Resolvent analysis predictions of energy transfer in turbulent channel flow

Abstract

We analyse the inter-scale transfer of energy for turbulent channel flow at Reτ = 180 in a minimal flow unit. The dominant energy-producing modes are streamwise-constant streaks with a spanwise spacing of approximately 100 wall units. Since the viscous dissipation for these scales is not sufficient to balance production, the nonlinear terms redistribute the excess energy to other scales. We compare the energy balance to predictions from resolvent analysis and show that it does not model energy transfer well. Nevertheless, we find that the energy transferred from the streamwise-constant streaks can be predicted reasonably well by a Cess eddy viscosity profile. As such, eddy viscosity is an ef..