Solar car aerodynamic design for optimal cooling and high efficiency

摘要

Forced convection cooling of photovoltaic modules mounted on the surface of moving solar car is considered. It is shown that the shape of the car should be optimized not only to reduce aerodynamic drag but also to enhance heat removal and to increase power generated by photovoltaic modules. The module is modeled by local energy balance equation providing boundary condition for equations of aerodynamics. Experimental data on surface temperature are obtained for a flat module and compared to engineering approximate relation and numerical simulations. Simplified approach is proposed based on solving energy equation separately from equations of momentum and continuity. Unlike analytical approximations, it provides accurate results if power generation depends on surface temperature. The results of numerical simulations for two different shapes of the solar car demonstrate that photovoltaic modules placed in flow separation regions should be treated as separate blocks, otherwise they can limit the performance of the whole system. Linear analysis of the power loss of photovoltaic array due to partial overheating or shading is also performed.