Kinetic-Eddy Simulation of Static and Dynamic Stall

Abstract

A Kinetic-Eddy Simulation (KES) approach has been developed for large-eddy simulation (LES) of wall-bounded turbulent flow at high Reynolds numbers. The model solves for the local unresolved kinetic energy and the local subgrid length scale. The dissipation of the kinetic energy depends on the length scale, as well as on the length scale gradient. In most of flow domain of simulated cases, the subgrid length scale is of the order of the computational grid scale, and the KES approach behaves like a LES. In some other regions the length scale tends toward the integral scale and thus, smoothly approaches the very large-eddy simulation (VLES) limit. A robust KES approach is demonstrated here that employs the realizability constraints to bound the model parameters. The realizable KES has been applied to static stall around a 3D NACA0015 wing, oscillatory attached and dynamic light stall, and dynamic deep stall flows around a 2D NACA0015 airfoil. Vortex shedding and massive separation of the boundary layer at high Reynolds number are clearly captured. The behavior of the realizable KES approach on high angle-of-attack aerodynamics is studied.