Heat and mass transfer between a rough wall and turbulent fluid flow at high Reynolds and Péclet numbers

摘要: General dimensional and similarity arguments are applied to derive a heat mass transfer law for fully turbulent flow along rough wall. The derivation is quite analogous Millikan's (1939) of skin-friction smooth-and rough-wall flows the smooth-wall by Fortier (1968a, b) Kader & Yaglom (1970, 1972).The equations derived or coefficient (Stanton number) Ch Nusselt number Nu include constant term β logarithmic equation mean temperature concentration diffusing substance. This function Prandtl number, dimensionless height wall protrusions parameters describing shapes spatial distribution protrusions. general form roughly estimated simplified analysis eddy-diffusivity behaviour in proximity (in gaps between protrusions). Approximate values numerical coefficients found from measurements velocity (or concentration) above walls. agrees satisfactorily with all available experimental data. It noted that results obtained indicate roughness affects two ways: it produces additional disturbances augmenting simultaneously retards fluid second effect leads some cases deterioration as compared case smooth at same Reynolds numbers.