Three Dimensional CFD Simulation of Two -Row Plain Fin & Tube and Heat Exchanger

Three-dimensional CFD simulations are carried out to investigate heat transfer and fluid flow characteristics of a two-row plain fin-and-tube heat exchanger using ANSYS FLUENT. Heat transfer and pressure drop characteristics of the heat exchanger are investigated for Reynolds numbers ranging from 330 to 7200. Model geometry is created, meshed, calculated, and post-processed using ANSYS Workbench. Fluid flow and heat transfer are simulated and results compared using both laminar and turbulent flow models (k-epsilon, and SST k-omega), with steady-state solvers to calculate pressure drop, flow, and temperature fields. Model validation is carried out by comparing the simulated case friction factor f and Colburn j factor with experimental results from the literature. For friction factor determination, little difference is found between the flow models simulating laminar flow, while in transitional flow, the laminar flow model produced the most accurate results and the k-omega SST turbulence model was more accurate in turbulent flow regimes. The results of simulations for heat transfer in laminar flow using the laminar flow model are found to be in good agreement with the experimental results, while heat transfer in transitional flow is best represented with the SST k-omega turbulence model, and heat transfer in turbulent flow is more accurately simulated with the k-epsilon turbulence model. Reasonable agreement is found between the simulations and experimental data, and the ANSYS FLUENT software has been sufficient for simulating the flow fields in tube-fin heat exchangers.