Posts about: "Intakes" [Posts: 171 Page: 3 of 9]¶

As requested here is the second in the diabolical series of Concorde quizes. If you were never personally involved withe the aircraft you can leave out the really stinky questions if you want. Most answers can be found either in this thread, by looking at the many panel photos around or as usual by asking Mr Google

1) How many Concorde airframes were built?

2) As far as the British constructed aircraft went, name the destinations that were served?. Regular flight numbers only, excludes charters etc.

3) What was the departure time for the ORIGINAL morning LHR-JFK Concorde services? (Not called the BA001 then either).

4) Further to question 3 above, what WERE the original flight numbers for the BA001 and BA003? (The morning and evening LHR-JFK services?).

Humble SLF here, hope it is ok to have a stab at the questions, mods please feel free to delete if necessary.

1) How many Concorde airframes were built?

22, 20 that flew and 2 test frames

2) As far as the British constructed aircraft went, name the destinations that were served?. Regular flight numbers only, excludes charters etc.

New York, Washington, Miami, Barbados, Toronto, Bahrain and Singapore, no British registered aircraft ever operated to or form Dallas, should not forget BAs most popular destination of all time-London


3) What was the departure time for the ORIGINAL morning LHR-JFK Concorde services? (Not called the BA001 then either).

0930-Local

4) Further to question 3 above, what WERE the original flight numbers for the BA001 and BA003? (The morning and evening LHR-JFK services?).

193 & 195 respectiveley

5) There were no less than FORTY SIX fuel pumps on Concorde. What was the breakdown for these? (Clue; don't forget the scavange pump ).

Pass


6) What was the only development airframe to have a TOTALLY unique shape?

101, G-AXDN


7) This one is particularly aimed at ChristiaanJ. What was the total number of gyros on the aircraft?

pass


8) How many wheel brakes?

8


9) What Mach number was automatic engine variable intake control enabled?

1.3


10) Above each bank of engine instruments were three lights, a blue, a green and an amber. What did they each signify?

Not sure here, best guess -green was part of the take-off moniter -red failure-blue reverse

11) At what airfied were the first BA crew base training details held?

Prestwick, shannon, and one in France


12) What LHR runways did Concorde use for landing and take-off? (Trick question, not as obvious as it might seem).

28L , 28R, 27L, 27R, 9L, 9R 10L 10R, 23

13) What operator had serious plans to operate Concorde from SNN to JFK in the early 1980's?

Fed-ex


14) What development aircraft did not exceed Mach 2 until fifteen months after her maiden flight?

214? G-BFKW

1) How many Concorde airframes were built?

22 total. 2 test, 9 BA, 9 AF, 2 spares (1 BA, 1 AF).

2) As far as the British constructed aircraft went, name the destinations that were served?. Regular flight numbers only, excludes charters etc.

JFK, Dulles Intl., Barbados, Miami, Bahrain, Singapore.

3) What was the departure time for the ORIGINAL morning LHR-JFK Concorde services? (Not called the BA001 then either).

No idea.

4) Further to question 3 above, what WERE the original flight numbers for the BA001 and BA003? (The morning and evening LHR-JFK services?).

No idea.


13 tanks, 2 main pumps each (except tank 11 which had 4 pumps) = 28
Main and aux engine feed pumps (3 per collector, 4 collectors for a total of 12)
Fuel pumps from aux tanks to mains = 4
Fuel dump = 2


BAC 221. Flying test bed for the wing design.






Filton.


27 L/R, 09 R.

OK, I see others have already posted answers.
I've carefully avoided looking at them, but I'll might as well plug in mine now.

My personal problem is that I was involved in the very earliest days, before the aircraft went into service, and then in the last days and afterwards...
So the questions dealing with the in-service period are totally outside my field of experience... all I can do is guess, in case I saw the answers somewhere.

1) How many Concorde airframes were built?
Twenty-two.
Two static-test airframes.
- One at Toulouse, for purely static tests, and tests such as vibration and flutter.
- One at Farnborough, for the long-duration thermal fatigue tests.
(A few bits and pieces of the Farnborough test specimen have survived, and can still be seen at the Brooklands museum).
Two prototypes (001 and 002)
Two pre-production aircraft (01 and 02)
Two production aircraft used for certification, that never entered service (201 - F-WTSB and 202 - G-BBDG)
Fourteen production aircraft, seven that served with British Airways, seven that served with Air France.

2) As far as the British constructed aircraft went, name the destinations that were served?. Regular flight numbers only, excludes charters etc.
Not a clue as to the full list.
- Bahrain, obviously.
- JFK.
- IAD (not sure if that's rated as regular, or only incidental)
- Dallas (with Braniff)
- Barbados (of course, right until the end)
- Sngapore (with Singapore Airlines, and G-BOAD in Singapore Airlines colours on one side)
- Sydney (again no idea if that rated as a regular flight or only a few tries)

3) What was the departure time for the ORIGINAL morning LHR-JFK Concorde services? (Not called the BA001 then either).
Not a clue either. Vague memory of about 10:00 am which gave you a full working day in New York.

