Analysis of relaxation regularization as subgrid-scale model for large-eddy simulation

We connect the eddy-viscosity concept employed in the eddy-damped quasi-normal Markovian (EDQNM) theory of turbulence with the relaxation-term concept which is being used with great success in the approximate deconvolution model (ADM) for large-eddy simulation. We present a representation of the eddy viscosity v(e) in terms of a relaxation-term formulation with optimized filter kernel. Subgrid-scale modeling properties of the relaxation regularization are assessed for forced isotropic turbulence at high Reynolds number. We also propose a new formulation of the relaxation regularization where the inverse relaxation time scale is derived from theory.