Conjugate turbulent forced convection in a channel with an array of ribs

Abstract

Purpose

Performance of various k‐ε models on turbulent forced convection in a channel with periodic ribs is assessed.

Design/methodology/approach

The influence of the Yap correction and the non‐linear stress‐strain relation on the predictions of mean‐flow, turbulence quantities and local heat transfer rate is examined. The effect of thermal boundary conditions on the heat transfer predictions is investigated by employing both the prescribed heat flux approach and the conjugate heat transfer approach.

Findings

It was found that the inclusion of the Yap correction in the ε‐equation significantly improves the predictions of mean velocity and wall heat transfer for both high‐Reynolds number and low‐Reynolds number k‐ε models in the present ribbed channel flow with massive flow separation. The employment of the non‐linear stress‐strain relation only marginally improves the predictions of turbulence quantities: the turbulence anisotropy is reproduced although the level of turbulence intensity is still too low. In general, the conjugate heat transfer approach predicts better average Nusselt number than the prescribed heat flux approach. However, both approaches under‐predict the experimental value by about 28‐33 percent when the low‐Reynolds number k‐ε model of Lien and Leschziner (1999) with the Yap term is adopted.

Originality/value

Thorough numerical treatments of the thermal boundary conditions at the solid‐liquid interface, and detailed periodic condition in the periodic regime, were given in the paper to benefit researchers interested in solving similar problems.

Citation

Hsieh, K.J. and Lien, F.S. (2005), "Conjugate turbulent forced convection in a channel with an array of ribs", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 15 No. 5, pp. 462-482. https://doi.org/10.1108/09615530510593648