Abstract

This paper suggests a method for finding the optimal louver angle of a fin heat exchanger by use of a simplified conjugate-gradient method (SCGM) and a three-dimensional computational fluid dynamics model. The search for optimum louver angles ranging from θ= 15^o to 45^o for suitable louver pitches and fluid input velocity are carried out for Reynolds number Re_H (based on the fin spacing 1.5 mm and the frontal velocity 1 to 5 m/s) ranging from 100 to 500. The area reduction of using louver surface relative to the plain surface is the objective function to be maximized. The model calculates optimum performance of the heat-exchanger by means of finding the fin angle which would give the biggest reduction in area of the louvered surfaces relative to plain fin surfaces required to give equivalent performance. The numerical optimizer adjusts the angle of the louvered fin toward the maximization of the performance of the heat exchanger. Additionally, the correlations of the optimal louver angle as function of Reynolds number Re_H are obtained.

Key words: Heat transfer, louvered fin, optimization, simplified conjugate-gradient method.