Turbulence and Heat Transfer of a Hairpin Vortex Formed Behind a Cube in a Laminar Boundary Layer

Abstract

We report numerical simulations of three-dimensional unsteady separated flow and heat transfer around a cube mounted in a laminar boundary layer. The separated shear layer rolls up and a hairpin vortex is generated periodically behind the cube. A horseshoe vortex is also formed ahead of the cube. Heat transfer around the cube is high due to the horseshoe vortex. Since the hairpin vortex interacts with horseshoe vortices downstream of the cube, the heat transfer increases around the center of the spanwise direction. The hairpin and horseshoe vortices generate local areas of high turbulence.