Easy jet prototype | TheaterFire

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Disastrous-Plant-418@reddit

I like it. From what I’ve read, and feel free to correct me, engines with external bypass fans are showing great promise

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DouchecraftCarrier@reddit

My understanding is they're quite efficient but also incredibly loud.

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TheLandOfConfusion@reddit

Hear me out… let’s put another duct around the external fan. And then another set of smaller fan blades external to that.

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FredThe12th@reddit

I think they just invented the turbofanprop.

A high bypass turbofan with external propellers.

I'm sure some P&W or RR engineer in the ❄️70s already patented this madness

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Schmantikor@reddit

External bypass engines technically count as turboprops

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Disastrous-Plant-418@reddit

That could definitely be a challenge. I wonder if different blade shapes could help overcome that

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Healthy_Working_8233@reddit

It's the blade tip speed breaking the sound barrier. In order to move air efficiently, they must move fast. That comes with a lot of noise

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404-skill_not_found@reddit

Part of the why of the rudder configuration. It’s an attempt to direct the noise away from the sides and the ground. Mitigating the vibration effects would be something.

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TacTurtle@reddit

Would make losing a prop blade interesting.

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404-skill_not_found@reddit

Before or after trying to shake the engine from its mounts?

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TacTurtle@reddit

When the blade flies through the tail control hydraulics.

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ratshack@reddit

Yo dawg, we heard you liked failure modes…

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Newbosterone@reddit

Loosing a blade, turboprop or turbofan, is always interesting.

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Uniturner@reddit

Yeah, it’s not the best for redundancy.

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Disastrous-Plant-418@reddit

A constant sonic boom would definitely be a noise issue. Perhaps my optimism is misplaced.

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cmdrfire@reddit

You aren't big enough and there aren't enough of you to get me in that thing again

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Late-Application-47@reddit

Ah, like the Tu-95/114? The 114 was the Soviets' safest airliner...if you don't count hearing damage.

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Kosh_Ascadian@reddit

The engines are at the back, you gotta just fly fast enough to get away from the noise and you're fine!

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Independent_Vast9279@reddit

Supersonic turboprop! The FAA will love it.

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Kosh_Ascadian@reddit

It's got both the words "super" and "turbo" in it's name. Sounds amazing, what's not to love!

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xrelaht@reddit

The Piaggio P.180 Avanti is apparently quite quiet inside. It's just the people on the ground who get bombarded.

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lobstersatellite@reddit

They were incredibly loud in the 80s. I am of unique qualification to say that we have largely solved the noise issues associated with propfans.

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skydivingdutch@reddit

Any chance we'll see them in production in the next 10 years?

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I've heard the new ones are actually a lot more quiet. The old ones didn't have gearboxes, so they spun really really fast and used two contra rotating fans, while the new ones use a single fan with a gearbox and thingies (I forgot their names) behind to smooth out the airflow, reducing drag and noise.

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lobstersatellite@reddit

Stators or OGVs (outlet guide vanes.)

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Hattix@reddit

Unducted fans have been The Next Big Thing for around 30 years now. A little like aerospikes in rocketry.

So far they have engineering issues which have been insurmountable.

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richdrich@reddit

Trident has an aerospike and that's a 70s / 80s design. I understood its mostly to reduce the height of the missile.

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redmercuryvendor@reddit

So far they have engineering issues which have been insurmountable.

The engineering issues - with both unducted fans and aerospikes - are vastly overblown: they have both had operational tests decades ago (e.g. the annular aerospike J-2 in the late 60s), with no real showstoppers.

The problem is they both solve a problem that doesn't really exist.

Aerospikes are more efficient than sea-level optimised nozzles in a vacuum, and more efficient (or rather, less prone to flow separation and RUDs) than vacuum optimised nozzles at sea level - however they are less efficint at sea-level than a sea-level optimised nozzle, and likewise in a vacuum. But if you need one nozzle design that can operate from surface all the way to a vacuum without any moving parts (e.g. actuated bell extensions) an Aerospike is a good option. The problem is, because rockets have multiple stages, sea level engines only ever operate near sea-level for for a few seconds in the upper atmosphere, and vacuum engines only ever operate outside the atmosphere, so an nozzle that can do both is not actually needed.

Likewise, aircraft that need to fly low and slow tend to only fly low and slow, so turboprops are a better option than unducted fans. And aircraft that fly high and transonic tend to stay there as long as possible outside of ascent and descent, so turbofans are a better option than undusted fans.

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Hattix@reddit

Likewise, aircraft that need to fly low and slow tend to only fly low and slow, so turboprops are a better option than unducted fans. And aircraft that fly high and transonic tend to stay there as long as possible outside of ascent and descent, so turbofans are a better option than undusted fans.

This is kind of putting the cart before the horse, I'd say. Aircraft which fly high and transonic do so because that's where they get the best specific fuel consumption, because that's where their engines deliver that. They don't fly there because they want to, they fly there because they have to.

Similar with turboprops, they don't lurk in the FL150 to FL250 heights because they want to, they do it because they have to.

An unducted fan engine would open up FL250-FL350 as an efficient regional/continental altitude, get better fuel economy per kilogram-kilometer (that's an interesting unit) doing it than either a turboprop or a turbofan would, ultimately being the cheapest way to get from where you are to where you want to be. Airlines love that. It's what they optimise for.

