zeke wrote:

No way that wing will do M0.9 without sweep

Wing is seemingly inspired by U-2, which was flying on 0.75 range. It had a relatively high L/D=24, which these guys say can be increased to almost 40, low wing loading of 200 kg/m2, and flew as high as 70 k feet (50k listed for triwing)
An instant problem is how to handle emergency descent among other issues.

zeke wrote:

No way that wing will do M0.9 without sweep

Definitely a good point. At those airs peeds, the air over the tops of the wings going supersonic, the turbulence and issues would make the next two wing sets just useless, and the entire thing unstable before they even get close to M0.9

kalvado wrote:

zeke wrote:

No way that wing will do M0.9 without sweep

Wing is seemingly inspired by U-2, which was flying on 0.75 range. It had a relatively high L/D=24, which these guys say can be increased to almost 40, low wing loading of 200 kg/m2, and flew as high as 70 k feet (50k listed for triwing)
An instant problem is how to handle emergency descent among other issues.

Didn’t think the cruise speed was that high, with the XF-11, U2, and M-55 they all had a high aspect ratio wings with a taper ratio, that taper ratio gave a leading edge sweep angle.

GalaxyFlyer wrote:

Engineers fight over 2% improvements, no way did they miss a 70% improvement in fuel burns.

Only because in the business of commercial airlines there's no corporate appetite for novel risk-taking.

Why wasn't the A380 a BWB? Why did the Sonic Cruiser disappear into oblivion? Because neither manufacturer had the confidence to make the leap.

One thing no one commented on - they wanted to abandon the barrels and build a monocoque fuselage. I can see how the lack of joints will save weight, but I would also assume the production cost for this will be high.
For the triple wing pairs, won't the airflow over one wing disturb the flow over the next wing? What will be the drag/lift ratio compared to a single, bigger wing? Three weaker wingboxes compared to one bigger?
New ideas are interesting, some of them changes the game completely while others will remain engineering fantasies. When will you go on the Hyperloop powered by a fusion power nuclear plant?
Personally I'll wait for the return of the Zeppelins for heavy freight..

DocLightning wrote:

Two features will be especially excellent for aerodynamic efficiency:

1) Having the two trailing wings in the wake of the first.
2) Three times the wingtips.

From a structural standpoint, all the extra reinforcement in the fueslage to hold up the fuel tanks in the overhead space will most certainly lighten the airframe and also having the fuel tanks up there will present an optimal safety situation that the FAA will most certainly appreciate.

Finally, single-engine designs are a cutting-edge solution for optimum efficiency and safety. You don't even have to bother with a Vr!

Good luck certifying one engine. There are in flight shut downs.

The fuel tanks will be an issue. Firewalls exist so that when a tank is punctured the passengers are safe.

I am not seeing the 70% claimed drop in fuel burn. I look at each feature and estimate the fuel savings and in no way do I get anything more than 25%. This would be like comparing my undergrad design to real world. I missed 25% of the empty weight as I didn't fully account for wiring, fire suppression, and how heavy joints in aircraft design are.

Everyone wants joint free CFRP. There is massive research on continuously woven structure going on today. But that is to cut 5% of weight.

Fuel is in wings as that reduces moment at the wing root and thus saves weight.

I do not see features to take hitting a pot hole on a taxiway. Also a tail engine means structure to carry the thrust to the drag (wings and fusalage). While simple wings are fun to design, a triple wing has more structure per wing area.

A triple wing also has a stall in certain angles of attack. The whole reason horizontal stabilizers are built for downforce is that during rotation a rear wing will stall. This is a non-trivial concern.

I normally love new concepts. This is a school project missing fundamental design features. BWB evacuation is far easier than fuel over passengers to certify.

1st: a 2nd engine.
2nd. features to prevent wing stall during moderate angles of atrack.
3rd: fuel fire safety
4th, landing gear robustness for pot holes
5th the structure isn't built for the wobble of a hard landing.
6th everyone likes V-tails untill planning test certification (stall margins, engine out takeoff). Then they don't

I want a BWB with lifting body and without the drag of the vertical stabilizer. Twin stabilizers are sexy and draggy.

Lightsaber
Lightsaber

lightsaber wrote:

[
Good luck certifying one engine. There are in flight shut downs.

That pot I was stirring was a pot full of sarcasm.

