Large-Eddy Simulations of turbulent hydrodynamic and magnetohydrodynamic channel flows

We perform Large-Eddy Simulations of incompressible hydrodynamic and magnetohydrodynamic channel flows at low magnetic Reynolds numbers (i.e. in the framework of the quasi-static approximation where the Lorentz force is treated as an explicit contribution to the momentum balance). The computations are performed using a pseudospectral and a second-order collocated finite volume method. Two eddy-viscosity type models are compared for different mesh resolutions: the dynamic Smagorinsky (DSM) and the Wall-Adapting Local Eddy-viscosity (WALE) model. We examine in detail the contributions to the kinetic energy budget of each term appearing in the Navier-Stokes equations. In particular, the results show that the subgrid-scale dissipation measured in the finite volume simulations is systematically much lower than in the spectral ones.