Experimental and Numerical Investigations on Louvered Fin-and-Tube Heat Exchanger With Variable Geometrical Parameters

Abstract

The effects of geometrical arrangement on the heat transfer and pressure drop characteristics in compact louvered fin-and-tube heat exchangers were studied experimentally and numerically along with ε−NTU method. Different geometrical parameters including louver angle, louver pitch, louver number, the nonlouvered inlet and exit fin length, and redirection of fluid flow are considered to determine their effects on the flow field. The study is performed for different louver angles varying from θL=12 to 60 deg, and optimal heat transfer rate is obtained at louver angle of θL=28deg. Also, it is found that increasing the louver number, NL, on the fin surface enhances the heat transfer performance. It is shown that the average Nusselt number is increased as the louver pitch is decreased and its optimum value is obtained at Lp=0.9 mm. However, comparing to the effect of louver number, the louver pitch has a small effect on the performance of the heat exchanger. Additionally, the optimum values of nonlouvered inlet and exit fin length and redirection length of fin are obtained with different flow conditions.