It seems to me that the introduction of electric drive in aircraft and their engines could also be beneficial in a number of ways. This could be done by reducing the bypass ratio of the jet engines, and instead gather the energy produed as electricty. The power would then be diverted to motors connected with their own fans.
Advantages:
- Felxibility in design - electric motors could be installed on top of the wing or elsewhere
- Safety - In case of a jet failure, power could be diverted from the running engine, or battery
- Noice reduction - The larger jet cores could be better shielded, or placed on top of the aircraft
- Electric taxiing and ground operation. Taxiing backwards (remember to add a mirror!)
- Energy regeneration during descent and braking
- Grid or battery powered take off boost
- Maintenance cost reduction - electric motors require less maintenance than jet engines
- Solar power - for very slow moving regional aircrafts - solar power could be significant
- Air brakes - the elecrical engines can be reversed when braking power is needed.
I assume in this that a larger jet core, with a smaller attached fan, would be able to produce energy just as, or more, efficient compared to smaller cores.
The use of batteries in the aircraft might not be usefull, as their weigh could potentially cancel out their benefits when regenerating energy or boosting during takeoff. If the right technology and size is found, however, it could still be a valuable addition.
My initial idea for electric drive on aircraft was in the context of large airliners with more than two engines. Here, two of the engines could be replaced with any number of electrical fans. On smaller aircrafts with two engines, the addition of electrical fans could also be usefull and the jet cores could perhaps be moved to the tail, with the fans on the wings.
Searching the web would give you this:
http://ewh.ieee.org/tc/csc/europe/newsforum/pdf/LuongoC_2AP01.pdf
Update: After actually reading the document above I realised that todays electrical engines have a power to weight ratio 6 to 30 times lower than that of the jet core. The copper windings simply produce too much heat to enable more powerfull engines. This complicates things somewhat, but the suggested solution seems to be to use superconducting matrerials to produce the motors. This looks promising for the future!
