Simulation of Forced Convection Heat Transfer in a Solar Air Heater with Different Aspect Ratios

In this paper, the results of a numerical study on 2-D laminar forced convection in a flat-plate solar air heater are presented. This study aims to establish the optimal performance parameters for the maximum efficiency during the collection of solar energy. Simulations have been performed for two air mass flow rates of 0.01 and 0.02 kg/s, two aspect ratios of 1 and 2 and two uniform heat fluxes of 500 and 1000 W/m2. These cases include a state in which air flows through a space between absorber plate and glass cover. The absorber plate and glass cover temperatures have been obtained, pressure and temperature contours have been studied and efficiency of the air heater has been recognized. The results have shown that for a constant mass flow rate, with increasing heat flux the efficiency of collector increases. Also for the constant heat flux, when themass flow rate increases, the efficiency increase either. On the other hand, for a constant heat flux and mass flow rate, if the inlet air temperature is increased the efficiency decreases. Seemingly with increasing the aspect ratio, which increases the area of the absorber plate, the efficiency decreases.

Simulation of Forced Convection Heat Transfer in a Solar Air Heater with Different Aspect Ratios Keywords:

Solar air heater , Forced convection , Aspect ratio , Collector efficiency