Interaction of Vorticity with a Free Surface in Turbulent Open Channel Flow
Abstract
The interaction between vorticity and a free surface, modeled as a shear free boundary is studied using a direct numerical simulation of an open channel flow at low Reynolds number. As a result of th shear free nature of the top boundary, only normal vorticity may terminater on it. The vorticity components parallel to the top boundary must go to zero as the boundary is approached. The time averaged fluctuating enstrophy balance equations, which are an indicator of the level of activity of the vorticity field are evaluated. Near the free surface the rate of production and destruction of enstrophy is set by the fluctuating velocity field. The transport of enstrophy by the fluctuating velocity has a minor role. Of the production terms, the three involving the stretching of vorticity along its axis are the most important, and a simple model explaining this is presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1991
- Accession Number
- ADA245328
Entities
People
- J. D. Swearingen
- R. A. Handler
- R. I. Leighton
- T. F. Swean Jr.
Organizations
- Leidos