Thermal performance analysis of a high-altitude solar-powered hybrid airship

The increasing application of hybrid airships which have been recently proposed as high altitude platforms, makes it necessary for research into the thermal performance of such airships that possess a photovoltaic module array(PVMA). In this study, a simplified thermal model of a high-altitude hybrid airship with a PVMA, was proposed that included direct solar, infrared, reflected, and scattered radiation and convective heat transfer. Based on computational fluid dynamics(CFD), a simulation methodology, using a user defined function(UDF) program, was introduced to investigate the PVMA's thermal effects on the hybrid airship. A ground experiment was also performed to validate this numerical method's effectiveness. Further simulations and discussion of temperature and velocity distributions of the hybrid airship's internal helium were conducted. The results showed that the PVMA atop the hull had large effects on the hybrid airship's thermal performance. The temperature distribution of the envelope varied greatly during the day and night because of the PVMA's influence as well as the internal helium flow. In addition, forced convection had little influence on the PVMA's output performance, which was analyzed in detail.