Abstract: In this article, some aerodynamics problems and the importance for both low and high altitude airships while launching, recovering, hovering or tethered are analyzed. Development and achievement of airship dynamics research are introduced, and some problems which need further study are also pointed out. The aerodynamics problems of low altitude airships consist of the flow separation and drag reduction for blunt hulls, nonlinear interactions of non-flat components, fluid-structure interaction due to flexible envelope or tethering, and sensitivity to environment due to low speed, etc. Many researchers have been working on these problems. High altitude airships also involve some extra aerodynamics problems including coupling with thermal and buoyance, shape deforming between day and night, response to turbulence during launch or recovery, shear of wind, etc, the studies of which are still at the starting stage. In addition, we preliminarily and numerically simulate the ambient flow field around airships, considering the influences of the ground and atmospheric boundary layer, polygonal cross-sectioned hulls, interaction between the jet flow from ballonets and the incoming flow, which are relatively less studied.

Key words: low and high altitude airship, aerodynamics, fluid-structure interaction, launch and recovery