Influence of twisted tape fins on heat transfer and friction factor characteristics for impinging jet solar air heater

Abstract

In this work, an experimental study was carried out to investigate the enhancement of heat transfer and friction factor characteristics of an impinging jet solar air heater integrated with twisted tape fins. During the analysis, the Reynolds number fin design parameters namely twist ratio (Y), and pitch ratio (p_y) are varied from 3500 –13500, 5.5–9.5, and 0.1–0.3, respectively. During the experimentation, the constant heat flux of 1000 W/m² was maintained on the absorber plate. From the results, it was observed that the heat transfer rate increases while increasing the twist ratio up to 7.5 and further increase in twist ratio diminishes the performance. It was also concluded that the rise in pitch ratio (p_y) deteriorates the rate of heat transfer. The present work enhances the heat transfer and friction factor by the maximum of 1.9 and 1.81 times as compared with the conventional jet impingement solar air heater at identical operating conditions.