Simulation of Embedded Streamwise Vortices on a Flat Plate
Abstract
Numerical simulations of a single low-profile vortex generator vane, which is only a small fraction of the boundary-layer thickness, have been performed for flows over a flat plate. The numerical simulations were computed by solving the steady-state solution to the Reynolds-averaged Navier-Stokes equations. The vortex generating vane results were evaluated by comparing the strength and trajectory of the streamwise vortex to experimental particle image velocimetry measurements. From the numerical simulations it was observed that the Shear-Stress Transport (SST) turbulence model resulted in a better prediction of the streamwise peak vorticity and trajectory when compared to the Spalart-Allmaras (SA) turbulence model. It is shown in this investigation that the estimation of the turbulent eddy viscosity near the vortex core was very high using the SA model when compared to the SST model. Even though the numerical simulations were able to predict the trajectory of the streamwise vortex, the initial magnitude and decay of the peak streamwide vorticity were significantly under predicted. A comparison of the positive circulation associated with the streamwise vortex showed that while the numerical simulations produced a more diffused vortex, that the strength of the streamwise vortex compared very well to the experimental observations. A grid resolution study was also performed showing that diffusion of the vortex was not a result of insufficient grid resolution. Comparisons were also made between a fully modeled trapemoidal vane with finite thickness to a simply modeled rectangular thin vane. These comparisons showed that the simply modeled rectangular vane produced a streamwise vortex which has a strength and trajectory very similar to the fully modeled trapezoidal vane.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2002
- Accession Number
- ADA403000
Entities
People
- Brian G. Allan
- Chung-sheng Yao
- John C. Lin