Numerical Prediction of Turbulent Flow and Heat Transfer Within Ducts of Cross-Shaped Cross Section

Calculations were carried out for fully developed turbulent flows within ducts of cross-shaped cross section using the numerical method based on the pressure correction method developed by Patankar and Spalding. The Reynolds stress driven secondary flows were simulated successfully by Launder and Ying’s algebraic stress model coupled to the k–ε turbulence model. A parametric study was made on the friction and heat transfer characteristics in terms of the parameter α associated with the decrease in the cross-sectional area, namely, α = 0 for a square duct, and α → 1 for infinite parallel plates. Through performance evaluations, it has been found that both the Reynolds analogy factor and the heat transfer coefficient under equal pumping power decrease slightly, while the heat transfer coefficient obtained with equal mass flow rate increases appreciably with α, suggesting effective turbulent heat transfer within ducts of cross-shaped cross section.