Effect of longitudinal pitch on convective heat transfer in crossflow over in-line tube banks

An analytical study using a CFD (Computational Fluid Dynamics) code has been performed to investigate the effect of the longitudinal pitch on the single-phase heat transfer characteristics in crossflow over in-line tube banks. A simplified geometry with periodic and symmetric boundary conditions is employed for the analysis. A sensitivity analysis using various two-equation turbulence models has been conducted to examine the impact of the turbulence model on the heat transfer characteristics and to determine a turbulence model that can describe the physical phenomena of interest appropriately. The result indicates that the heat transfer coefficient might be reduced by 37.1% from the prediction by a well-known correlation by Zukauskas (Adv. Heat Trans., 2007, 8, 93) as the longitudinal pitch decreases. By analyzing the result, it is found that the heat transfer degradation can be estimated by using an empirical correction factor and the Zukauskas' correlation can predict existing experimental data when the correlation is combined with the empirical correction factor developed in this study. (C) 2013 Elsevier Ltd. All rights reserved.