Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
NUMERICAL STUDY OF THE HEAT TRANSFER RATE FOR UNSTEADY GÖRTLER VORTICES
Submission Author:
Adriano Takata , SP
Co-Authors:
Adriano Takata, Leandro Franco de Souza
Presenter: Leandro Franco de Souza
doi://10.26678/ABCM.COBEM2019.COB2019-1475
Abstract
The streamwise-oriented counter-rotating vortices also known as Görtler vortices occur due to the imbalance between centrifugal and inertial forces in boundary layer flows over concave walls. This kind of vortex appears in aerodynamic flow such as turbine blades and airfoils. Recently, the study in this area is focused on the evolution of vortices when unsteady disturbances are inserted. Some conclusions in these studies are that both spanwise wavelength and the frequency number has great importance in the behavior of the Görtler vortices. The change in the behavior of the vortices should influence the heat transfer rate due to the relationship between the velocity and thermal boundary layers. Thus, the present work aims to investigate the heat transfer rate using the Direct Numerical Simulation (DNS) when unsteady disturbances are inserted from blowing and suction of mass at the wall. The steady disturbances reached the highest heat transfer rates for the wavelength in the spanwise direction 9.0 and 18.0 mm. The point where the Görtler vortices begin to intensify the heat transfer rate is further away from the leading edge when is inserted unsteady disturbances. Moreover, the dominant mode has a greater influence on the heat transfer rate.
Keywords
Unsteady Görtler vortices, Heat transfer, direct numerical simulation, Non-linear analysis
