Numerical Simulation of Effect of Topology on the Airflow Characteristics inside an Indirect Solar Dryer

The present work is part of the optimization of indirect solar dryers. The main objective is to highlight the influence of topological forms of dryers on air settings. For this, we have studied the behavior of air in the collector for four inclinations angles (0°, 30°, 40° and 60°), three values of the height of the drying chamber (1, 1.20 and 1.40 m) and three values of the height of the chimney (0.3, 0.8, and 1.5 m). The Navier-Stokes equations were numerically solved using the finite volume method through the Easy CFD_G package code in its V.4.1.0 version. The numerical simulation was used to define for each load configuration studied, the temperature profile, velocity and pressure. The results show that for the solar collector, 30° is the optimum angle of inclination. This angle provides a better distribution of the velocity vector field. For this angle, the height of the drying chamber allowing a better distribution of velocity and temperature gradient is 1.40 m. The maximum chimney height is 1.5 m. These parameters are used to define an optimal configuration of the indirect solar dryer in which the air temperature varies between 56 and 64°C and drying air velocity between 0.5 and 0.9 m/s.