuring a region of reversed flow, typical of laminar separation bubbles on flat plates, is a possible route to the onset of self-sustained oscillations and vortex shedding. The critical conditions for the appearance of absolute instability have been widely studied in the literature in terms of the ratio of the peak reversed flow with the free-stream velocity, but results also suggest that the wall-normal extent of the recirculating flow and the location of the inflection point can be of importance. This work aims at proposing a qualitative criterion for the onset of absolute instability, that depends only on the relative locations of the inflection point and the separation line.
Keywords
Laminar separation bubble, Boundary layer separation, Absolute/convective instability instability
