Numerical Simulation of Behavior and Heat Transfer of Hairpin Vortices Generated Around a Cube in a Laminar Boundary Layer

Abstract

This paper presents three-dimensional simulation of separated and reattached flow and heat transfer around a surface mounted cube in a laminar boundary layer. The shear layer separated at the leading edge of the cube becomes unstable, and a hairpin vortex is generated periodically. The hairpin vortex moves downstream with time and grows to the streamwise vortices stretched to the streamwise direction. The head and legs of the hairpin vortex and horseshoe vortices have great effects upon the heat transfer near the wall. The shed hairpin vortex forms alternating positive and negative fluctuations near the wall, and decreases gradually toward the downstream extending in the spanwise direction. The head of the hairpin vortex locally generates a high turbulent area at the center of the spanwise direction. Another high turbulent area across the center of the spanwise direction is generated by interference of horseshoe vortices.