Sun-H2, F.A.Q.
Why use an electric motor unmanned aerial vehicle (UAV) ?
For aerial observation missions, it is not necessary to fly quickly. This is not a "race for power". The idea is to conserve the greatest possible autonomy, to fly for a long time at a high altitude, even over the usual airways. This means consuming a minimum, using a maximum of free solar energy and consuming a minimum of one's "own" petrol. The brushless Sun-H2 electric motor weighs 1.5 kgs, uses 10kW and gives approximately 90% output.
Why choose this rather uncommon type of "flying wing" ?
Electric motorization requires a parsimonious use of energy. It is therefore necessary to make use of the most appropriate aerodynamic concept that allows for flying slowly while simultaneously providing both good aerodynamic performance, and a good payload capacity. For various reasons, only the Swift "flying wing" is suitable for this type of application.
Why mix two sources of energy to produce electricity ?
To fly in the daytime, solar energy is sufficient to propel the airplane, at least under sunny conditions, or at an altitude above the cloud cover. Yet if one wishes to travel a long distance, and prolong the flight into the night, a clean, alternative energy source is necessary. The most suitable one at present is, without contest, the hydrogen-powered fuel cell.
Why not use batteries ?
It is possible as serious progress has been made in stocking electric energy. However, prolonging night flight would require an extra load of batteries, an unacceptable condition for the plane's spec. It is necessary to recharge the batteries during the day by increasing the surface of the solar panels. This equation would bring us to imagine a gigantic drone which would generate numerous problems in handling, stability, transportation and development budgets and an overpriced sales price.
What is the size of the Sun-H2 airplane ?
A 12.5-meter wingspan. We currently have a flying machine that is logistically acceptable.
What are the specifications of the Sun-H2 ?
MTOW: Maximum take-off weight: 120kg
Wing area: 12.5m2
Wing Loading: 10 kg/m2
Speed Range: from 10 to 30 m/s at sea level
Initial Rate of Climb: 5 m/s
Maximum Motor Power: 10 kW
Fuel cell power: 4 kW
Hydrogen tank weight: 33kg
Hydrogen: 4kg
Maximum Solar Power: 13.2 kW
Photovoltaïc cells : 15m² (wing, POD, winglets)
Propeller: two-bladed composite variable pitch propeller, 1.36 meter
in diameter
Maximum Propeller Rotation Speed: 2500 revolutions/minute
Landing Gear: Retractable tricycle
Autonomy: 96 hours.
Remote controlled flight.
Which future for electric aviation?
The depletion of fossil fuels on the one hand and the emissions of CO2 in upper altitudes which causes a greenhouse effect that are more harmful than those emitted on the ground will in the long term oblige aeronautical manufacturers to envisage different energies than gasoline or kerosene for aviation. Ninety years passed between the crossing of the English Channel by "Blériot" and the introduction of the Airbus A380. Did you know that the next fighter of Dassault will be an UAV ? We leave it to you to imagine the future of aviation...
