Explicit small-scale velocity simulation for high-Re turbulent flows
A new approach, two level simulation (TLS), is developed based on the explicit reconstruction of the small-scale velocity by solving the small-scale governing equations on the domain with reduced dimension representing a collection of one-dimensional lines embedded in the three-dimensional flow domain. A coupled system of equations, that is not based on an eddy-viscosity hypothesis, is derived based on the decomposition of flow variables into the large-scale and the small-scale components without introducing the concept of filtering. Simplified treatment of the small-scale equations is proposed based on neglecting the small-scale advective and dissipative terms in the line orthogonal directions. Fully coupled simulation of the forced isotropic turbulence at Re??65, 114 demonstrates potential benefits and challenges of the TLS approach for high-Re turbulent flows using coarse grids.
turbulent flows large eddy simulation subgrid-scale modeling