Skip to main content

Novel electric turbines to power the VTOL drone & aircraft revolution

Periodic Reporting for period 1 - Apollo (Novel electric turbines to power the VTOL drone & aircraft revolution)

Reporting period: 2018-09-01 to 2018-12-31

The project Apollo (EU- 827200) proposed by European Sustainable Propulsion (ESP) SAS addresses 3 major issues of Urban Air Mobility (UAM):
(1) VTOL propulsion for aircraft, (2) Electric Aircraft and Helicopter Propulsion, (3) Distributed Propulsion.
(1)VTOL Propulsion for aircraft : For decades, vertical take-off & landing aircraft (VTOLs) have seen their use limited to special purpose applications. The most common examples of VTOLs are the powered rotor aircraft (helicopters) that are very expensive to fly & difficult to pilot. Other well-known VTOL types such as the tilted rotor aircraft (e.g. Bell Boeing V-22 Osprey) or the directed jet thrust aircraft (e.g. Harrier Jump Jet or F35B Joint Strike Fighter) are used exclusively by the military—their high production & operation costs are economically impossible for civilian applications. In order to develop Urban Air mobility, VTOL capability for new aircraft are needed so that they can fly and land easily within cities and enable in-city flight-corridor to de-congestion the land roads.
(2)Electric Aircraft & helicopter Propulsion: Electric propulsion is the key sustainability technology to provide dramatic reductions in aviation carbon emissions. It enables 5-10 times reduction in greenhouse gas emissions with current electricity, and essentially zero emissions with renewable-based electricity. Electric propulsion also provides a technology path for small aircraft to eliminate 100LL (low lead) avgas (aviation gasoline), which is the key contributor to lead emissions globally. It is thus needed that a new type of electric propulsion be designed for rotor-craft and winged aircraft to be powered using electricity and cut the CO2 emissions and other pollutants.
(3)Distributed Propulsion: Distributed propulsion is a type of powered flight propulsion system in which engines are distributed about an aircraft. It increases fuel efficiency, decreases emissions & noise. It also greatly increases safety by removing flight-critical components (failure of 1 engine out of 20 on a VTOL is incomparable to failure of 1 engine out of 2 on a conventional airplane). The limiting factors for the adoption of distributed propulsion is 1) the lack of adequate control systems, 2) yet low battery densities but most importantly 3) low power/weight ratio of engines to sustain heavy payloads.
Conclusion: European Sustainable Propulsion (ESP) is developing the solution to enable further development of the VTOL industry with electric turbines (Electric ducted fans) codenamed Apollo, Athena, Hermes, etc.. They combine high static thrust needed for vertical take-off & landing and allow for Distributed Propulsion to ensure high safety for rotor-crafts and aircraft.
For the Apollo project (EU- 827200) , the ESP SAS Team performed a commercial and market feasibility, to validate the economics and financial viability.
ESP SAS reviewed 33 Urban Air Mobility Projects Worldwide with +135 persons interviewed and more than 10 market studies between 2014 and 2018 cross-checked.
First findings of the study are that the total addressable market (TAM) for Urban Air Mobility (UAM) is predicted to be around $30b by 2027/2030 for Freight & Passengers drones.
It is estimated that $1b is roughly for Passengers drones and $29b for freight and industry. Of this about 24% are currently expected to use electric turbines (electric ducted fans) which would represent an addressable market of $7.2b of Freight & Passengers drones to be equipped with electric turbines (electric ducted fans).
The market at the time of writing focuses heavily on news and eye-catching designs rather than engineering reality or B2B use-cases.
So entrepreneurs responded to Urban Air Mobility (UAM) projects with 47% for the Air-Taxi for passengers’ drones, while only 16% focuses on Freight & Industry and the Air-Bike projects are 16% of the total 33 projects reviewed worldwide.
