Influence of Surface Anisotropy on Turbulent Flow Over Irregular Roughness
Angela Busse, Thomas O Jelly
Flow, Turbulence and Combustion | Springer Verlag | Published : 2020
The influence of surface anisotropy upon the near-wall region of a rough-wall turbulent channel flow is investigated using direct numerical simulation (DNS). A set of nine irregular rough surfaces with fixed mean peak-to-valley height, near-Gaussian height distributions and specified streamwise and spanwise correlation lengths were synthesised using a surface generation algorithm. By defining the surface anisotropy ratio (SAR) as the ratio of the streamwise and spanwise correlation lengths of the surface, we demonstrate that surfaces with a strong spanwise anisotropy (SAR 1) equivalent. Furthermore, we find that the relationship between the roughness function ΔU+ and the SAR parameter appro..View full abstract
Awarded by United Kingdom Engineering and Physical Sciences Research Council (EPSRC)
This study was funded by the United Kingdom Engineering and Physical Sciences Research Council (EPSRC) (grant numbers EP/P004687/1, EP/P009875/1 and EP/L000261/1).