Growth of Turbulent Boundary Layer with Varying Inlet Length Scales

Abstract

This study aims to generate a fully developed turbulent boundary layer in the channel domain using LES (Large Eddy Simulation), suitable inflow conditions along with statistically reliable turbulent characteristics are required. This study clarifies the effect of the integral length scale from the existing data on the generation of turbulent boundary layers. In order to justify the work, an artificially created boundary layer is imposed on the inlet section, which gradually evolves into a fully developed turbulent boundary layer flow inside the numerical domain. In this study, the synthetic inflow method, which is based on an exponential correlation function, is used by imposing the spatial and temporal correlation between two different points on the inlet section. In addition, we conducted parametric length scale studies on the inlet section and compare our results with existing data. The results indicated that the cases of larger length scale in the span-wise direction were not only effective in achieving the target shape of a fully developed turbulent boundary layer, but also developed it faster than the smaller-length scales.