ELBOB wrote:

Why did the Sonic Cruiser disappear into oblivion?

Because it burned something like 1.5-2x the fuel per ASM while offering a 10% speed improvement.

Boeing757100 wrote:

How expensive would maintenance be on this design again?

Very expensive from all the ground damage I imagine. Three wings, with split winglets. I guess ground safety guys will be busy too.

Very amusing thread, some really funny stuff. Thanks!

Just maybe it would work with a variable wing sweep? It would be neat to see those wings move back when the plane got up to cruising speed.

DocLightning wrote:

lightsaber wrote:

[
Good luck certifying one engine. There are in flight shut downs.

That pot I was stirring was a pot full of sarcasm.

It looks like no one has read the original article properly.

http://robbreport.com/motors/aviation/se-aeronautic-se200-tri-wing-jumbo-jet-concept-1234613101/

Quote: The tri-wing design, with a double tail fin and two engines mounted to the rear..,

The the a/c has two engines, one in the fuselage and one above. The air intake duct of the internal engine can be seen clearly on the renderings.

So at least the "one engine problem" is none.

Heinkel wrote:

DocLightning wrote:

lightsaber wrote:

[
Good luck certifying one engine. There are in flight shut downs.

That pot I was stirring was a pot full of sarcasm.

It looks like no one has read the original article properly.

http://robbreport.com/motors/aviation/se-aeronautic-se200-tri-wing-jumbo-jet-concept-1234613101/

Quote: The tri-wing design, with a double tail fin and two engines mounted to the rear..,

The the a/c has two engines, one in the fuselage and one above. The air intake duct of the internal engine can be seen clearly on the renderings.

So at least the "one engine problem" is none.

The rendering is pretty clear that it’s a stacked 2x engine design. Which presents all sorts of issues.

And a video for our simple flying fanboys here:
https://youtu.be/5_m0IgEshYc

Good news:
While fuel consumption goes down 70%, CO2 emissions even go down 80%.

The comments under that YouTube video are along the lines of what is posted here. You might scan them if you are interested. I don’t think one was positive.

ELBOB wrote:

GalaxyFlyer wrote:

Engineers fight over 2% improvements, no way did they miss a 70% improvement in fuel burns.

Only because in the business of commercial airlines there's no corporate appetite for novel risk-taking.

Why wasn't the A380 a BWB? Why did the Sonic Cruiser disappear into oblivion? Because neither manufacturer had the confidence to make the leap.

For 70% improvement in fuel burn, they certainly will take risk.

Why did the Sonic-Cruiser disappear? Because no airline was willing to pay the fuel cost of that little extra speed; instead, they asked for better efficiency and the 787 was born.

Sokes wrote:

Good news:
While fuel consumption goes down 70%, CO2 emissions even go down 80%.

How can that be? CO2 emissions are a direct link to the quantity of fuel burned; so, if the fuel consumption goes down by 70%, the CO2 rejected goes down by 70%,

MrBretz wrote:

The comments under that YouTube video are along the lines of what is posted here. You might scan them if you are interested. I don’t think one was positive.

The video was posted by Simple Flying (itself a not-so-reliable source) on April 2nd; did they take a April Fool's joke and run with it? Sure sounds like it.

In a related way, sort of, here is a possible competitor to the SE200. And they already have a prototype you can see in the video. And it’s not a simulation. It a real prototype. Maybe the guys can license it to Boeing and it can be their next new aircraft.

https://gizmodo.com/the-russians-supers ... 1846354347

SE Aeronautic’s corporate address is a vacant lot next to a wedding hall. The wedding hall and SE Aeronautic have the same owners/family running them. This company appears to be a fantasy or investment scam.

WayexTDI wrote:

Sokes wrote:

Good news:
While fuel consumption goes down 70%, CO2 emissions even go down 80%.

How can that be? CO2 emissions are a direct link to the quantity of fuel burned; so, if the fuel consumption goes down by 70%, the CO2 rejected goes down by 70%,

That's the joke. I believe that full plane is a joke.

