Zonal Models of Turbulence and Their Application to Free Shear Flows

摘要

The concept of zonal modeling is tested by using three homogeneous flows. Turbulence models are constructed independently for various zones. A parameter that governs the readjustment of the flow from one zone to another is introduced. This readjustment parameter reflects the changes in physics involved in the transition process. The results of the zonal concept are very promising. The idea is then applied to the development of improved models for free shear flows. A close examination of the experimental data of various free shear flows is first performed. The standard K-epsilon model is adopted as a base model since it predicts many flows reasonably well. Zonal models for well-defined zones are constructed independently by systematically modifying the standard K-epsilon model to reflect the physics associated with the zones.