In the present work, Aluminium wire of 20 mm diameter in the form of continuous arc type geometry has been used as artificial roughness underside the absorber plate. Two set ups were used: first set up was rough solar air heater with roughened absorber plate (RH) and other was solar air heater with smooth absorber plate (SH). It was found that when the solar radiation starts decreasing, the outlet air temperature of RH was still higher than ambient and inlet temperature because of the thermal storage system. Outlet air temperature of SH was maximum (75°C) at 1: 00 pm and minimum (38°C) at 7: 00 pm. Outlet air temperature of RH was maximum (67°C) at 1: 00 pm and minimum (44°C) at 7: 00 pm. Up to about 4: 00 pm, the outlet air temperature of SH was recorded higher as compared to RH. Afterwards, the outlet air temperature of RH was recorded higher than that of SH. After 4: 00 pm, the average elevated outlet air temperature of RH was found to be 4.7°C higher than that of SH. These data indicated the smooth functioning of RH as compared to SH.
artificial roughness, solar air heater, thermal storage