To put it in historical context:
The book "Extraordinary popular delusions and the madness of crowds" from 1841 gives examples of bubble investments and superstitions.
https://en.wikipedia.org/wiki/Extraordi ... _of_Crowds

It's a bit lengthy to read and I skipped some chapters, but at times I was laughing so strong as rarely before. So I highly recommend that book.
That book gives an example how somebody at the height of a bubble collected money from investors for a project whose purpose will be revealed in due time.
Somehow that plane reminds me of that book. Well, we are in a bubble. I guess somebody will fund it.

All current airliners are all low winged, twin engined, conventional tailed monoplanes with engines under the wings for a reason. That is structurally and aerodynamically the most efficient layout, at lest for a tube with wings. A BWB would undoubtedly be more efficient, but that is the only concept of which I am aware that offers any substantial gain in efficiency. And that has problems that so far have eluded solutions that would make it a commercially viable concept. Engineers at all of the manufacturers have been playing around with exotic concepts for a century, and if there was a layout that offered substantial efficiency gains with acceptable stability I am sure someone would have stumbled upon it by now. I doubt very much that this is it.

They could of course not show everything they intend to do on any of the renderings to stop competitors pinching their ideas, you never know. Although I wouldn't be holding my breath waiting for this to fly, it would be some sight if it does. Could thinner lighter wings mean you could put smaller less powerful engines on them but still have the same power with more fuel efficiency?

SEPilot wrote:

All current airliners are all low winged, twin engined, conventional tailed monoplanes with engines under the wings for a reason. That is structurally and aerodynamically the most efficient layout, at lest for a tube with wings. A BWB would undoubtedly be more efficient, but that is the only concept of which I am aware that offers any substantial gain in efficiency. And that has problems that so far have eluded solutions that would make it a commercially viable concept. Engineers at all of the manufacturers have been playing around with exotic concepts for a century, and if there was a layout that offered substantial efficiency gains with acceptable stability I am sure someone would have stumbled upon it by now. I doubt very much that this is it.

They probably said something similar when all the aircraft flying around where bi or tri-planes. New technology makes new things possible...

jomur wrote:

SEPilot wrote:

All current airliners are all low winged, twin engined, conventional tailed monoplanes with engines under the wings for a reason. That is structurally and aerodynamically the most efficient layout, at lest for a tube with wings. A BWB would undoubtedly be more efficient, but that is the only concept of which I am aware that offers any substantial gain in efficiency. And that has problems that so far have eluded solutions that would make it a commercially viable concept. Engineers at all of the manufacturers have been playing around with exotic concepts for a century, and if there was a layout that offered substantial efficiency gains with acceptable stability I am sure someone would have stumbled upon it by now. I doubt very much that this is it.

They probably said something similar when all the aircraft flying around where bi or tri-planes. New technology makes new things possible...

It is only recently that all new airliners follow the same design. New technology does not change basic principles of aerodynamics. In prior years designers tried various configurations, but experience and better understanding, plus greater emphasis on efficiency, led all designers to the same basic pattern. The 737, for example, was originally going to be a two engined version of the 727 like the DC-9, but Joe Sutter showed that by putting the engines under the wings he could add two rows of seats for the same weight. And nobody has put rear mounted pairs of engines on an airliner since. The DC-10 and L-1011 had single rear mounted engines because they had to be on centerline, but the pairs were under the wings. And note that both of them have a low horizontal stabilizer; no more T-tails. Engines under the wings are most efficient because they put their weight directly on the wing, reducing bending moment at the wing-fuselage joint and hence requiring less structural strength. The same goes for carrying the fuel in the wings. T-tails require a much stronger (and hence heavier) vertical stabilizer. A high wing would be more aerodynamically efficient (little or no dihedral required) but it would require much longer and heavier landing gear, canceling out any gain. Canards instead of rear mounted horizontal stabilizers are more efficient because both the canard and the wing are lifting surfaces (the conventional horizontal stabilizer produces downforce), but lead to a much narrower safe CG range, and hence are impractical. New technology never will change any of that.

SEPilot wrote:

jomur wrote:

SEPilot wrote:

All current airliners are all low winged, twin engined, conventional tailed monoplanes with engines under the wings for a reason. That is structurally and aerodynamically the most efficient layout, at lest for a tube with wings. A BWB would undoubtedly be more efficient, but that is the only concept of which I am aware that offers any substantial gain in efficiency. And that has problems that so far have eluded solutions that would make it a commercially viable concept. Engineers at all of the manufacturers have been playing around with exotic concepts for a century, and if there was a layout that offered substantial efficiency gains with acceptable stability I am sure someone would have stumbled upon it by now. I doubt very much that this is it.

