Numerical Investigation of the Air-Side Thermal Hydraulic Performance of a Louvered-Fin and Flat-Tube Heat Exchanger at Low Reynolds Numbers

In this study, the air-side heat transfer and fluid flow characteristics of a louvered-fin and flat-tube type heat exchanger used in the household refrigerators were investigated numerically. Louver angles of 20°, 24°, 28°, and 32° and fin pitches of 1.50, 2.00, and 2.50 mm were tested. To represent domestic refrigeration systems, the simulations were conducted for low Reynolds numbers, between 223 and 573. The results were evaluated using the volume goodness factor for the air side. The best performance was obtained with louver angle of 20° and fin pitch of 1.50 mm at Reynolds number of 229 over the investigated cases. It was demonstrated that the Colburn j-factor, friction factor, Stanton number, and volume goodness factor did not change linearly with respect to the parameters considered.