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lehpron
Topic Author
Posts: 6846
Joined: Tue Jul 10, 2001 3:42 am

Is Sonic Cruiser's Shape Necessary?

Wed Jul 11, 2001 3:11 am

I recall from a trip my family took to India in the summer of 1994 where we had taken a 747-400 across the Pacific, non-stop from Los Angeles to Seoul, Korea. During the flight somewhere over San Francisco, we had maintained a speed of 1111 kilometers-per-hour for a few minutes. I remembered this partly because it was looping on a map on the movie screen in front of the middle seats and I have never seen four number one's close together.

I didn't calculate it until I went home; it seemed as though we were going almost 700 mph! Boeing's website and countless others state that the jumbo jet cruises at 580-600mph, I know all airplanes are capable of short bursts of speed, but we were going faster than your proposed concept.

Air Force One is a beefed-up 747. On military websites, it states an official 701-mph cruise speed. Why is there a need for new shape? As you approach Mach 1, drag increases, and to overcome drag you need thrust; lots of it!

I'll bet if the GE90 engines from two 777's were installed on a 747 then there will be real compete with the Airbus A380 in term of a high speed and capacity. Boeing can tinker around with it; have their cake and eat it too, so to speak.

lehpron (college junior)
The meaning of life is curiosity; we were put on this planet to explore opportunities.
 
KROC
Posts: 18919
Joined: Mon May 08, 2000 11:19 am

RE: Is Sonic Cruiser's Shape Necessary?

Wed Jul 11, 2001 3:36 am

I believe teh 580-600MPH is ground speed for the Aircraft. When the Airplane is in the air, its air speed can be much faster due to factors like wind speed and such. The Jet Stream in a big factor in this. I may have this all hosed up, but hopefully I helped.

MC
 
Ralgha
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Joined: Tue Nov 09, 1999 6:20 pm

RE: Is Sonic Cruiser's Shape Necessary?

Wed Jul 11, 2001 4:30 am

The airplane's airspeed is what is shown in the specs for the airplane. What you see on the map in the cabin is the groundspeed, which can be much higher or lower depending on wind.

 Big thumbs up
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Jean Leloup
Posts: 2004
Joined: Fri Apr 06, 2001 10:46 am

RE: Is Sonic Cruiser's Shape Necessary?

Wed Jul 11, 2001 7:49 am

True, that was groundspeed. AF One achieves it's speed by being very uneconomical with it's fuel... the efficiency i guess, is why the SC demands a new shape. Putting 4 GE90's and extending the U/D on the 747 won't make it compete against the A380, it would probably just tear the wings right off! :-9
Jean Leloup - original a.net moderator (2001-2005) and still recovering!
 
charlieduke
Posts: 36
Joined: Fri May 18, 2001 12:28 am

RE: Is Sonic Cruiser's Shape Necessary?

Wed Jul 11, 2001 7:59 am

Things that make you go hmmmm...
Why would Boeing design an aircraft that appears to deal with supersonic issues such as transitional boundary layers, laminar flow and sonic footprint? hmmmmmm
 
lehpron
Topic Author
Posts: 6846
Joined: Tue Jul 10, 2001 3:42 am

American Industry Has Become Profit Happy

Thu Jul 12, 2001 10:05 am

In the past, Boeing, for example, hasn't thought through some of their previous concepts.

I never knew before that Boeing had a 70% market monopoly ten years ago and it's now down to 60% and dropping because of Airbus. I see Boeing as derivative-profit happy and the last time they bet the company on something it was with the 707 and the 747.

They seemed annoyingly obsessed with going Mach 3 with a swing-wing design in three different configurations, back in the 60's.

Then there was the cancellation of the 747-500/747-600, the HCST, the NASA X-30, X-33, X-34; and their still doing it!

I almost see it as a conservative approach to prove extreme ideas won't work; risk refusal -- it really pisses me off!

Concorde works, technically speaking of course. Why not build another Mach 2 airliner? Why does the HSCT have to be so big? If they were smaller, their shockwaves footprints would be like a fighter plane or cruise missile. This size should only be for hypersonic airliners.

Why have laminar flow to reduce drag? (We lost the record for supersonic car to the Brits cuz we were obsessed with drag)

Why use a turbojet with a noise muffler? At no cost in fuel, we get good noise ratings out of a turbofan. Halleluiah, let's add that muffler, it'll get real quiet now.

Why increase cost to passengers? I honestly think with all the delays and cancellations, nobody is willing to pay more just to go faster. What are they going to complain about?

Less fuel, less engine noise, less sonic boom: inexpensive. This is my goal actually; I think it can be done, what about you?

Lehpron [email protected]
The meaning of life is curiosity; we were put on this planet to explore opportunities.
 
Guest

RE: American Industry Has Become Profit Happy

Thu Jul 12, 2001 10:18 am

In case you didn't notice, delays become a problem for domestic flights only. I don't remember
every being delayed on an international flight, but here, we have little MD80's zipping
by on extremely tight, money-making schedules, and any small weather problem can
cause delays to ripple through very far.

Btw, the last project was 777, designed completely on computers and it cost quite a
bit too. It wasn't a company betting itself, but it was very innovative. As for Airbus, they
live off derivatives too. In fact, if you notice all their airliners look much more similar than do
different Boeing jets. That's nothing bad. Any fool who has worked in any engineering
field will tell you the three R's -- Reuse, Reuse, Reuse. It's common and business sense
too. Any company that wants to make profit reuses as must as it can.
 
XFSUgimpLB41X
Posts: 3961
Joined: Fri Aug 25, 2000 1:18 am

RE: Is Sonic Cruiser's Shape Necessary?

