Large Eddy Simulation of the Interaction of Homogeneous Turbulence with a Flat-Plate Cascade

Abstract

In this paper we are interested in the distortion of homogeneous isotropic turbulence as it passes through a cascade of thin ∞at plates. Spatial large eddy simulation (LES) is conducted for a linear cascade composed of six plates. Because suppression of the normal component of velocity is the main mechanism of distortion, we neglect the presence of mean shear in the boundary layers and wakes, and allow slip velocity on the plate surfaces. We only enforce the zero normal velocity condition on the plates. This boundary condition treatment is motivated by rapid distortion theory (RDT) in which viscous efiects are neglected, however the present LES approach accounts for nonlinear and turbulence difiusion efiects by a sub-grid scale model. The normal Reynolds stresses and velocity spectra are analyzed ahead, within, and downstream of the cascade. Good agreement with predictions of rapid distortion theory in the region of its validity is obtained. Also, the normal Reynolds stress proflles are found to be in qualitative agreement with available experimental data.