Propulsion of Photovoltaic Cruiser-Feeder Airships Dimensioning by Constructal Design for Efficiency Method

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. While the traditional constructal method performs an optimization with a down-to-top approach, it produces an optimization process in two stages: the first one defines the optimal characteristics of the system understood as a unitary system to achieve the desired performances; the second analyzes the subsystems, examining those most disadvantaged, in order to optimize its performance for the desired goal. It has been deeply tested on a traditional shaped airship allowing verifying that a changing volume airship has globally better energetic performances than a fixed volume one. This paper performs a preliminary analysis of the method for the design of a cruiser/feeder multibody airship such as the one, which is going to be designed inside the MAAT project. The model presented defines the guidelines for the optimization of the system considering the magnitudes involved in flight physics to achieve the goal of energetic self-sufficiency.