Propulsion Technology choices are: 43% of projects or flying demonstrators rely on distributed propulsion using fixed-pitch propellers, and 24% are developing technology based around electric ducted fans (EDF) (fixed pitch too) also known as electric turbines, and 21% of the reviewed projects want to use distributed caged-propellers (shrouded-prop) (a mix of fixed and variable pitch). The global scattering of projects per countries is:
49% in USA, Europe 36% (with UK for 15%, France for 12%, Germany for 6%, Hungary 3%) and 6% in Russia.
In term of flight design type (Wing-VTOL, Multi-copter, and custom) over the 33 reviewed worldwide projects: 58% of project are multi-rotor-craft (using either edf, caged-prop, or propellers); 30 % of the projects use Wing-VTOL airplanes design -most of them for passengers drones with 2 Wing-VTOL projects for defense (Valkyrie and Aurora); other projects are looking at VTOL-Jet (XTI) or Air-bikes or fly-board (Zapata).
With 58%, it indicates clearly that low velocity propulsion system used for multi-copter type design may prevail in the short term.
Hence EDF for slow speed – static thrust - might be the best avenue for EDF manufacturers.
European manufacturers may face direct competition of Chinese producers of electric multi-propellers systems and Chinese drone makers.
The total addressable market for electric turbines seems to be higher within the industry and freight segment rather than passengers’ drones multi-copter for the short term.
We think that EDF/e-turbines will probably become mandatory for the civilian Urban Air mobility market in the future.
Major Roadblock is technological: the 500WH per Kg storage capacity of batteries which is expected to be reached by 2030 and will allow electric rotor-craft to fly through the threshold of 30 minutes and may even reach up to 1 hr.
Then the next roadblock will be insurances and airspace regulations. Insurers and Airspace regulators may provide soon frameworks for Freight Drones applications (see the amazon projects and google pilot projects for deliveries) which makes us believe Freight & Industrial Drones applications will pick up market shares first due to these regulatory issues.
CO2 emission and pollutants will drastically be reduced by using small and large drones as the LLNL study demonstrates (publication: Nature).
Keywords: UAM, urban air mobility, electric ducted fan, electric aviation, distributed propulsion, Passenger drone, Freight drone, electric turbine.
The Apollo Project (EU- 827200) confirmed that technology of Electric Urban Air Mobility have the potential to enables 5 to 10 times reduction in greenhouse gas emissions with current electricity, and essentially zero emissions with renewable-based electricity. Electric propulsion also provides a technology path for small aircraft to eliminate 100LL (low lead) avgas (aviation gasoline), which is the key contributor to lead emissions globally. Other benefits will be reduction of TCO for Air transport vehicle between 2 to 10 fold compared to Helicopter and switching to a drone-enabled transport economy will support existing infrastructure (rail, road, underground) to cope with population increase and freight transport increase.
The project also showed that technically electric turbines also known as Electric Ducted Fans (EDF) can now be used efficiently for Urban Air Mobility and for electric Distributed Propulsion aircraft and rotor-craft. The existing Electric Ducted Fans (EDF) have efficiencies around 2kgf of thrust per Kilo-watt of electricity efficiency (from 1 Kgf/Kw from China to 3Kgf/Kw for German EDF manufacturer) while ESP SAS Electric Ducted Fan has efficiency for static thrust up to over 6Kgf/Kw which is an improvement beyond state of the art and that allows for using safe EDF for vtol flight. The EDF provide a new type of propulsion which is way safer than multi-rotors for vtol airplanes or muli-copters. EDF allow for new compact development for Urban Air mobility.
Aircraft-vtol and multi-copter using Distributed Propulsion will also be safer as the redundancy will allow for failure acceptance and so reduce the potential of fatality from air accident.
Urban Air mobility, VTOL aircraft & rotor-craft will be able to fly and land easily within cities and enable in-city flight-corridor to de-congestion the land roads.
It will enable EU citizen to have more choice in mobility and provide efficiency for organisation and provide alternate to the existing infrastructures (rail, road, tubes, etc..) .
ESP Appolo e-turbine for Urban Air Mobility and Distributed Propulsion