They probably said something similar when all the aircraft flying around where bi or tri-planes. New technology makes new things possible...

It is only recently that all new airliners follow the same design. New technology does not change basic principles of aerodynamics. In prior years designers tried various configurations, but experience and better understanding, plus greater emphasis on efficiency, led all designers to the same basic pattern. The 737, for example, was originally going to be a two engined version of the 727 like the DC-9, but Joe Sutter showed that by putting the engines under the wings he could add two rows of seats for the same weight. And nobody has put rear mounted pairs of engines on an airliner since. The DC-10 and L-1011 had single rear mounted engines because they had to be on centerline, but the pairs were under the wings. And note that both of them have a low horizontal stabilizer; no more T-tails. Engines under the wings are most efficient because they put their weight directly on the wing, reducing bending moment at the wing-fuselage joint and hence requiring less structural strength. The same goes for carrying the fuel in the wings. T-tails require a much stronger (and hence heavier) vertical stabilizer. A high wing would be more aerodynamically efficient (little or no dihedral required) but it would require much longer and heavier landing gear, canceling out any gain. Canards instead of rear mounted horizontal stabilizers are more efficient because both the canard and the wing are lifting surfaces (the conventional horizontal stabilizer produces downforce), but lead to a much narrower safe CG range, and hence are impractical. New technology never will change any of that.

Thanks for the Cliff's Notes, SEPilot. That makes a lot of sense. To boot, wing-mounted engines also offer better mx access (I'm reminded of "the patio" on the -10).

jomur wrote:

SEPilot wrote:

All current airliners are all low winged, twin engined, conventional tailed monoplanes with engines under the wings for a reason. That is structurally and aerodynamically the most efficient layout, at lest for a tube with wings. A BWB would undoubtedly be more efficient, but that is the only concept of which I am aware that offers any substantial gain in efficiency. And that has problems that so far have eluded solutions that would make it a commercially viable concept. Engineers at all of the manufacturers have been playing around with exotic concepts for a century, and if there was a layout that offered substantial efficiency gains with acceptable stability I am sure someone would have stumbled upon it by now. I doubt very much that this is it.

They probably said something similar when all the aircraft flying around where bi or tri-planes. New technology makes new things possible...

Except monoplanes were flying only a few years after the first powered flight (Blériot VII in 1907).

As for BWBs they look cool but more efficient is something that needs to be proven. It depends entirely on the ability to build a BWB with the right weight.

I especially like the "fuel bladder" in the crown of the plane.

Aesma wrote:

jomur wrote:

SEPilot wrote:

All current airliners are all low winged, twin engined, conventional tailed monoplanes with engines under the wings for a reason. That is structurally and aerodynamically the most efficient layout, at lest for a tube with wings. A BWB would undoubtedly be more efficient, but that is the only concept of which I am aware that offers any substantial gain in efficiency. And that has problems that so far have eluded solutions that would make it a commercially viable concept. Engineers at all of the manufacturers have been playing around with exotic concepts for a century, and if there was a layout that offered substantial efficiency gains with acceptable stability I am sure someone would have stumbled upon it by now. I doubt very much that this is it.

They probably said something similar when all the aircraft flying around where bi or tri-planes. New technology makes new things possible...

Except monoplanes were flying only a few years after the first powered flight (Blériot VII in 1907).

As for BWBs they look cool but more efficient is something that needs to be proven. It depends entirely on the ability to build a BWB with the right weight.

I work for a major aerospace company that again and again has proven BWBs have more efficiency. There is a reason so many smaller military designs (e.g., UCAS) adopt the configuration; once you have good control logic, the design makes sense.

This tri-wing has too much surface area of wing to take seriously. There are certain fundamental design ideas and one is to eliminate the rudder as that is a major source of not required drag. A good fuel system eliminates the need for the horizontal and vertical stabilizers.

If there was a design that could reduce fuel burn 70%, the industry would be all over it. After a 15% advantage, the prior generation stops selling.

I wish I could share all the prototype research on BWBs from Airbus, Boeing, Northrop, and Lockheed, but the good information is under NDA. Raytheon technologies is more into lifting bodies (A380 is a partial lifting body).

Lightsaber