A Numerical Study of Heat Transfer and Fluid Flow Over an In-line Tube Bank

Heat transfer and fluid flow over an in-line tube bank using computational fluid dynamic prediction is presented in this study. The study considers steady laminar two-dimensional incompressible flow over in-line tube bundles used in heat exchanger applications. The effect of various independent parameters, such as Reynolds number (Re), length aspect ratio (L/D = 2.5, 2, 1.5, 1.0, 0.5, and 0.0), and fluid flow on the pressure drop and heat transfer, is studied. A computer code (CFD-Fluent) is generally used to predict the heat transfer and pressure drop characteristics of flows around or through rigid complex geometry, namely, domains whose boundaries do not coincide with coordinate lines of a Cartesian or any simple coordinate system. A comparison is made between the present computational fluid dynamic predictions and reference measurements [Iwaki, C., Cheong, K. H., Monji, H., and Matsui, G. 2004. PIV measurement of vertical cross flow structure over tube bundles. Experiments in Fluids 37:350–363] for the velocity vector as fluid flow over a cylinder in cross flow for the selected values of Reynolds numbers Re_D. Therefore, the comparison is made between the present computational fluid dynamic results and Martin empirical correlation of in-line circular tube for the variation of Nu with Re_D. A reasonable agreement is observed. The results of the present study provide sufficient confidence in using empirical correlations to undertake initial sizing of tube bank heat exchanger design, with thermo-fluid performance subsequently predicted by computational fluid dynamic analysis for specific requirements applications.