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Multibody Advanced Airship for Transport

Periodic Report Summary - MAAT (Multibody advanced airship for transport)

Project context and objectives:

Air transport is a global market with a huge potential for growth. The aviation traffic is predicted to grow dramatically in the next decade particularly in the emerging markets. However, the market of air transportation is overloaded because of several reasons. There is not enough space to build new airports close enough to large cities, the airspace is also overloaded, the fuel consumption and, thus, emission and noise regulation limits restricts significantly the air transport usage. Airship transport solves most of these problems as it can offer the brilliant solution to get more passengers and cargo into the air and thus reducing the pressure on the ground transport links.

The 'Multibody advanced airship for transport' (MAAT) project aims to investigate aerial transportation possibility by airship based cruiser-feeder system. MAAT is composed by tree modules:

(a) the cruiser, called photovoltaic transport aerial high-altitude system (PTAH), is a heavy-payload and high-quote cruiser which remains airborne on stable routes;
(b) the feeder, called aerial transport elevator network feeder (ATEN), is a vertical take-off and landing (VTOL) system which ensure the connection between the cruiser and the ground;
(c) the vertical airport hub, called airport hub for airship (AHA) is a new concept of low cost vertical airport hub joinable by ATEN, easy to build both in towns and in logistic centres.

The feeder can lift up and down by the control of buoyancy force and displace horizontally to join to cruiser. In particular, MAAT aims to define:

(a) a systemic and organic solution for the transport based on the cruiser / feeder air vehicles;
(b) design an airship based cruiser / feeder system completely fed by photovoltaic energy;
(c) the best type of propulsion for the cruiser, considering centralised options designed to supply the problems connected with the propellers at high altitudes, due to the rarefied atmosphere, in order to ensure a simple control during cruiser / feeder engagement operations;
(d) the optimal feeder and cruiser architecture both for their specific operative conditions and for engagement and linking operations;
(e) the structure and interconnections necessary for docking operations and safe transferring operations passengers and goods from the feeder to the cruiser and vice-versa.

MAAT is a green system due to the complete absence of emission, such as carbon dioxide, as it is powered by photovoltaic systems. The operational speed of the MAAT cruiser is estimated about 200 km / h in the calm air atmospheric conditions. This means that the speed could be about 100 km / h when high-frontal winds are encountered and 300 km / h when high-back winds are present. Whereas, the operational altitude has been evaluated between 15 - 16 km, and on the basis of the atmospheric conditions, could range between 13 - 17 km.

MAAT is an ideal vehicle for connecting urban centres worldwide. The vertical take-off and landing allows stopping at urban contexts, thereby minimising the delivery times. MAAT airport hubs result in a reduced consumption of soil due to air transport, which does not need long runways. Also, airport hubs can be located more closer to town centres and thus could reduce the passenger's travelling times.

Project results:

During the first 18 months, the following research and innovation related activities were implemented in a coordinated manner in order to design iteratively the MAAT. Research activities encompass 9 interrelated work packages (WPs). The main activities and findings are summarised below:

WP2: Overall system design

The WP defines the general design of the system both in terms of shape and features by cooperating with other WPs to produce the best possible compromise solution from the different specific solutions. The design of the system presents a lot of difficulties because of tree different contrasting requirements, which are the energy self-sufficiency by photovoltaic electricity, the minimisation of volumes and weights, and the maximum safety. Different preliminary architectures has been produced, converging to the architecture, which has been approved by all partners. On the basis of such teamwork and related results from the respective WPs, it has been evidenced that some energy related problems are encountered. A novel method of system optimisation, based on the constructal method has been defined and preliminarily tested on a traditional airship shape, and the obtained results have been very encouraging. On the basis of this novel method called constructal design for efficiency (CDE) the system optimisation has been initialised to fulfil the different and conflicting MAAT needs.

