Experimental investigation on heat transfer augmentation of solar air heater using shot blasted V-corrugated absorber plate

In the present work, an experimental investigation on surface modified solar air heater was carried out to study the rate of heat transfer and friction characteristics under the laminar flow conditions. The inner surface of the rectangular duct with V-corrugated absorber plate was roughened by shot blasting process through pressurized shot blasting mechanism. The parameters influencing the Nusselt number and friction factor were discussed and the results obtained are compared between the modified shot blasted absorber plate and conventional absorber plate under similar flow conditions. The main inference from the experimental result is that the Nusselt number for V-corrugated shot blasted absorber plate is higher than the conventional absorber plate and the friction factor is slightly higher for V-corrugated shot blasted absorber plate as compared to conventional absorber plate. The results further showed that during the initial duration of the experiments, the effect of Reynolds number on thermal performance factor is mainly governed by the friction factor and later the thermal performance factor tends to decrease with the increase of Reynolds number.