EFFECT OF DIFFERENT WALL FUNCTIONS ON THE PREDICTION OF FLOW AND HEAT TRANSFER CHARACTERISTICS IN PLATE FIN AND TUBE HEAT EXCHANGERS

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In the present study, effects of wall functions available in the Fluent software on the fluid
flow and heat transfer characteristics of a plate fin and tube heat exchanger are investigated in the range
of 6000Re500 ≤≤ for a non-dimensional fin spacing of 233.0=sF and the results are compared with
experimental data. As it is well-known, wall functions are used to bridge the viscosity-affected region
between the wall and the fully turbulent region in the flow domain. Both Standard k-ε and RNG k-ε
turbulence models are employed in order to predict the flow and heat transfer characteristics inside the
flow passage of the plate fin and tube heat exchanger comprised of four-row of staggered tube layout
with wavy fin configuration. The test heat exchanger model is selected from the experimental work
exists in the literature and the best wall function that has close agreement with the experimental data is
chosen as Enhanced Wall Treatment.