Speedboat100
Banned
It would be cool to recharge the plane remotely flying low in some kinda electric field.
Why battery-powered aircraft will never have significant range
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It would be cool to recharge the plane remotely flying low in some kinda electric field.
I ain't saying it is likely but it is more probable than some of the battery schemes I have read about.
Maybe rotorcraft are the more efficient way, use many huge static generating rotors and with a little silk and a cat you could stay up indefinitely. Well maybe a little more scientific than the silk and cat method but nobody's knows the right way to that yet so as good a guess as any.
Bille Floyd
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Your correct on that point ; but the way, and speed that knowledge
is processed is a lot faster , giving a guy a lot more of a library to draw
from, when developing new technology. Now one person is content
in watching cat videos, with that technology , and the next guy is
developing a vaccine for covid ; it's kinda all in how ya want to use it.
Bille
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Roughly a factor of 4 and you'd be at the original Cri-Cri (9hp a side-twin engine) for one full size person. With currently flying electric examples.
You are aware who windward performance is and their previous accomplishments? Greg Cole is the designer of the Perlan, Sparrowhawk, Duckhawk, Lancair Evolution, etc... I know Greg Cole personally. Literally no one in the world I would trust more with aircraft performance predictions...
The SparrowHawk itself is calculated to cruise level flight at ~3-4kW. With 100kg of drive and batteries that could be a 500+mile platform also.
Greg gave a fantastic talk at a previous SAS.
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Why fly low? I recall a Popular Mechanics article about aircraft powered by ground-station microwave beams. Wish I could find that article; it was probably in the late '80s.
P.S. tell Mom I'm sorry about that Radarange that never worked again...
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pictsidhe
Well-Known Member
Lithium is not getting replaced as an anode. It's physics, Jim.
Oh, well, chemistry...
There is scope for improvement with cathodes. The holy grail is probably air. Zinc air primary cells have been in use a long time. Very popular in hearing aids. There have also been aluminium air cells. Primary again. Both are somewhat like fuel cells.
If rechargeable Lithium air cells can be developed, that would be the end of the road.
Oh, well, chemistry...
There is scope for improvement with cathodes. The holy grail is probably air. Zinc air primary cells have been in use a long time. Very popular in hearing aids. There have also been aluminium air cells. Primary again. Both are somewhat like fuel cells.
If rechargeable Lithium air cells can be developed, that would be the end of the road.
Speedboat100
Banned
Haig Minibat weighed less than 40 kilos and had a combustion engine.....are you saying it was not made of matter ?
DangerZone
Well-Known Member
This has been done before, and Nikola Tesla wrote about this many years ago. Wireless networks use the same principle, although with higher frequencies and lower power settings.
However.
There are transmission energy losses. Huge losses. Only up to 85% of energy can be remotely sent with the existing technology. This means losses are 15% or more. People usually fail to see how huge these losses are, and what they turn to.
As an analogy, let's use a typical 100kW engine. That's 134 HP, like the new Rotax turbo typically found in newer aircraft engines. That would be 15kW of power, wandering around as a power surge. Can people imagine this much power?
A stove owen with an open fire is typically around 7 to 8 kW of heat. In other words, if the 15kW losses of a typical aircraft engine become concentrated at some point for any reason, a pilot might get fried by the huge amount of heat.
An airliner requires Mega Watt hours (MWh) of energy to fly around. These losses would simply be too huge or complicated to substitute the cheap energy source (oil) already used worldwide. The losses rise exponentially with distance, too.
If something is too complicated or dangerous, it will rarely see wider usage. There were electric aircraft in the past, powered by nuclear reactors. It seems this idea reached a dead end in the 1950s, and got ditched for its complexity.
Convair NB-36H - Wikipedia
Speedboat100
Banned
This has been done before, and Nikola Tesla wrote about this many years ago. Wireless networks use the same principle, although with higher frequencies and lower power settings.
However.
There are transmission energy losses. Huge losses. Only up to 85% of energy can be remotely sent with the existing technology. This means losses are 15% or more. People usually fail to see how huge these losses are, and what they turn to.
As an analogy, let's use a typical 100kW engine. That's 134 HP, like the new Rotax turbo typically found in newer aircraft engines. That would be 15kW of power, wandering around as a power surge. Can people imagine this much power?
A stove owen with an open fire is typically around 7 to 8 kW of heat. In other words, if the 15kW losses of a typical aircraft engine become concentrated at some point for any reason, a pilot might get fried by the huge amount of heat.
An airliner requires Mega Watt hours (MWh) of energy to fly around. These losses would simply be too huge or complicated to substitute the cheap energy source (oil) already used worldwide. The losses rise exponentially with distance, too.
If something is too complicated or dangerous, it will rarely see wider usage. There were electric aircraft in the past, powered by nuclear reactors. It seems this idea reached a dead end in the 1950s, and got ditched for its complexity.
Convair NB-36H - Wikipedia
en.wikipedia.org
Reichelt flew with just 750 watts of power.
PagoBay
Well-Known Member
Embry-Riddle talks to Paul Bertorelli of AvWeb about why Hybrid Drives are the interim necessity.
Yes the electric car was developed 1st - and then lead acid batteries for how many years?? But intense research on battery chemistry only really started with Goodenough around 1980 with lithium and then I believed it relaxed a bit and is now really picking up again because of the success of Tesla.
It is the overall simplicity of a battery that attracts investors, nice neat simple package. Until we get to the stage of the hybrid hydrogen fuel cell that Arnold pulled out of his chest or Kyber crystals , I think the battery will be the main focus for some time and I am betting on a some smart scientist to come up with a combination from the 118 elements on the periodic table that do the job.
Cheers
"Necessity?” We've got very capable planes with a lot of mission flexibility that use internal combustion engines alone. Hybrid setups are a "necessity" for most current missions only if we first decide, for whatever reason, that electric propulsion is a "necessity."
I don't see how hybrid would be the end solution, just a way to experiment with electric and not run out of power in twenty minutes or an hour or whatever. Energy density isn't the only problem to work on.
Dan Thomas
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It's hasn't flown and kits are being sold. Not my idea of responsible development and testing. I am old enough to remember too many cases of this sort of thing.
The thermodynamic efficiency of commercial aircraft turbofan engines is over 55%, that is hard to beat by any "hybrid". Electric propulsion becomes a "necessity" only if adds a functional performance that cannot be realised otherwise, e.g VTOL or extreme STOL so the runways can be a fraction of the size they are now.
Speedboat100
Banned
I am currently designing and testing a small electric AC concept.
Lotsa questions rise.
How do I keep the cockpit warm in a cold country ( summer is no problem ) or at high altitude ?
How do I keep the window open if it freezes.
Is there light way to make flaps ?
Is there simple way to trim all flying elevator.
If I want to make it lite...what is the minimum G-load it ought to withstand as a motorglider.
Lotsa questions rise.
How do I keep the cockpit warm in a cold country ( summer is no problem ) or at high altitude ?
How do I keep the window open if it freezes.
Is there light way to make flaps ?
Is there simple way to trim all flying elevator.
If I want to make it lite...what is the minimum G-load it ought to withstand as a motorglider.
Dan Thomas
Well-Known Member
- Joined
- Sep 17, 2008
- Messages
- 7,345
Aha. Reality sets in...