WP3: Flight mechanics

WP3 is working in the field of aerodynamics and flight mechanics analysis to define the possible candidate shapes for the Cruiser and the Feeder airships. The computational fluid dynamic (CFD) simulation results provide the aerodynamic characteristic for the designed airships shapes. Physical models provide the behavioural and sensitivity analysis of the airships for the broad spectrum of the variable parameters. Based on the aerodynamic and physical models, the multi objective shape optimisation process and simulation of the engagement operations between cruiser and feeder are in progress.

WP4: Energy and propulsive systems

This WP will identify the best renewable energy power system components, connections and architectures for the MAAT system. An analysis of the impact when operating at very high altitude in terms of life-support systems has been completed along with the impact on the MAAT systems under various day/night operating scenarios (including latitude and seasonal variations). A lab demonstration rig is currently being built to enable a detailed modelling by using hardware in the loop (solar arrays, fuel cells, electric drives), to enable assessment of each potential design, and to provide suitable propulsion systems for the scale demonstrator. Each task has been completed according to the programme and the milestone (M21) 'hardware demonstration delivery target' will be met.

WP5: Controls and telecommunications

MAAT control and telecommunication system is required for correct the manned and unmanned flight. Mathematical model is defined and adequate description provided for MAAT. The designed control algorithm uses this mathematical model and performs the flight according to the current mission. The implemented control algorithm is the control code. The hardware implementation gives the necessary computing resources and input data acquired from the sensors to be used by the control systems. The designed telecommunication system organises the proper interaction between the cruiser and feeders.

WP6: Cruiser / feeder docking and joints

The modelling and simulation of the cruiser / feeder docking process requires the completion of the main design activities within WP2, WP3 and WP4. The analysis of the cruiser / feeder engagement system depends heavily on its operational procedures, which are the main focus of the current undergoing research trying to reduce the present instabilities due to the relative motions of the both airships (cruiser / feeder). During such operation the movements of both airships need to be synchronised and coordinated simultaneously in order to achieve the required joint accuracy. The expected WP6, outcomes are in process to be achieved, as follows:
(a) preliminary analysis of cruiser feeder engagement methodologies;
(b) possible problems and effects on system stability during engagement operations analysis of cruiser feeder docking and joining systems.

This is a very pioneering work, as in our knowledge the automatic docking is only successfully implemented for the space stations. There are intermediate results available as reported in detail in the WP6 Intermediate relation deliverable.

WP7: Cabins, cargos and transfer systems

Docking in the stratosphere. The MAAT cruiser / feeder concept necessitates rendezvous and docking operations at the stratospheric altitude, in order to facilitate mobility and transfer of people and goods, which is significantly complex task never attempted before. New advanced technologies, equipment and systems, as well as the safe docking procedures must be put in place. Feeders will transport passengers and goods from the airship hub airport (AHA) to the cruiser and back. Work conducted includes conceptual design work, several reference projects for cabins, cargos and transfer systems along with the associate analysis, including the wind tunnel testing to support control algorithm development and their use in the flight simulator environment. An automated RoboCart system is proposed to enhance passengers experience during the whole travel, from the departing airport to the arrival or transferring one.

WP8: Concept testing and demonstration

This WP will realise three-dimensional (3D) and virtual reality demonstrations of the whole system, using the simulations of WP2 and WP3. WP8 will also produce a reduced scale prototype of the cruiser feeder system to demonstrate the system feasibility and to show its operability. WP8 is focalised on the state of the art about airships and on a complete description of the criteria used for materials trade off and a general discussion of how to obtain an optimal shape both for feeder and cruiser. A first layout of cruiser and feeder demonstrators has been found and a brief comparison between different solutions has been carried on. The control system structure for small-indoor airships for autonomous flight and docking has been also put in evidence. A demonstration in an indoor environment will be performed to demonstrate the docking in flight between feeder and cruiser.

Through dissemination and exploitation activities (WP9), the consortium has contributed to raise the expected impact of project. Dissemination activities are mainly related to the publishing of the project results (including visibility activities) while exploitation activities are put in place to ensure that the results of the project will be reused in the future.

