Electric mobility is becoming increasingly interesting for aviation. Siemens, who is quite active in the area, already accomplished a technology milestone: they managed to develop an electric motor, five times more powerful than conventional engines!
The researchers at Siemens developed a new type of electric motor designed specifically for aircraft that weights only 50 kg yet delivers a continuous output of about 260 kW. The power-to-weight ratio of this engine, which breaks all previous records, opens up the possibility of larger aircraft with takeoff weight of up to two tons and capacity for up to 100 passengers to use an electric propulsion system.
To successfully reduce the engine weight the manufacturer sought a number of developments such the use of a cobalt-iron alloy in the stator resulting in high magnetizability. The rotor’s permanent magnets are arranged in a Halbach array – a special way of positioning the magnets which results in a magnetic flux optimally directed with a minimal use of material. Another weight-reduction technology is directly cooling the conductors by an electrically non-conductive cooling liquid such as silicon oil or Galden.
The combination of an electric motor with a combustion engine allows the use of a turbine that is not only much smaller than the current ones, but can be used with maximum efficiency during flight. “The use of hybrid electric drives would reduce fuel consumption by around 25 percent, with the result that the total costs of an aircraft would fall by about 12 percent,” explains Dr. Frank Anton, head of the electric aircraft team.
Siemens is now working with Airbus in developing even lighter and powerful engines, and if successful we can expect the first hybrid aircraft for up to 100 passengers with electric motor to fly in 2035.
Via: The Engineer