Reciprocal Interactions of Hairpin-Shaped Vortices and a Boundary Layer.
Abstract
The role of hairpin vortices in cyclic production of wall turbulence has been studied in many laboratory experiments, primarily by using flow visualization. Study of hairpin vortices in a fully turbulent environment is greatly complicated by the presence of jitters and other co-existing structures. A viable approach for obtaining better understanding of the role of hairpin vortices in turbulence dynamics is to study the flow events stimulated by synthetically generated hairpin vortices in initially laminar boundary layers. This study simulates the flow dynamics stimulated by hairpin-shaped vortices in a boundary layer through the solution of time-dependent, three-dimensional, compressible Navier-Stokes equations. The numerical scheme used leads to temperal-spatial simulations and could be easily applied to future simulations focusing upon the effects of pressure gradient and compressibility on turbulence structure. Two simulations were carried out. In the first case, the initial condition contains only one imposed hairpin-shaped vortex; in the second, there are two incipient vortices separated by a short distance in the streamwise direction. Organized flow events; Three dimensional flow. (jes)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 1988
- Accession Number
- ADA206980
Entities
People
- H. Mcdonald
- N. S. Liu
- S. J.. Shamroth