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The potentially revolutionary Celera 500L aircraft

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Re: The potentially revolutionary Celera 500L aircraft

#101

Post by brunooo »

Retric wrote: post #89
qzw wrote: post #58

Earlier quoted context omitted.

Definitely some extraodinary claims that will require extraordinary evidence to prove. Especially getting 20+ mpg for 4500 miles, while flying at 450mph, which is near the top end of what piston/propeller aircraft are capable of. For reference, the P51 (one of the fastest fighters of WWII) had a comparable top speed. The Piaggio Avanti [0] has a somewhat similar design and top speed (460 high speed cruise), but has t…

The Piaggio II ( https://www.aircraftcompare.com/aircraft/piaggio-p180-avanti... ) is missing several modern aerodynamic and efficiency features like winglets and gets 15MPG and has a 1600 Mile range. Significantly beating it’s fuel efficiency at similar speeds seems reasonable just eyeballing the two designs. Getting the full 20MPG at 450MPH might be a stretch, but it’s not all that unreasonable. Also, higher aerody…

I’m not sure those mpg numbers are correct: the more fuel efficient Piaggio EVO update, with winglets etc, in the extended range version can hold about 450 gallons of Jet A and has a 1770nm range, so even with plenty of reserves that doesn’t get it anywhere above half of 15mpg (from what I can find IFR reserve comes out to 75 gallons, thus 4.72mpg nautical or 5.4 statute).

Which is why the jump in efficiency would be so extraordinary.

Re: The potentially revolutionary Celera 500L aircraft

#102

Post by dmix »

karlkatzke wrote: post #80
_uy6i wrote: post #47

Earlier quoted context omitted.

3,300 feet in not a long runway - it means you can access ~80% of the ~5,000 runways in the US. On the the other hand A 777 needs 8,000-10,000 feet meaning it can only access https://www.cia.gov/library/publications/the-world-factbook/... https://en.wikipedia.org/wiki/Boeing_777#777-200LR

3300 feet in balanced density conditions. You’d better not bet on 3300 feet in Phoenix during the day time most of the year. Or Denver for that matter.

Sorry for the amateur question, but why does it take longer to take off in hot places? Doesn’t heat generate lift, like in gliders crossing hilly terrain? Or is it the heat offsetting with the cooler ground that helps, so you’d need a greater amount in hot places?

Re: The potentially revolutionary Celera 500L aircraft

#103

Post by desdiv »

davidgould wrote: post #60
baybal2 wrote: post #43

Earlier quoted context omitted.

It is a V12. Historical military V12s had a feature of two bank redundancy. One row of 6 cylinders can be shut down along with its pumps, cooling, etc. And I have a big suspicion that they use two of these engines inside.

V* engines share a common crankshaft with both banks, that's the V part. Please cite any specific V12 aircraft engine that can have one bank of cylinders shut down. I don't believe one exists.

>Please cite any specific V12 aircraft engine that can have one bank of cylinders shut down.

The RED A03 Engine[0], which is what this sub-thread is about.

>Two cylinder-bank redundancy concept for high safety.

>Robustness and safety are incorporated into the engine design. The two 6-cylinder banks are capable of independent operation. All critical engine sub-systems are mutually-independent.

[0] https://red-aircraft.com/

Re: The potentially revolutionary Celera 500L aircraft

#104

Post by rolph »

dmix wrote: post #102
karlkatzke wrote: post #80

Earlier quoted context omitted.

3300 feet in balanced density conditions. You’d better not bet on 3300 feet in Phoenix during the day time most of the year. Or Denver for that matter.

Sorry for the amateur question, but why does it take longer to take off in hot places? Doesn’t heat generate lift, like in gliders crossing hilly terrain? Or is it the heat offsetting with the cooler ground that helps, so you’d need a greater amount in hot places?

hot air rises but its less dense thats why it rises, so it has less lifting capacity thermal updrafts are different they are a larger scale phenomenon

Re: The potentially revolutionary Celera 500L aircraft

#105

Post by unoti »

dmix wrote: post #102
karlkatzke wrote: post #80

Earlier quoted context omitted.

3300 feet in balanced density conditions. You’d better not bet on 3300 feet in Phoenix during the day time most of the year. Or Denver for that matter.