Thu Jul 12, 2001 10:36 am

I say ditch the shape and just make it a big box.. who needs engineers?  Big grin
Chicks dig winglets.
 
GDB
Posts: 13989
Joined: Wed May 23, 2001 6:25 pm

Charlieduke

Fri Jul 13, 2001 2:01 am

Thinking what I am, the M.98 SC is an interim aircraft? The next version could be capable of Mach 1.2-1.6? Need a radical engine probably, not a derivative.
PS, is your user ID named after the Apollo 16 Astronaut?
 
fbwless
Posts: 207
Joined: Tue Feb 08, 2000 2:07 am

RE: Is Sonic Cruiser's Shape Necessary?

Fri Jul 13, 2001 4:05 am

The russians has done tests with a sea-going torpedo that almost has a flat front to create a gas bubble around it. With this in mind, maybe something similar could be done with an airplane. Just a thought ...
 
charlieduke
Posts: 36
Joined: Fri May 18, 2001 12:28 am

GDB

Fri Jul 13, 2001 10:12 am

Yes, I believethe Sonic Cruiser will be supersonic. And no radical new powerplant is required. Take for example the PW F119. It can push the F-22 to m1.58 without afterburner (supercruise). The technology is there already. And "Charlieduke" is just a childhood nickname.
 
tullamarine
Posts: 2643
Joined: Thu Aug 05, 1999 1:14 pm

RE: Is Sonic Cruiser's Shape Necessary?

Fri Jul 13, 2001 11:07 am

Who knows whether the SC shape is firm or merely indicative of what Boeing is currently thinking about. When the first sketches emerged it was hard even to work out the scale of the picture. No doubt Boeing is currently talking to airlines about their needs and from this the true scope of the project will emerge (or die?) and at some point down the track a design frozen.

It is unlikely that SC will be supersonic at this stage. The environmental effects of supersonic aircraft means that their use is limited. One of the main sticking points with Concorde was sonic boom which meant that it was pretty much unable to fly anywhere at supersonic speeds unless it was over water at the time.
717, 721/2, 732/3/4/5/7/8/9, 742/3/4, 752/3, 762/3, 772/E/W, 788/9, 300,310, 319,320/1, 332/3, 359, 388, DC9, DC10, F28, F100, 142,143, E75/90, CR2, D82/3/4, SF3, ATR
 
lehpron
Topic Author
Posts: 6846
Joined: Tue Jul 10, 2001 3:42 am

RE: FBWless

Sat Jul 14, 2001 2:09 am

Hmm, a gas bubble around a sea-going torpedo; that almost sounds like naval stealth...

For it's application to aircraft; maybe the ellimination of a shock wave?

I've heard of such ideas:

1) The nose is bluntly rounded so there is a cusion of air, on the plane, moving faster than the outside air, so the relative speed of sound is less than speed of the aircraft.

Though I think it's quite dangerous,

2) there's idea of purposely increasing the friction temperature so that a thermal heat field around the plane keeps the plane subsonic. From physics and chemistry, sound and air temp are related - as air temp goes up so does the speed of sound in that air medium.

I don't think these ideas are feasible, economical, or even possible for that matter, would have been great for HCST...

lehpron
The meaning of life is curiosity; we were put on this planet to explore opportunities.
 
seagull
Posts: 334
Joined: Sat Jun 30, 2001 5:58 pm

RE: Is Sonic Cruiser's Shape Necessary?

Sat Jul 14, 2001 2:50 am

Sounds like someone is dreaming of things that aren't possible. Whether or not the flow immediately surround the aircraft could be reduced to subsonic, you still are going to have a shock wave induced by the acceleration of the moving mass. No way around that at all, absent creating a worm hole or warping space!

As to the sonic boom, that is largely viewed as protective measure the govt did against Concorde when Boeing decided not to go forward. The sonic boom from a very high flying supersonic aircraft is less intrusive than a regular jet flying at lower altitudes. I miss that sound, hardly hear it anymore.
 
GDB
Posts: 13989
Joined: Wed May 23, 2001 6:25 pm

RE: Is Sonic Cruiser's Shape Necessary?

Sat Jul 14, 2001 4:17 am

Boeing reckon that the right design could reduce the shockwave, no idea by how much, or whether it would work, but $ are being spent by Boeing, Lockheed Martin and NASA to try and find out.
If a supersonic SC is planned, and Boeing have hinted at it, I cannot see adapting a military engine like the F119 would be acceptable for fuel consumption and noise reasons.
As for Concorde's boom, the British side of the programme had decided by the mid 1960's that supersonic flight over heavily populated areas was a non-starter. RAF Lightning fighters had boomed high over London suburbs, the response from the residents was pretty clear!
Concorde's boom would be much worse. I think a similar experiment was carried out over Oaklahoma (SP?) by a USAF B-58, not too different in size and configuration from Concorde. Again, there were strong objections.
For this reason the UK persuaded the French to ditch their medium-range, higher-capacity version of Concorde, and standardise on the UK long-range model.
And finding areas to test Concorde was a trial in itself!
 
Klaus
Posts: 21642
Joined: Wed Jul 11, 2001 7:41 am

Inadvertently Supersonic?

Sat Jul 14, 2001 4:32 am

I´m wondering about a question which would present itself even more urgently with the SC:
Isn´t it possible to inadvertently go supersonic during a normal flight?
Reasons might be related to turbulence, to suddenly encountering a strong headwind or during descent.
The Sonic Cruiser might have an advantage here, but wouldn´t it still be dangerous?

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