Wavelet-based adaptive implicit LES/under-resolved DNS of forced isotropic turbulence

The wavelet-based adaptive implicit eddy-resolving simulation approach is demonstrated for linearly forced homogeneous isotropic turbulence at moderate Taylor-Reynolds number. The wavelet-filtered incompressible Navier-Stokes equations are solved using the adaptive multilevel wavelet collocation method for elliptic problems without employing any explicit modeling for the unclosed terms. Instead, the energy dissipation induced by the built-in low-pass filtering associated with the adaptive numerical scheme is effectively exploited, thus mimicking the effect of unresolved subgrid-scale coherent flow structures on the dynamics of the resolved ones. The results of various numerical simulations, performed at different spatial resolutions, and with different filtering strengths, prove both the feasibility and efficacy of the proposed no-model approach for wall-free turbulence, while addressing the corresponding limits of application.