An experimental investigation on upward solar air heater with impinging air jets

This study presents and discuss the results of an experimental investigation conducted to understand and quantify the impact of air mass flow rate(m) over the heat transfer attributes of an upward solar air heater (SAHRR) utilizing impinging air jets. Experimental investigation was carried out for various mass flow rates ranging from 0.008 to 0.024 kg/s for various impinging air jet diameters (4, 6 and 8 mm). The thermal performance was evaluated based on the average value of Nusselt number, first law thermal efficiency, thermohydraulic efficiency and exergy efficiency. The lowest and the highest first law efficiency for an upward SAHRR employing 6 mm diameter jet is between 44 % and 88 %, respectively, when the solar radiation maintained is 1000 W/m2. Moreover, the final outcomes are compared with the base model (SAHRR without jet impingement) in order to highlight the positive impact of jet impingement on the performance of SAHRR.