Numerical investigation of the air-side performance of louver fin-and-tube radiators having rectangular, tapered and airfoil section configuration

Abstract

As the most widely used type in automobile industry, louver fin-and-tube radiator plays an important role in maintaining the stable operation of automobile. In order to further improve the heat transfer and flow performance on the basis of the original rectangular louver fin, a new type of airfoil louver fin was designed in this paper, and the air-side performance of airfoil, tapered and rectangular louver fin under different geometric parameters was numerically simulated by computational fluid dynamics (CFD). A total of fourteen samples are made and simulated with the corresponding louver angle (θ) being 23°, 26° and 29° and the louver length (Fl) are 1.2 mm, 1.4 mm and 1.6 mm respectively. The results reveal that the airfoil louver fin had the highest Nusselt number (Nu) and minimum friction factor (f) for all the studied cases. The Nu for the airfoil louver fin can be increased up to 4.9% over the rectangular louver fin and the corresponding pressure difference decreased up to 16.6%. However, because the heat transfer area of airfoil and tapered louver fin is slightly lower than that of rectangular louver fin, the heat transfer of airfoil and tapered louver fin is slightly lower than that of rectangular louver fin at θ=26° and 29° and low air inlet velocity. When the air inlet velocity is further increased, the heat transfer of airfoil and tapered louver fin is slightly higher than that of rectangular louver fin. Likewise, the heat transfer of airfoil and tapered louver fin is also slightly lower than that of rectangular louver fin for Fl=1.4mm and 1.6 mm. The heat transfer of airfoil louver fin is the highest at θ=23° and Fl=1.2mm.