An investigation of influence factor including different tube bundles on inclined elliptical fin-tube heat exchanger

Abstract A three-dimensional (3D) computational fluid dynamics (CFD) study is conducted to investigate the influence of tube ellipticity ratio e, tube rotation angle θ and fin spacing H on heat transfer capability. The tube ellipticity ratios range from 0.4 to 1.0 with increments of 0.1. The Reynolds number in the fluid domain varies from 1300 to 2100. The tube rotation angle ranges between 0° and 90°. The performance of heat exchanger is evaluated by non-dimensional parameters Colburn factor j, friction factor f, and Area goodness factor j/f. It can be concluded from this study that when Reynolds number and elliptical ratio are the same, a maximum of Colburn factor j occurs as θ increases, while the friction factor f keeps increasing. Furthermore, the maximum value decreases as the ellipticity ratio increases. The area goodness factor decreases sharply when θ > 45° for heat exchangers with different ellipticity ratios. The study also suggests that the inclined elliptical fin-tube heat exchanger with the tube ellipticity ratio e = 0.6 and rotation angle θ = 30° has the best heat exchange performance and airflow characteristics.