Sorry for the amateur question, but why does it take longer to take off in hot places? Doesn’t heat generate lift, like in gliders crossing hilly terrain? Or is it the heat offsetting with the cooler ground that helps, so you’d need a greater amount in hot places?

> why does it take longer to take off in hot places?

When the air is cold the air is more dense. This has an impact both on how much lift is generated per amount of speed over the wings, and also impacts how much power the engine/carburetor are able to generate.

Re: The potentially revolutionary Celera 500L aircraft

#107

Post by 55873445216111 »

AmVess wrote: post #31
jdhn wrote: post #18

I'm kind of curious as to why they went with the engine that they did instead of something based off of Chevrolet's LS engine architecture, but tuned for the unique demands of planes. Seems that they place efficiency as a high standard, and the LS series of engines are pretty efficient in terms of how much power they generate vs how much space the engine takes up.

The engine in the Celera is designed for aircraft use. It is a turbocharged turbodiesel. In order to get the Chevrolet V-8 to work at altitude, you'd need to put a turbocharger on it which would destroy the fuel economy, especially in this application. Also, automotive engines are not designed to withstand the heavy duty cycle that this aircraft requires.

Actually, the Chevrolet LS series small block V8 has been used in airplanes and helicopters. The only automotive engine series I am aware of that used in aviation. http://www.v8seabee.com/. https://en.m.wikipedia.org/wiki/Vertical_Hummingbird

Re: The potentially revolutionary Celera 500L aircraft

#108

Post by generatorguy »

dmix wrote: post #102
karlkatzke wrote: post #80

Earlier quoted context omitted.

3300 feet in balanced density conditions. You’d better not bet on 3300 feet in Phoenix during the day time most of the year. Or Denver for that matter.

Sorry for the amateur question, but why does it take longer to take off in hot places? Doesn’t heat generate lift, like in gliders crossing hilly terrain? Or is it the heat offsetting with the cooler ground that helps, so you’d need a greater amount in hot places?

When it is hot out Air is less dense so the wings don’t generate as much lift.

I believe engines make less power when the air in is hotter too as there is less delta T. Something something Carnot cycle

Re: The potentially revolutionary Celera 500L aircraft

#109

Post by brunooo »

scarier wrote: post #96
nl wrote: post #93

Earlier quoted context omitted.

Much of the improved efficiency comes from the engine[1], which claims "50% lower fuel burn compared to turbine engines in the same power category". The engine company is German and so we can make lots of jokes about German companies' fuel efficiency claims I guess. Nevertheless, it has been around since 2012 and is used in a few planes already, so presumably there is some measurable improvement there or they'd have…

Still, a plane with half the aerodynamic drag and twice the BSFC is only getting 4x the fuel efficiency, not the ~10x they're claiming. Even if they're making a bit of "free" thrust from their cooling system (which has been a thing since WWII), I don't see what accounts for the rest, even ignoring that the Celera likely has a significant increase in frontal area due to the standing-height cabin.

Re “free thrust/WWII”: Real Engineering recently did a great summary of the P47 Thunderbolt intercooler and general craziness of the engine at https://youtu.be/IwqTN5fhMR8

Re: The potentially revolutionary Celera 500L aircraft

#110

Post by sirk1882 »

dmix wrote: post #102
karlkatzke wrote: post #80

Earlier quoted context omitted.

3300 feet in balanced density conditions. You’d better not bet on 3300 feet in Phoenix during the day time most of the year. Or Denver for that matter.

Sorry for the amateur question, but why does it take longer to take off in hot places? Doesn’t heat generate lift, like in gliders crossing hilly terrain? Or is it the heat offsetting with the cooler ground that helps, so you’d need a greater amount in hot places?

It has to do with air density.

Heavy, cold air will generate more lift since it's "thicker" for lack of a better term.

Hot air is less dense. This means it takes more power to move more air.

It's easier to maybe think of the air that you breath as a "liquid" like material comprised of a mix of mostly nitrogen, some oxygen and a little carbon dioxide and other gases. That mix changes with temperature and elevation. Just like the deeper under the ocean that you go, you have more pressure, the lower to the ground you are the more atmospheric pressure you will feel. And the higher that you go, there's less pressure.

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