Parametric Study on Ridges Inducing Secondary Motions in Turbulent Channel Flow

A DNS parametric study of streamwise?aligned rectangular ridges is carried out in a fully developed turbulent channel flow with constant rate at $Reb = 18000$. The simulations were systematically varying the ridge height h, width w and structural wavelength $S$. generate strong large?scale secondary motion, which measured terms integral swirl strength. Of presented cases, configuration height$ h 0.1 \delta$, $S/w 4$, $ S 1 \delta$ produces strongest $4.5\%$ $U_b$. topology discussed as result dimensions.