Performance Analysis of Solar Air Heater with Circular Finned Absorber Plate

In this report, we perform a numerical analysis of a three-dimensional solar air heater (SAH) having a finned absorber plate. The number of fins of circular cross-section (h = 5 mm to h = 25 mm) has been varied from 10 to 25. Finite volume method is adopted to solve the problem numerically. Fluid flow considered in the turbulence regime where Reynolds varies from 4000 to 16,000. Continuity, momentum, and energy equations with k-ε RNG turbulence model are solved to obtain the velocity and temperature field. Brief results of heat transfer are explained with the aid of graphical plots and contours. A uniform heat flux of 1000 W/m2 is applied over the absorber plate. It is observed that the performance of the solar air heater mainly depends on Reynolds number, fin height, and relative coarseness of fins. It is found that the average absorber surface temperature at ten fins is 339.92 K and at 335.5944 K at 15 fins, which is the least among all cases. When the number of fins increases beyond 15, the absorber temperature starts rising and becomes 337.737 K at 25 fins. Thus, 15 fins on the absorber plate are the optimum configuration for maximum heat transfer.