ABSTRAKT

A reformulation of the Large Eddy Simulation (LES) equations is presented, based on an alternative decomposition of the subgrid stress tensor leading to a modified Leonard term, which becomes an integral part of the LES equations. This formulation clearly emphasizes the difference between Reynolds Average Navier-Stokes (RANS) models and LES. The reformulated LES model is tested on several well-established flows, such as jet flows, channel flows and the flow past a circular cylinder and a prolate spheroid, and the results are compared with results from conventional LES and data. For the simpler cases at lower Re-number, the differences between the models are small, while on the more complicated cases at higher Re-number, the proposed model shows improved behaviour as compared to the conventional LES model.