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redmercuryvendor@reddit

An unducted fan engine would open up FL250-FL350 as an efficient regional/continental altitude, get better fuel economy per kilogram-kilometer (that's an interesting unit) doing it than either a turboprop or a turbofan would

But do they get better fuel economy than a turboprop or turbofan would in their own flight regimes of optimum efficiency? Because that's what matters: if an unducted fan is more efficient than a turofan at the same medium altitude and speed, but less efficient than a turbofan at high altitude and transonic (i.e. unducted fan and turbofan both in their own regimes of optimum efficiency), then the turbofan will be chosen every time because it is both cheaper in terms of fuel, and cheaper in terms of overall operating cost (e.g. if you can fly 20% faster, you can fly 20% more paying routes with the same sized airfleet in the same timeframe and thus generate 20% more revenue for the same operating period).

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HardlyAnyGravitas@reddit

Here's a good video if anyone wants to learn more:

https://youtu.be/4ek7vsyV1Eg?si=sGvWL_swmEPGqaUq

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SuperMcG@reddit

This is the latest attempt, a lot on youtube about them. I believe they claim the noise level is down as well. CFM International RISE - Wikipedia

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DarthBrooks69420@reddit

Great promise in beating out the Concorde as the most obnoxiously loud passenger jet ever made.

With the engines mounted at the back it might be possible to reduce interior noise by a bit, but those propellers are rotating at mach1+ velocities and making miniature sonic booms every revolution. Its like a 90s Honda Civic or a sports bike, but gunshot loud.

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DeltaV-Mzero@reddit

And they’ve been showing that promise for the last 35 years! Lol

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olly1200@reddit (OP)

I think your correct , hopefully it happens one day as I quite like the idea of it

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Disastrous-Plant-418@reddit

It seems to me that that design would also lend itself well to hybridization at first, then full electric as battery or fuel cell technology advances. I could see a jet fuel-electric combination for the extra thrust at takeoff, and pure electric for cruise

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andrewrbat@reddit

One untimely fan blade release, and no more propulsion…. Not a great idea lol

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SloCalLocal@reddit

A late friend of mine worked on propfan-like cruise missiles for the US Navy back in the 80s and early 90s. The test articles were indeed rather loud (audibly).

Fun facts: if you look closely at some test articles that are sitting in museums, you'll see once-classified detail. Like the fact that on some of them the prop pitch was variable, and more interestingly the props on at least one test article did not counterrotate. There was a fair bit of effort going on into shaping the aerodynamic wake of the missile as that can drive observables once all the other signatures are low enough. Also note that not all exposed propellers will result in a massive RCS spike (materials matter). Interesting stuff!

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zekromNLR@reddit

I assume a non-counterrotating single prop isn't a big issue for a missile as it is boosted to high speed with a rocket so it never has to deal with having too low airspeed over the fins to counteract the torque from it?

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Only_Building6645@reddit

who is the manufacter of this aircraft?

does this aircraft have a name?

or this is a hoax?

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xrelaht@reddit

ecoJet by easyJet. There was no manufacturer selected.

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Special_Conflict5464@reddit

Hard jet.

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Luton_Enjoyer@reddit

I remember seeing a CG image of this plane on the front page of a magazine as a kid and feeling so hopeful for the future.

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Erikrtheread@reddit

Definitely looks like a Pop Sci special.

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olly1200@reddit (OP)

Yeah would of been cool if it did Couldn’t imagine there is many of these models about 🤷‍♂️

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antarcticgecko@reddit

Why the slight forward sweep and not rear swept rings I wonder?

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Denbt_Nationale@reddit

I think the engines at the back cause it to be rear heavy so they need the centre of lift further back. If the wings were swept backwards they’d need to be placed further back and there would be a risk of striking the wingtips on the ground during landing.

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Anchor-shark@reddit

Forward swept wings can be a lot more efficient aerodynamically, but they are hard to build due to the twisting moments. Basically they can’t be metal, have to be composite. So this could offer advantages and be more fuel efficient. Or it just looks cool for a concept ¯_(ツ)_/¯

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Voodoo1970@reddit

it just looks cool for a concept

This is the most likely reason

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Crimson__Fox@reddit

I bet the interior would look like this:

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NoDoze-@reddit

OMG that looks SO uncomfortable, especially for my long legs.

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flopjul@reddit

I prefer the KLM(and TU Delft) Flying V prototype

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Anindefensiblefart@reddit

The wings blended into the background when I first looked at this. I would have been pretty surprised if that could fly.

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SolidPrysm@reddit

I'm not an aerospace engineer but those engines look both extremely dangerous and extremely fragile

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F10XDE@reddit

Not too different from the last time you posted it

https://www.reddit.com/r/WeirdWings/s/mn8NzXI8zF

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olly1200@reddit (OP)

Correct , but I want to see people’s opinions

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qzy123@reddit

What’s with the candy bar wings?

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Loan-Pickle@reddit

More of an easyFan.com.

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yamthirdnow@reddit

Slow. Power in, nose down. Will need 10 fuel pumps.

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2andaHalfBlackClouds@reddit

Is that model really set up on a chopping block?

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olly1200@reddit (OP)

Came from the easyjet head quarters in Luton , my poor grandad bless him was really well known up there and had plenty of mates that worked in offices and on the ground got passed this model and he had it ever since then he passed and I got it

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Jessie_C_2646@reddit

Not a million miles away from the DC-8 Skybus concept.

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AskYourDoctor@reddit

A big part of me wants this sort of thing to happen, just because finally, the first commercial plane that actually looks different since the Boeing 707

(Well, not counting the Concorde I guess...)