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Airbus patents Mach 4.5 plane

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Airbus patents Mach 4.5 plane

Old 7th Aug 2015, 23:39
  #21 (permalink)  
 
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Nevermind the sonic boom... Would two turbojets pass the airport noise restrictions?

And would turbojets this small even get this thing off the ground?
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Old 8th Aug 2015, 22:53
  #22 (permalink)  
 
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Note from the patent that cruising altitude is 30,000 m to 35,000 m

Within the text of the patent, a military version is envisioned
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Old 9th Aug 2015, 05:16
  #23 (permalink)  
 
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Nevermind the sonic boom... Would two turbojets pass the airport noise restrictions? And would turbojets this small even get this thing off the ground
Taking your points in reverse order - proposed takeoff (per the patent) is with both turbojet and rocket power. But that obviously makes your first point more relevant - what kind of noise does two turbojets PLUS a high-thrust rocket make? Probably not Space-Shuttle volume - but could be similar.

Probably depends on the weight that has to be moved. This thing has a payload estimate of just 2-3 tonnes (20 pax), but a BIG tank of slurried H2.

Some other tech points that have been missed:

1) Emissions - everything is H2/O2-powered, so zero carbon or sulphur emissions. Just water, and some loose H2 (which is what 99.99999% of the universe is made of anyway.) Nitrides or ammonia - probably some from the turbojets when burning hydrogen with atmosphere (a non-chemist's guess), but that is only in the subsonic phases. On-board electric is either batteries or H2O2 fuel cells.

2) At Mach 4.5 horizontal cruise, the shock cone is twice as narrow (11-15°) as with, say, Concorde (30°). So it doesn't sweep the ground until twice as far away (even without the doubling of cruise altitude). If it's quieter than, say, the shunting of railroad freight cars I hear all the time (from 2 miles away they still sound like explosions in a boiler-factory), and which are apparently legal, and far more common....?

Economics? Hey, the 1% of the 1% probably doesn't care if it costs $200,000. The real question is how often, in the era of smartphones and skype and such, they really need to make a transglobal round-trip in one day (and how comfortable they are on rollercoasters!)?

I won't get into the patent "politics" - except to say I don't disagree with most of what already has been said.
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Old 9th Aug 2015, 11:06
  #24 (permalink)  
 
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Mach 3.5 at FL800 is about 250KIAS, not so bad.
But temperature raise is definitely a factor.
But new generation aircrafts had been always build after new type of engines. This model lacks a idea for engines. The so called CDE would be a plausible idea. The idea is constantly to have small explosions which producing a substantial higher impulse than rocket motors. Possible would be a marriage of ramjet with a CDE motor. If the small cannons are in positions to bring the airstream into rotation, it could be a highly efficient motor.

Aerodynamically all of this drafts are utterly weak, producing high drag, low lift in certain situations, low maneuverability. They showing clearly that since several years no inventors are in Aerodynamik.
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Old 9th Aug 2015, 20:36
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All this is drifting into the area of Aurora:

'Aurora' spy plane that travels SIX TIMES the speed of sound blamed for mysterious booms | Daily Mail Online
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Old 10th Aug 2015, 20:51
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with current emissions restrictions and other regulatory bollocks we won't see anything supersonic for another half a century at least
If it runs on hydrogen as indicated, the only emissions will be water vapor, which should be politically correct as it contains no carbon.

On the other hand dumping tons of water vapor in the atmosphere at 100,000 feet may be worse than dumping carbon at that altitude. H2O has more of a greenhouse effect than CO2.
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Old 11th Aug 2015, 14:52
  #27 (permalink)  
 
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They are going to be using serious quantities of hydrogen. It'll be interesting to see if they produce patents on new methods of its production, over and above Boyce, Keely, Lawton et alia. That could really benefit us all.
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Old 11th Aug 2015, 15:23
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Maybe one day Airbus will patent this,

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Old 11th Aug 2015, 16:20
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nice angle
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Old 13th Aug 2015, 19:48
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With a bit of tweaking using current technology in a proven concept of 50 years ago this could be reality sooner than the Airbus patent. . . .

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Old 13th Aug 2015, 19:55
  #31 (permalink)  
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Originally Posted by Green-dot View Post
With a bit of tweaking using current technology in a proven concept of 50 years ago this could be reality sooner than the Airbus patent. . . .
Fuel carrying capacity?
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Old 13th Aug 2015, 21:31
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Fuel carrying capacity?
over 47.000 US Gallons / approx. 320.000 lbs (prototype configuration only) in 11 tanks.
Demonstrated cruise speed M 3.1 at 70.000 ft.
Range was never fully explored.
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Old 14th Aug 2015, 15:13
  #33 (permalink)  
 
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Fuel carrying capacity?

over 47.000 US Gallons / approx. 320.000 lbs (prototype configuration only) in 11 tanks.
Problem is; looking at the artists conception in post 32, passenger cabin windows are shown extending back to where the fuselage tank is located. You can either have useful range or carry cargo/passengers. The only space left is actually in the weapons bay, located between the engine inlet ducts.

The original design depended on the use of a a toxic fuel (zip fuel). But when that was dropped, most of the remaining fuselage space was converted to fuel tankage to carry JP-6.
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Old 14th Aug 2015, 16:51
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Right. Remember that part of the design mission is zero carbon emissions.

That means LH2 (liquid hydrogen) fuel. Which is only liquid at extremely low temperatures and/or extremely high pressures (something like 500 bars/atmospheres or 50 million pascals). It ain't kerosene (or even Zip fuel, which is just kerosene with boranes added).

So you need a substantial pressure vessel for the fuel. You can't just tuck it into nooks and crannies throughout the aircraft (and certainly not the leaky wings of the SR-71 ).

