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Environmental and economic issues related to the aeronautic transport, with particular reference to the high-speed one are opening new perspectives to pulsejets and derived pulse detonation engines. Their importance relates to high thrust to weight ratio and low cost of manufacturing with very low energy efficiency. This papers presents a preliminary evaluation in the direction of a new family of pulsejets which can be coupled with both an air compression system which is currently in pre-patenting study and a more efficient and enduring valve systems with respect to today ones. This new pulsejet has bee specifically studied to reach three objectives: a better thermodynamic efficiency, a substantial reduction of vibrations by a multi-chamber cooled architecture, a much longer operative life by more affordable valves. Another objective of this research connects directly to the possibility of feeding the pulsejet with hydrogen.

The European project MAAT (Multi-body Advanced Airship for Transport) is producing the design of a transportation system for transport of people and goods, based on the cruiser feeder concept. This project defined novel airship concepts capable of handling safer than in the past hydrogen as a buoyant gas. In particular, it has explored novel variable shape airship concepts, which presents also intrinsic energetic advantages. It has recently conduced to the definition of an innovative design method based on the constructal principle, which applies to large transport vehicles and allows performing an effective energetic optimization and an effective optimization for the specific mission.

This paper presents a mathematical model of the vertical forces acting on an airship during vertical motion. The main effort is the definition of an airship model, which move only vertically by ballast, and buoyancy effects, with a much reduced energy consumption for take-off and landing operations. It has been considered a disc-shaped airship, which can operate using the open balloon airship architecture defined to operate safely with hydrogen. This architecture does not require internal ballonets, because of the connected increased fire dangers that they create even if vented. Several models of airship based on vertical forces have been presented in literature. They often consider only the US or International Standard Atmosphere models and they neglect effects of weather conditions. The latter are connected with the location and with the season.

This paper investigates the ancient idea of augmenting the thrust produced by a rotating fan by producing a thermal gradient by heating the outflow. Some of the pioneers of aeronautics have originally conceived this idea: the indirect jet (Bleriot Coanda Monoplane, 1910) and the “thermojet” (Caproni-Ciampini CC2, 1942). They were abandoned because of the better performances by traditional jets such as the ones developed in Germany and USA during 2nd World War. Antony Colozza (NASA), one of the modern fathers of high altitude airships, has recently proposed it again to be used on fuel cells powered airplanes and airships. Most fuel cells have a large thermal dispersion at high temperature (about 40%), but it could be possible to use it for heating the propulsive stream of high-speed air produced into ducted fan propulsive units.

This paper presents a model of energetic consumption and photovoltaic production for a large airship which acts as feeder connecting the ground with a large cruiser. The analysis of energy needs and productivity allows defining both an ideal sizing and operative mission profiles. The specialised mission of this airship is to ascent and descent. It includes also the connection with the airport buildings on the ground and with the cruiser at high altitude. Photovoltaic production has evaluated in terms of hydrogen and electric propulsion. They have estimated both and a calculation methodology has proposed. The evaluation has supported by CFD evaluations on aerodynamic behaviour of the system at various altitudes.

This paper presents the new Hydrogen Fire-safe Airship system that overcomes the limitations present in previous airships designs of that kind, when considering their functioning at advanced operative position. Hydrogen is considered to be more effective than helium because of its low-cost production by hydrolysis, which process is nicely driven only by the photovoltaic energy. This paper presents a novel architectural concept of the buoyant balloon designed to increase the fire related safety, when applying hydrogen as the buoyant gas. The proposed buoyant volume is designed as a multi-balloon structure with a naturally ventilated shape, to ensure that hydrogen cannot reach the dangerous concentration level in the central airship balloon. This concept is expected to be the start of a novel hydrogen airship type, to be much safer than preceding ones.