Very Large Eddy Simulation for the Prediction of Unsteady Vortex Motion

A new turbulence model for Very Large Eddy Simulation, based on the extended k-e model of Chen and Kim is developed and presented in this paper. Introducing an adaptive filtering technique, the model can distinguish between numerically resolved and unresolved parts of flow. It is applied to the simulation of unstable vortex motion in a pipe trifurcation. This flow phenomenon cannot be predicted with classical RANS methods and commonly used turbulence models. Using the VLES method with the new turbulence model, the phenomenon is well predicted and the results agree reasonably well with measurement data.