H2 is not very dense, even in liquid form (~70 Kg per cubic meter) - but it is bulky. Thus the fat fuselage that is 50% pressure tank.

The Airbus design makes a virtue out of necessity by putting the delta wing on top, and giving the fuselage around the tank a wedge shape to promote compression lift below the wing (which the XB-70 also did, with the aft fuselage).

Think of this Airbus proposal as the Space Shuttle - with the orbiter cabin placed on the nose of the fuel tank instead of on top, and within one aerodynamic skin. Or as a fatter XB-70, with the "crank" in the fuselage/engine box straightened out.

The other design goal is minimum sonic impact on populated areas. Neither the SR-71 or the XB-70 could accelerate through Mach 1 (and on up to Mach 4.5) while in a vertical climb (70°+ pitch angle) at or above 45,000 feet. Not even close.

Concorde could reach Mach 2 only with a long, slow climb of about 20 minutes between ~27,000 feet and 51,000 feet, and a pitch of 4-5 degrees. The SR-71 had to level off at 33,000 feet and enter a descent (the "dipsy-doodle") to punch through Mach 1, followed by a Concorde-like climb/accleration at a constant 450 KEAS.
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Old 14th Aug 2015, 18:45
  #35 (permalink)  
 
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Problem is; looking at the artists conception in post 32, passenger cabin windows are shown extending back to where the fuselage tank is located.
That is correct for the original XB-70 design. But taking this design / concept into the 21st century using current state-of-the-art technology and scaling up the dimensions of the aircraft (within the current 80 by 80 meter airport limits) and enlarging the fuselage both in diameter and length, extending the passenger compartment all the way to the tail section would make it feasible. Fuel would be stored in the larger wing tanks, including the folding wing tips (which had no fuel tanks in the XB-70), and perhaps in the compartment that was originally designed as weapons bay. The original six YJ-93 turbo jets can be replaced by, say, four variable cycle engines or super cruise designs. Type of fuel is open for discussion.

The other design goal is minimum sonic impact on populated areas. Neither the SR-71 or the XB-70 could accelerate through Mach 1 (and on up to Mach 4.5) while in a vertical climb (70°+ pitch angle) at or above 45,000 feet. Not even close.

Concorde could reach Mach 2 only with a long, slow climb of about 20 minutes between ~27,000 feet and 51,000 feet, and a pitch of 4-5 degrees. The SR-71 had to level off at 33,000 feet and enter a descent (the "dipsy-doodle") to punch through Mach 1, followed by a Concorde-like climb/accleration at a constant 450 KEAS.
The XB-70 accelerated with wingtips lowered to mid-down position through the transonic region at 32.000 ft to M 1.5. Then the wingtips were lowered to their full-down position. M 1.5 was maintained to about 50.000 ft, and then varying rates of acceleration were applied until M 3.0 was reached at 70.000 ft. The best recorded time to M 3.0 was 25 minutes from moment of rotation at take-off.

Last edited by Green-dot; 14th Aug 2015 at 19:10.
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Old 18th Aug 2015, 12:45
  #36 (permalink)  
 
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From the original article -

Airbus has filed other unusual aircraft patents in the past.
For example, last summer, it filed a patent tobicycle-style seats on planes that would make it possible to cram more passengers in the same amount of space. And last fall, it patented an aircraft cabin shaped like a giant flying saucer.
Seats like those on treadlies? No doubt airbus will design 'em a la St Pauls Cathedral (no feckin ball room)...

And Airbus would be wise in following Boeing's tried 'n trusted 'That Looks About Right" rule...



Mr Anderson did!
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Old 18th Aug 2015, 16:44
  #37 (permalink)  
 
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That article says:

"Low-cost airlines already cram as many passengers as possible onto their planes, but as anyone who has recently flown economy class can attest, traditional seats can’t get much smaller".

Has Airbus noticed that much of their public seems to be fed on a diet of greaseburgers, taken orally (and possibly in suppository form). This must be another patent straight down the drain.
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Old 18th Aug 2015, 18:40
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Originally Posted by KenV View Post
If it runs on hydrogen as indicated, the only emissions will be water vapor, which should be politically correct as it contains no carbon.
If you ignore the fact that most current hydrogen production comes from natural gas.

The SR71 was originally going to be hydrogen-powered, but I forget exactly why. They dumped that idea because they just couldn't make it work; amongst other things, it would have been a much larger vehicle, just to support the tanks required for the low-density fuel.
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Old 18th Aug 2015, 22:53
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Call me a cynic but there's more chance that Pan Am will grace the skies again than any of this lot of XB70 derivatives or Airbus concepts.
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Old 19th Aug 2015, 11:05
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And when Pan Am does grace the skies again, so will their pioneering spirit of introducing many firsts in their rich history. With someone having the innovative drive of Juan Trippe at the helm they would likely be the first to introduce supersonic (or even hyper sonic) service when its viability one day is proven.

With respect to the XB-70: its impact on aviation has far outstripped her recognition. The aircraft is often a hazy memory, yet the technology it pioneered would dictate aerospace manufacturing for decades after its last flight. The integrated aerodynamic package this aircraft represented would remind designers that shape can best brute force when it comes to speed and performance. Most who even remember the XB-70, recall images of an expensive, cranky, and problematic design.

Until you look at the logs of the second and improved prototype, the confidence that had been developed doesn't come through. One has to remember that the chief test pilot was going to leave the program, signalling that from an engineering standpoint the aircraft had accomplished the goals set for it.

From a pilot's judgement it was an easy airplane to fly, considering that due to budget restraints in this research program the airplane was flown without an autopilot and was equipped with "off-the-shelf" flight deck instrumentation.

Last edited by Green-dot; 19th Aug 2015 at 18:41.
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