Evolution Of Hairpin Vortices In A Shear Flow

Download or read book Evolution of Hairpin Vortices in a Shear Flow written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-03 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent experimental studies suggest that the hairpin vortex plays an important (and perhaps dominant) role in the dynamics of turbulent flows near walls. In this study a numerical procedure is developed to allow the accurate computation of the trajectory of a 3-D vortex having a small core radius. For hairpin vortices which are convected in a shear flow above a wall, the calculated results show that a 2-D vortex containing a small 3-D disturbance distorts into a complex shape with subsidiary hairpin vortices forming outboard of the original hairpin vortex. As the vortex moves above the wall, it induces unsteady motion in the viscous flow near the wall: numerical solutions suggest that the boundary-layer flow near the wall will ultimately erupt in response to the motion of the hairpin vortex and in the process a secondary hairpin vortex will be created. The computer results agree with recent experimental investigations. Hon, T.-L. and Walker, J. D. A. Glenn Research Center NASA ORDER C-99066-G; RTOP 505-62-21...