A Validated Simulation of Wind Flow Around a Parabolic Dish

The thermal performance of solar parabolic dish systems is greatly influenced by the wind around the system. To achieve higher operating temperatures, larger dish structures are used to increase the concentration ratio, however, the air flow around the structure affects the convective heat loss from the receiver. Previous studies investigating the effect of heat losses from the cavity receiver have treated it as a separate entity decoupled from the reflector. However, the interaction between wind and the dish structure can affect the local air speed at the cavity inlet and thus the heat loss as well. In order to investigate the flow behavior, a three dimensional computational fluid dynamics (CFD) model was used to predict the steady-state flow around the parabolic solar dish at different operating conditions. The CFD model was subsequently validated with experimental data collected from wind tunnel testing for the dish at different pitch angles and with varying wind speeds. The results support the assertion that the flow characteristics near the cavity receiver aperture depend strongly on the orientation of the dish structure and this needs to be taken into account when analyzing the performance of parabolic dish systems