Mathematical Modeling and Aerothermal Simulation of a Small-scale Solar Updraft Power Generator

In this study, an integrated mathematical model is developed to simulate the updraft velocity and temperature of airflow inside a small-scale solar updraft power generator. The model is derived for axisymmetric and inviscid flow conditions where the kinetic energy of the airflow is extracted by using a wind turbine generator. A numerical model based on energy balances at the component level of a small-scale solar updraft power generator is proposed and validated with existing experimental data. The applicability of heat transfer correlations is assessed through computed Rayleigh and Reynolds numbers. All correlations maintain a fast convergence and remain in their range of validity throughout the iteration. Simulation results further reveal that heat losses at the edge of the collector have significant effects and play an important role in both updraft velocity and temperature of airflow. About 3 W/m² of heat loss to the edge of the collector was obtained from simulation result. The comparison between simulation and experimental data demonstrates that both results are in good agreement.