Direct simulation of subgrid turbulence in high-re, wall-bounded flows

The two level simulation (TLS) approach, baaed on the decomposition of the scales into large and small-scale components has been applied as a subgrid closure for large eddy simulation (LES) technique in order to simulate the near-wall features in high Reynolds number flows. Current LES approaches use eddy viscosity type models to evaluate the subgrid turbulence. In this proposed methodology, the subgrid turbulence is evaluated by computing the small-scale field itself rather than modeling it. The capabilities of the proposed methodology have been tested and validated for a fully developed turbulent channel flow for various Reynolds numbers. Additionally, simulation of high-Re flow past a three-dimensional bump is carried out to demonstrate the ability of this approach for complex flows. Results show that the proposed model will increase the accuracy of the LES computations without requiring a drastic Increase in computational resources.