Aerodynamic characteristics study and possible improvements of MAAT feeder airships

This paper is dedicated to the study and improvement of the aerodynamic properties of the feeder airship in the context of MAAT project. FP7 MAAT project is based on the concept of two different types of airships (the cruiser and the feeder) working together as a transportation system. The current feeder concept includes unconventional shape changing envelope. Two problems are considered in this paper. The first problem is to find a condition of the effective vertical ascent for the feeder (from the ground to the altitude of the cruiser). A series of CFD simulations were carried out for the top flow for a range of altitudes from 0 to 16 km and velocities between 2 and 10 m/s. The results confirm the appearance of some negative effects, including high drag during the vertical ascent, especially, at low altitudes. The second problem is to study and reduce the side wind effects on the ascending feeder airship. Another series of CFD simulations was conducted for the side flow at the same altitudes as in the first problem and for the velocities between 10 and 50 m/s. The results show the occurrence of the effect of downforce wing (negative lift) on the altitudes of 1014 km. The authors have provide suggestions for the shape variations in order to reduce high drag during vertical ascent and negative lift effect caused by side wind.