In order to promote the MAAT concept an intensive dissemination campaign is put in place, by targeting different countries and languages. Outreaching actions are aimed to raise the awareness of the citizens and policy makers by means of press-releases, web news, press-cuttings, public presentations, blogs and preparing brochures and videos to illustrate the MAAT system, impact and rationale. Website and social media technologies are also used to spread news and information. Scientific dissemination takes place by usual means of science such as publishing in journals and presenting papers at conferences and workshops at European Union (EU) and international level. The consortium is also directly organising several dissemination events. A workshop entitled Cruiser feeder airship and innovative propulsion for greening the future EU transport is planned on 26 April 2013 at the aeronautics fair AERO 2013 in Friedrichshafen. Further on, a mini-symposium on Multibody Advanced Airship for Transport will be organised as part of EUCASS 2013 5th European Conference for Aeronautics and Space Sciences, (1 - 5 July 2013 in Munich). Last but not least, the consortium is also contributing to organise a special session on the unmanned aerial vehicles (UAV) issues, to take place at the SAE Aerotech 2013 (24 - 26 September 2013 in Montreal).

Bilateral meetings are also taking place with industries and other research and development (R&D) centres interested in prototyping, technology validation and downstream of the MAAT results. All these activities are being coordinated within WP9 which is devoted to dissemination, technology transfer and networking for the after-project sustainability.

Potential impact:

The realisation of MAAT would lead to a revolutionary change in the passenger and freight transport, using a climate-neutral drive-propulsion system. MAAT is an environmental friendly, low cost infrastructure, with high capacity and flexible transport system offering a unique and global solution to all the strategic objectives for the improvement of the long and middle range transport solutions. The MAAT cruiser / feeder system will simplify the air traffic management and the access to the air transport, by making it a part of the urban transport, through a new concept of the airport hub, which has a vertical extension, reduce consumption of soil and is suitable to be installed in the proximity of many existing intermodal connection centres situated in the urban environment.

MAAT conceptualises a radical new greener air transport system and infrastructure, and offers a completely new way of travelling by allowing point to point connection, especially, for long distances while addressing the current 'missing link' between speed and fuel consumption in the aerial transport. The system based on the cruiser / feeder vehicles offers a flexible shuttle service for long and middle range air transport, with the great advantage of dual mode operation.

Amongst the most significant advantage of the MAAT system which depends on its specific production and transformation cycle we find its particular energy source:

(a) the PV system that during daytime produces hydrogen and oxygen;
(b) hydrogen-based fuel cells that during night supplies the electric energy needed.

The autonomy of the cruisers flight is enormously superior to any airplane, but logistical fluxes of the people and goods from one cruiser to another need to be defined in order to put forward the MAAT concept as the worldwide connection networks with great potential to open new frontiers to worldwide logistic of network system. The main area of application is the passengers and cargo transportation, capable of carrying the very large payloads, which are focused on the need to move the cargo loads for which the conventional air transport is too expensive and sea transport too slow. MAAT could also be useful in the developing countries, where airports, sea ports and road infrastructure are lacking the respective infrastructures. In addition, MAAT findings can be transferred to other sectors such as aerial telecommunication, stratospheric surveillance, earth, atmospheric and close space scientific research, search and rescue activities and other related areas such as ground and sea transportation.

The MAAT principles are: safety, efficiency, sustainability and higher level of comfort during flight due to the larger surfaces when comparing with the traditional airplanes. MAAT encourages innovation, in order to increase the passenger choice, schedule flexibility, and reduce accident rates. The undertaken research include the adaptation of the airport and air traffic operations to 24/h utilisation, at the acceptable community noise levels, since the electric propulsive system of the feeder will drastically reduce the acoustic impact of the air transport on the towns and human communities, where they will be operating.

The new concept of the AHA airport can be easily deployed in the urban environments, and in correspondence with intermodal transport nodes. This new philosophy will permit to the air transport to break the traditional access barrier which is constituted by the noise production and the necessity of long runaways, thus allowing for the reduced soil consumption and in addition, being easily integrated within the existing urban transport infrastructures.

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