VERY LARGE EDDY SIMULATION FOR SWIRLING FLOWS WITH APPLICATION IN HYDRAULIC MACHINERY

In this paper a new turbulence model for Very Large Eddy Simulation is presented. Its main characteristic is an adaptive filtering technique which can distinguish between numerically resolved and unresolved parts of the flow. This unresolved part is then modelled with extended k-ε model of Chen and Kim. VLES is applied to the simulation of unsteady vortex flows in a straight diffuser, a draft tube and a pipe trifurcation which usually cannot be predicted with classical turbulence models. Using the new technique, these complex phenomena are well predicted