Exploring the Flow Around a Simplified Bus with Large Eddy Simulation and Topological Tools

The results of the large eddy simulation of the flow around a simplified bus presented in Krajnovic and Davidson (Journal of Fluids Engineering,125, pages 500-509, 2002) are used to describe this flow in detail. Using time-averaged trace lines on the surface of the body, the patterns of the shear-stress lines are revealed and used to identify bifurcation lines and critical points (zero-shear-stress points) in the flow. This information is then used to establish a complete picture of the flow on the surface of the body that can be used for understanding soiling and accumulation of water on the surface or in determinations of aeroacoustic noise sources. Kinematical investigations of the flow in two symmetry planes were done to reveal the critical points in the flow. With this it was proven that the flow resulting from numerical simulation is kinematically possible