On the nonlinear evolution of Gortler vortices by the presence of pressure gradient

J. K. Rogenski¹; J. M. Floryan²; L. F de Souza¹

¹ Universidade de São Paulo; ² The University of Western Ontario

doi:10.20906/CPS/COB-2015-1864

Resumo

The laminar flow over a concave surface may undergo the turbulence state by secondary instabilities associated with the presence of longitudinal vortices known as Gortler vortices. Due to non-linearities these vortices distort the boundary layer structure by modifying the streamwise velocity component in both spanwise and normal to the wall directions. Nonlinear numerical simulation studies have been conducted to identify the role of external pressure gradient distributions in the development and saturation of the Gortler vortices. The results show that the flow with adverse pressure reaches saturation upstream in comparison with neutral and favorable pressure distribution cases. Spanwise-mean shear stress values greater than the laminar baseflow ones are observed in the transition region.

Palavras-chave: Gortler vortices; external pressure gradient ; saturation region; numerical simulation