Abstract: In this paper, a multi-layer node model, which is based on the two-node model, is proposed for thermal analysis of aerostats. The thermal performance simulation of a National Aeronautics and Space Administration (NASA) ultra long duration balloon suggests that the multi-layer node model can provide the distribution of different envelope parts and the development of helium temperature tendency with time. It is found that the diurnal temperature variation between top envelop and bottom envelop is smaller than that of stratospheric airships. It is also concluded that a low helium temperature difference can be reached at a high latitude position and a low helium temperature can be reached at a low altitude. The conclusions are valuable for superheat control of stratospheric aerostats.

Key words: stratospheric aerostat, thermal characteristics, multi-layer node model, station-keeping