Numerical investigation of 3D turbulent forced convective heat transfer and friction characteristics of a square duct

Abstract

Numerical investigations are carried out in a three dimensional square duct with wedge shaped rib and groove turbulators on its top and bottom wall to examine the effect of geometric parameters on turbulent forced convective heat transfer and friction characteristics. The study is perofrmed for geometric parameters for orientation of turbulators, groove height, rib gap, turbulator length and pitchat Reynolds number ranging from 10000 to 30000. The constant heat flux boundary condition is specified at the entire surfaces of the duct. The smooth duct is validated with the correlations established by Dittus Boelter, Gnielinski, Blasius and Petukhov. For this numerical assessment, k-? turbulence model with enhanced wall treatment is used. The thermal enhancement is reported in terms of Nusselt number (Nu), Darcy friction factor (f) and thermal enhancement factor (TEF). Both the heat transfer and friction loss are found sensitive to the changes in the geometric parameters.