Mauro Madonia

Effects of Altitude on Photovoltaic Production of Hydrogen

This paper compares hydrogen production by photovoltaic powered electrolysis of water at sea level and at low stratospheric altitudes up to 21 km. All the hydrogen production process has been considered from catchable solar radiation to storage technologies. The evaluation has been performed for 1 m2 of flat horizontal plane. It has been considered the electric energy amount produced considering variations in equilibrium temperature and in solar. Hydrogen production through electrolysis has been evaluated too. Two different methods of hydrogen storage have been evaluated: high pressure compression up to 20 MPa and liquefaction process. The energetic cost of both production processes has been evaluated. The comparison is presented in terms of effective energy deliverable to final users considered in terms of HHV. This evaluation considers also, in the case of liquefaction process the energy which can be recovered by the rigasification process.Copyright

Acheon Project: A Novel Vectoring Jet Concept

This paper presents a general overview of the ACHEON Project (EU FP7 Level 0 - Transport including Aeronautic).This project presents a novel dynamically controllable Coanda jet using two fluid streams to produce the angular deflection of the jet as a function of their momentum. A control system with electrostatic plasma is used to produce an effective and more precise control of the system.This paper presents the general guidelines of the project which is going to start and presents expected results.Copyright

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.

CFD Analysis and Optimization of a Variable Shape Airship

This paper presents the CFD simulation of a novel airship concept that can change the external volume and shape as a function of altitude. This novel concept of airship defined in the MAAT project (the project of a stratospheric cruiser/feeder airship) is necessary for two fundamental reasons: minimizing risks due to the use of hydrogen as buoyant gas and reducing the power necessity for propulsion. The unconventional feeder system has been analyzed from ground level up to 16,000 m, which the desired operative altitude of the cruiser.© 2012 ASME

Preliminary implementation study of ACHEON thrust and vector electrical propulsion on a STOL light utility aircraft

One of the best airplanes ever realized by the European Aircraft industry was the Dornier Do 28D Skyservant, an extraordinary STOL light utility aircraft with the capability to carry up to 13 passengers. It has been a simple and rugged aircraft capable also of operating under arduous conditions and very easy and simple maintenance. The architecture of this airplane, which has operated actively for more than 20 years, is very interesting analyzing the implementation of a new propulsion system because of the unusual incorporation of two engines, as well as the two main landing gear shock struts of the faired main landing gear attached to short pylons on either side of the forward fuselage. This unconventional design allows an easy implementation of different propulsion units, such as the history of different experimental versions allowed. This paper presents the preliminary definition of an increased performance cogeneration system for optimizing the energy efficiency and maximizing the thrust of ducted fan propeller. It then produces an effective design of the ACHEON nozzle for such an aircraft, the definition of the optimal positioning for stability and efficiency. In conclusion, it analyses the expected performances of the resulting aircraft architecture. Outstanding results allows verifying an effective possibility of implementing the ACHEON Coanda effect thrust and vector propulsion system on real aircraft.

Energetic Efficiency Evaluation of a Town by Aerial Thermography

This paper presents a preliminary study to evaluate energy dissipation of a town by the use of aerial thermography. The model has been realized for the town of Reggio Emilia taking into account the different optical and physical parameters which influences the infrared measurement. Altitude and operational speed are analysed on an optical point of view to minimize distortions of images and produce a sufficient resolution. By this analysis a parametric model has been defined.Copyright

HYDROGEN AIRSHIPS: A NECESSARY RETURN BECAUSE OF HIGH COSTS OF HELIUM

Many airship projects have been presented during last years. Most of them are slowed in their realization because of very high costs of Helium. This paper presents an economic and energetic comparison between Helium filled airships and Hydrogen filled ones under the hypothesis of buying 20 MPa compressed Helium and local production of photovoltaic hydrogen by electrolysis. The economic evaluation comprises the costs of PV plant for hydrogen production and docking and distribution systems for both gasses. Analysis of uncertainty has been performed to evaluate economic parameters and payback time of the investments.

Constructal Design of an Entropic Wall With Circulating Water Inside

An entropic wall with circulating water inside could be a solution for acclimatizing a new building with high-energy efficiency and high levels of internal comfort. If circulating water is thermally stabilized by exchanging in the ground such has it happens in geothermal plants, a thermal shield could be realized keeping walls in comfort conditions and minimizing energy needs for further temperature regulations. This paper presents optimization guidelines of such a wall with the objective of maximizing the performances of the wall for reaching optimal internal wellness conditions. Optimization has been realized by a constructal law based method, which has been personalized by a step-by-step process and has been named constructal design for efficiency (CDE). The optimization of the system has been produced at different levels. It starts from a preliminary analysis at system levels, which allow defining the best objectives that could be reached. After this preliminary process, the system has been divided into modules, and the critical ones which have higher influence on the performances of the system have been evaluated. This analysis has been coupled also with an industrial analysis with the goal of defining an effective layout, which could be also manufactured with acceptable costs. The result has produced a final solution with a very good compromise between energetic performances and minimization of costs at industrial level. The results open interesting perspectives for the constructal law to become the core of an effective methodology of an industrial design which can couple perfectly with the modular approach which is currently the major part of industrial companies.

Zero Emission Temporary Habitation: A Passive Container House Acclimatized by Geothermal Water

A container mobile housing system denominated ZETHa (zero energy temporary habitation) is acclimatized by water circulation inside the external walls of the building. A general design of the building has presented and constructive solutions are presented to minimize thermal bridges. Energy dispersions calculations have been performed both for the wall and the whole building. Energetic contribution by renewable energy plants has evaluated to get the condition of passive building. This evaluation will also consider appliances needs. Wellness conditions have evaluated with satisfactory results.

Structural feasibility analysis of a large non-conventional stratospheric non-rigid airship

In the last years, a renewed interest in airships has led to an extensive research to study possible new applications. Such renewed interest is due to the main benefits inherent to airships, primarily its low energy consumption and hovering capabilities. In this line, the MAAT project aims to design a novel green air transport system. MAAT is conceived as a system of two type of airships, the so-called Cruiser, which stays at a constant 16 km altitude and displaces horizontally; and the so-called Feeders, which perform linking operations between ground and the Cruiser. Due to its mission requirements and the objective to generate the totality of energy by solar panels, the Cruiser conceptual design results in a large non-conventional airship. In this paper, the structural feasibility of a non-rigid large non-conventional airship is researched. Finite Element Analyses combined with a literature study have been conducted, aiming to elucidate the effects of size and non-conventional geometry on the envelope stresses. Such analysis reveal the challenges on finding weight-efficient solutions to control the envelope shape, as well as a linear stress increase with the size of the envelope as a consequence of the internal overpressure. Considering the findings, a new solution is proposed: the application of Tensairity beams as structural elements of the airship keel. Tensairity is a new lightweight structure based on the Tensegrity concept: it is based on the functional division of the existing elements, aiming to maximize its efficiency. A Tensairity beam is made of tension and compression elements connected by an air beam that stabilizes the system. In this paper, a large Tensairity torus withstanding air drag force has been numerically studied, aiming to deduce if the Tensairity concept can be applied in these new conditions. The main effects of larger dimensions and a torus-shaped structure have been characterized in order to design a preliminary Tensairity structure. The Tensairity structure has been compared to a HEA profile beam, concluding that the Tensairity principle is reproducible in the studied conditions. Moreover, an analysis of the influence of the air beam radius shows a significant decrease of the struts stress and of the beam deflection as the radius beam is increased. These results validate the possibility of applying Tensairity as an alternative solution for airships structure, although more research and optimization is needed to validate such hypothesis.