Simulation of mixed-mode solar dryer with vertical air distribution channel

Final quality of product in drying process significantly depends on the flow behavior of drying air. The main drawback of conventional solar dryers is the non-uniformity of air flow inside the drying chamber. The flow behavior of drying air in transient state have been analyzed using Computational Fluid Dynamics (CFD) method. The Do radiation, species transport and k-omega SST models were used. The comparison of the numerical results of temperature distribution with the experiment revealed a reasonable agreement. Between top and bottom trays 0.015 m/s velocity and 2 % relative humidity variations were observed. The dryer provided the required air temperature for solar drying. The results revealed that using vertical air distribution channel can improve the drying process by increasing homogeneity of drying air distribution. Modification of natural conviction mixed type dryer is possible by combining CFD with experimental investigation.