Reynolds and dispersive shear stress contributions above highly skewed roughness
Thomas O Jelly, Angela Busse
JOURNAL OF FLUID MECHANICS | CAMBRIDGE UNIV PRESS | Published : 2018
The roughness functions induced by irregular peak- and/or pit-dominated surfaces in a fully developed turbulent channel flow are studied by direct numerical simulation. A surface generation algorithm is used to synthesise an irregular Gaussian height map with periodic boundaries. The Gaussian height map is decomposed into 'pits-only' and 'peaks-only' components, which produces two additional surfaces with similar statistical properties, with the exception of skewness, which are equal and opposite . While the peaks-only surface yields a roughness function comparable to that of the Gaussian surface, the pits-only surface exhibits a far weaker roughness effect. Analysis of results is aided by d..View full abstract
Awarded by EPSRC
This work was funded by EPSRC grant EP/P004687/1. Compute time on the ARCHER facility (http://www.archer.ac.uk) via the UK Turbulence Consortium (EPSRC grant EP/L000261/1) and ARCHIE-WeSt High Performance Computer (www.archie-west.ac.uk) (EPSRC grant EP/K000586/1) are gratefully acknowledged. The roughness height maps and the velocity statistics are available in. csv format at http://dx.doi.org/10.5525/gla.researchdata.640.