Toward low order models of wall turbulence using resolvent analysis

Resolvent analysis for wall turbulence has the potential to provide a physical basis for both sub-grid scale and dynamic wall models for large-eddy simulations (LES), and an explicit representation of the interface between resolved and modeled scales. Toward the development of such a wall model, direct numerical simulation results are used to represent the Reynolds stresses, formulated as the nonlinear feedback (forcing) to the linear(ized) Navier-Stokes equations. It is found from direct calculation of the Reynolds stress gradients that the (solenoidal) nonlinear feedback is coherent and consistent with energetic activity that is localized in the wall-normal direction. Further, there exists a spatial organization of this forcing that is correlated with individual(large) scales. A brief outlook for LES modeling is given