New electric aircraft propulsion unit
Join Date: Mar 2009
Location: Perth Western Australia
Age: 57
Posts: 808
Likes: 0
Received 0 Likes
on
0 Posts
Trucks that utilise hybrid diesel-electric drive have been on the market for around 7 yrs at least. There are no really large size units yet, but they will probably appear sometime in the future.
Apologies for the thread drift, but the easiest way to get better fuel economy from trucks is to modify the drivers habits, such that they don't go rushing up to junctions and then slam on their brakes, as if fuel was free (well, it is, to them).
Its the same issue with all technologies, trains drive system, versus road transport etc. Its the usage pattern varience that dictates if a technology will be useful over a product population.
Whats good about some of these "cute" technologys, is that they can be used in a specific market for a decade or so to get data. As material science etc. develops, then the engineering jump into other markets isn't so great.
Join Date: May 2010
Location: EU
Age: 54
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
AC with hybrid electric propulsion
OK, it seems that electrical drive of propellers is on the road ...
But are anybody knowing of an attempt to develop electrical/hybrid "regenerative braking" ?
I mean propellers capable to change pitch to run as RATs along with reversible electric motors switched to generating regime ? I think that on a long descent there are a lot of energy which could be "harvested"
But are anybody knowing of an attempt to develop electrical/hybrid "regenerative braking" ?
I mean propellers capable to change pitch to run as RATs along with reversible electric motors switched to generating regime ? I think that on a long descent there are a lot of energy which could be "harvested"
I mean propellers capable to change pitch to run as RATs along with reversible electric motors switched to generating regime ? I think that on a long descent there are a lot of energy which could be "harvested"
I don't think that's a great idea, in any phase of flight.
Join Date: May 2000
Location: Seattle
Posts: 3,195
Likes: 0
Received 0 Likes
on
0 Posts
Why not? A speedbrake function should be feasible, once the electric prop idea is good enough for deployment. It's little different in concept than flat pitch in a turboprop.
Join Date: Jun 2015
Location: Vilnius
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
I mean propellers capable to change pitch to run as RATs along with reversible electric motors switched to generating regime ? I think that on a long descent there are a lot of energy which could be "harvested"
you are quite right for the propellers, but current electric propulsion is only limited to small jets.
All-electric aircraft ? are we far from an environmental utopia?
Check this out
Join Date: Aug 2007
Location: The Netherlands
Age: 67
Posts: 288
Likes: 0
Received 0 Likes
on
0 Posts
WRONG PERSPECTIVE
AlexD10
Technically it is probably possible to "harvest" electrical energy with reverse generation, but what is the use?
Coming in from high altitude, the aircraft basically glides in at idle power. If the propellers would be used as windmills, then the aircraft would have much higher drag, so the path would be steeper.
In order to have that steeper path available, the aircraft would have to stay at higher cruise level for a longer time, which would require cruise thrust in stead of idle.
Furthermore, in order to store all the harvested energy, the aircraft would have to haul along, all the time, a massive pack of batteries, which would also cost extra energy.
Elecric cars are a "succes" only because of all the government subsidies given on them, keep that bull manure out of aviation please!
Technically it is probably possible to "harvest" electrical energy with reverse generation, but what is the use?
Coming in from high altitude, the aircraft basically glides in at idle power. If the propellers would be used as windmills, then the aircraft would have much higher drag, so the path would be steeper.
In order to have that steeper path available, the aircraft would have to stay at higher cruise level for a longer time, which would require cruise thrust in stead of idle.
Furthermore, in order to store all the harvested energy, the aircraft would have to haul along, all the time, a massive pack of batteries, which would also cost extra energy.
Elecric cars are a "succes" only because of all the government subsidies given on them, keep that bull manure out of aviation please!
But are anybody knowing of an attempt to develop electrical/hybrid "regenerative braking" ?
I mean propellers capable to change pitch to run as RATs along with reversible electric motors switched to generating regime ? I think that on a long descent there are a lot of energy which could be "harvested"
I mean propellers capable to change pitch to run as RATs along with reversible electric motors switched to generating regime ? I think that on a long descent there are a lot of energy which could be "harvested"
Regenerative props will, by definition, create much drag and therefore only be effective as speed brakes. However, as such they will recover at least some energy from an otherwise non-optimum managed descent profile.
Quote:
The powertrain redundancy for the V22 Osprey would certainly be a lot simpler.
The powertrain redundancy for the V22 Osprey would certainly be a lot simpler.
Not necessarily...
The cross-shaft between the props will still be necessary, since it is imperative that they both provide near-equal thrust. OTOH, you MIGHT be able to get an electric motor on the wingtip that is powerful enough, but smaller/lighter than the turbine. Putting those high-current electric wires to the end of the wings will be a problem itself...
The cross-shaft between the props will still be necessary, since it is imperative that they both provide near-equal thrust. OTOH, you MIGHT be able to get an electric motor on the wingtip that is powerful enough, but smaller/lighter than the turbine. Putting those high-current electric wires to the end of the wings will be a problem itself...
Wouldn't two motors on each wingtip provide better redundancy than the cross shaft.
Low current wiring to the wing tips. Step down transformers...etc.
Where there's a will..
