My work. Like a diesel electric locomotive of the sky.
Won’t satisfy the greenies though, and likely won’t save enough fuel to merit the extra expense and complexity.
As I have stated before, batteries won’t work on airplanes. Heck they barely work in cars where the weight penalty is much less. Ideas like this and fuel cells may be able to work but are not likely worth it. Fuel remains cheap and plentiful and should be used.
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Seems like too large of an aircraft to switch it to a single engine… those nacelles are huge, how about 2 self contained hybrid systems, one in each nacelle? I can’t imagine the cabin noise with a large turbine and generator mounted in it (yes, I know, but APU’s are relatively small).
Science typically moves forwards in fits and starts. Then reversals. I forgot the number of failures Edison experienced before he finally hit on the right combination of factors in his pursuit of creating a “light bulb”. Human achievement is typically the result of perseverance, skill, and luck. One or more of those who are pursuing the idea of electric propulsion for aircraft will find a good (not necessarily optimal) solution.
Bjorn has detailed the problem with large batteries on aircraft, in the LeehamNews forum.
But deHC and PWC will get greenie points from government, deHC will get publicity, and the owner of deHC will be happy given her background.
LeehamNews forum allows edit for several minutes after posting, it is using WorstPress.
FoubarBook allows editing anytime.
But Edison was working on something useful.
The physics of greenhouse gas molecules limits the amount of temperature rise that CO2 can cause to a small amount, most of which has already been realized. That’s because of the ‘saturation’ effect of energy flow from overlap of absorption-emission spectra of carbon dioxide and the most common greenhouse gas, dihydrogen monoxide (water vapour).
Reality is that the climate is not warming at an alarming rate, and sea level is not rising at a rate significantly faster than it has been since the end of the long cool period around 1750AD. (See PSMSL.org for government databases.) Records of surface temperatures are incomplete and contain unexplained ‘adjustments.’ I’ll instead go with traditional weather balloon thermometers and satellite sensors. Climate was stable during the Medieval Warm Periods when Vikings farmed southwest Greenland.
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Somehow I can’t see the energy advantage of inserting a generator-motor conversion step into the middle of the power generation and application chain. In ground vehicles such as trains or construction equipment the added flexibility of precise power control & application is an advantage, but in an aircraft, not so much. Mostly you just want to feed everything you’ve got directly to the props. Probably some aerodynamic advantages, but that seems to be about it.
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Personally I have no affection for Edison. He was a dick. May have been saved by Grace but that’s between him and the Lord. On Earth he was a dick. I think much of his success was intellectual property theft and manic trial and error, not scientific process. Like the analogy of a monkey trying out the alphabet if given enough time on the keyboard.
Regarding the Wrights they were scientists and amazingly hard workers and innovators. I never would have made fun of their machine as it was the best in the world at the time. A nearly infinite step forward from no airplanes at all. These full scale RC electric fliers are a step backwards.
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Great question John. I think the theory goes like this: Airplanes need 100% power for takeoff. They need about 90% for climb, and about 80% for cruise. So if you design an airplane with a slightly smaller engine that flat-out produces 85% of the power needed, the fuel consumption is 15% less than an airplane with a full-size engine. You let the engine run flat-out all the time. During the takeoff, you’ll need the extra 15% energy to come from an onboard battery. During climb, you’ll need to supplement the engine by 5% with energy from the battery. During cruise, the generator is capable of powering the airplane fully and also slightly charging the battery. During descent, the props can recover energy to charge the battery (and the generator still running flat out is aggressively charging the battery). So the battery is charged and available for a potential go-around at the destination, or possibly ready for the next flight not long after landing.
Indeed, the Wrights were excellent developers - learned, tested including in own wind tunnel,
They probably did not understand an earlier researcher’s formula, but succeeded by testing to develop their own
While a government funded perfessor in Washington DC failed miserably.
Heavy criticism of the Wrights, including dishonest attempts to show them wrong.
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Ground vehicles benefit from recapture of kinetic and potential energy in braking.
And from more torque due energy surge available from battery.
And I guess from flexibility, you mentioned wheel/suspension geometry, I note smoothness may be a big factor - noting that diesel-electric locomotives are standard, not diesel-direct.
I’d have to crawl through energy during descent of an aircraft, normally the potential energy of height and mass is dissipated in drag. (So warms aircraft and air.)
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The “CO2 saturation effect” is a fallacy, based on a misunderstanding of heat transfer in the atmosphere. For details, see https://skepticalscience.com/saturated-co2-effect.htm
In brief, yes, the CO2 absorption in the earth’s atmosphere has been saturated for a long time. Only the upper atmosphere radiates heat into space (in the absorption wavelength band). In the lower atmosphere, heat is transferred upwards by convection.
Increase the CO2 percentage in the atmosphere and you raise the altitude of the convection/radiation transition. To maintain the same heat radiation, you need the same temperature, but at a higher altitude. Because of the atmospheric temperature lapse rate, that means you need a higher surface / sea level temperature.
There’s a good argument to stick with fossil fuels for planes in there. If you electrify the cars, the need to change the planes will go away. Also, we know that the market will not want to change. Couldn’t we already make more efficient airliners using turbo props and lower speeds! The Bear bombers are efficient, right? I don’t know, maybe that’s wrong.
I do know that electric self launch gliders are a great idea, and anyone interested in expanding the pilot population really ought to be pushing those planes.
Well stated Keith, I wish more scientist were fact motivated instead of Politically motivated. But facts don’t provide funding.
The Wrights fully understood Sir George Caley’s research on lift, published 100 years before Kitty Hawk. They built on (and acknowledged) that research. The Wright’s genius was in developing a power plant to get the aircraft airborne and more importantly how to control it (wing warping) once up there.
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And the usage of the wind tunnel.
Powered flight needed the development of the ICE. Still does.
Direct energy recovery from the props during descent would not be a huge factor. But the reduction in propulsive power needed means that suddenly the generator has tremendous power available for battery charging during the descent.