Machines. Technologies. Materials.
Vol. 19 (2025), Issue 8, pg(s) 276-279

MACHINES

Air-Side Pressure Drop and Heat Transfer Analysis in Slotted Fin and Tube Heat Exchanger

  • 1 University of Rijeka, Faculty of Maritime Studies, Croatia
  • 2 University of Rijeka, Faculty of Engineering, Croatia

Abstract

Compact air-cooled fin-and-tube heat exchangers are widely used in various fields, including the automotive and computer industries, as well as in heating, air conditioning, refrigeration, and process applications. Due to the thermal characteristics of air, the majority of heat transfer resistance occurs on the air side of the heat exchanger. As a result, research in this area primarily concentrates on enhancing the air-side performance. Numerous studies in the literature explore different fin and tube configurations aimed at optimizing the design of these heat exchangers however, pressure drop is sometimes neglected. In this study, a numerical analysis was conducted to investigate air-side pressure drop and heat transfer in various configurations of slotted fin-and-tube heat exchangers whereby heat exchangers with different ellipticity ratios were considered. The numerical model of the three-dimensional, laminar, steady-state problem of air-side flow and heat exchange was done using the finite volume method. The convection-diffusion equations were discretized using the Power Law scheme, and the SIMPLE algorithm was employed to couple pressure and velocity. Simulations were carried out in ANSYS Fluent 18.2. The validation of the proposed model was tested by comparing the numerical results with experimental measurements available in the literature whereby no discrepancies greater than 5% were observed. Four different inlet air velocities ranging from 1 to 4 m/s, corresponding to Reynolds numbers between 558 and 2233 were considered. Both the inlet air temperature and the tube surface temperatures were kept constant at 293 K and 373 K, respectively. The results emphasize potential benefits of using elliptic instead of round tubes in slotted fin and tube heat exchangers to achieve lower air-side pressure drop without penalty of lower heat transfer.

Keywords

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