Heat transfer and friction factor characteristic investigation of roughened solar air heater using arc-shaped wire rib roughness
Harish Kumar Ghritlahre
Abstract
In the present study, heat transfer and friction factor of arc-shaped roughened solar air heater with apex upstream and apex downstream flow have been examined through experiments. To achieve this aim, experiments were conducted with mass flow rate from 0.007 to 0.022 kg/s, and variations of mass flow rate on heat transfer and friction factor were examined. The arc-shaped roughness with relative roughness pitch, relative roughness height, rib roughness and arc angle was 10°, 0.0395°, 2.5° and 60°, respectively. The heat transfer of apex upstream flow, averagely enhanced by 1.42 times, performs better than that of apex downstream flow. In addition to this, the thermohydraulic performance has been determined for the given range of flow parameters and roughness arrangements. The above result reveals that apex upstream flow is more efficient than the apex downstream flow.