4) Further to question 3 above, what WERE the original flight numbers for the BA001 and BA003? (The morning and evening LHR-JFK services?)..
Never flew on them, never had to deal with them.
BA174 comes to mind from the depths of my memory, in that case BA003 would have been BA176?

5) There were no less than FORTY SIX fuel pumps on Concorde. What was the breakdown for these? (Clue; don't forget the scavenge pump )
M2dude, I did AFCS, not the fuel system. I believe you, but without pulling out some diagrams I honestly have NO idea.
I expect each tank had at least two pumps, which gets me up to 26.
Then there were a few emergency pumps for the trim tanks, and I suppose each engine had additional pumps associated with it.
Still nowhere near the 46 I need to find.....

6) What airframe had the only TOTALLY unique shape?
That would have been my old friend, 01 (G-AXDN), first pre-production aircraft, now at Duxford.
It was the first Concorde with the new transparent visor, but it still had the short tail that characterised the prototypes.
It was 02 (F-WTSA), the first French pre-production aircraft, that was close to the final shape of the production aircraft.

7) This one is particularly aimed at ChristiaanJ. What was the total number of gyros on the aircraft?
Good question.... never counted them all. But I'll try a guess.
First a nice one, the SFENA Emergency Standby Artificial Horizon (made by the firm I worked for).
Ran off the Emergency Battery Bus via a small independent inverter.
And if that failed too, it would still run reliably for several minutes on its own inertia.
Next, the rate gyros used by the autostabilisation system ; these measured the angular rate of the aircraft along the three main axes, pitch, roll and yaw.
There were six, three each for the two autostab systems.
Now the rest....
Each IMU (inertial measurement unit, part of the inertial naviagation system) had three gyros.
With three INS on board, that would make nine.
Much as I try, I can't remember other ones, so I'll look forward to the final answer.
I can imagine the weather radar using an additional gyro for stabilisation, but I never went there.

8) How many wheel brakes?
Unless this is a trick question, I would say eight, for each of the main gear wheels.
The nose gear did not have any brakes - unless there were some small ones to stop the wheels rotating after retraction of the gear, but not used during landing.

9) What Mach number was automatic engine variable intake control enabled?
No idea.
Mach 1.0 or thereabouts is my personal guess only.

10) Above each bank of engine instruments were three lights, a blue, a green and an amber. What did they each signify?
I know that they each monitored the status of one of the engines, because it was too complex for the pilots to fully monitor all the parameters of all four engines in the short time between start-of-roll and V1... they had too many other things to do.
But I don't remember what each light meant, would have to look it up in the manual.

11) At what airfied were the first BA crew base training details held?
No idea.
Was it Brize Norton, or Casablanca?

12) What LHR runways did Concorde use for landing and take-off? (Trick question, not as obvious as it might seem).
No idea.
Vague memory of it being systematically the North runway for noise issues.

13) What operator had serious plans to operate Concorde from SNN to JFK in the early 1980's?
No idea.

14) What development aircraft did not exceed Mach 2 until fifteen months after her maiden flight?
I would expect the obvious answer to be 002.
Working up from first flight to Mach 2 was a slow and laborious process, and in the end it was 001 that both flew first, and also went to Mach 2 first.
I don't think any of the other aircraft took that long.

A I said, I tried to answer all questions "off the top of my head", without looking at any other sources.

CJ

OK guys, here are the answers. If you disagree about any of them then fire away, the old memory certainly 'aint perfect.
As many of you have guessed, there were 22: The 14 production airframes, the 2 production series development aircraft (201 & 202), the 2 pre-production airframes (101 & 102) and the 2 prototypes 001 & 002. PLUS, the major fatigue test specimen at the RAE Farnborough and the static test specimen at CEAT in Toulouse. The CEAT tests actually tested the wing to destruction; I seem to remember it was something like a 200% overload before the wing failed at the root. And great but rather sad pictures VOLUME , never seen these before.
OK, from MY memory , we have: London LHR (duhhh!!), Bahrein BAH, Singapore SIN, New York JFK, Washington IAD, Dallas DFW, Miami MIA, Toronto YYZ, Barbados BGI, and Riyadh RUH. As well as charters being ommited, so are some of the special 'surprise' shuttle appearances that Concorde would make, substituting a subsonic to and from destinations such as Manchester and Edinburgh.
11:15
The BA193 and BA 195.
OK, there were 12 engine feed pumps (3 per engine) 8 main transfer tank pumps (2 each for the transfer tanks 5, 6, 7 & 8), 4 'A' tank pumps (2 each for 5A & 7A), 8 trim-transfer tank pumps (2 electric pumps each for tanks 9, 10 & 11 PLUS 2 hydraulically driven pumps for tank 9), 4 electric engine start pumps (there was a single electric start pump per engine that delivered fuel to it's own dedicated start atomiser in the combustion chamber. The pump automatically ran when the engine HP valve was set to OPEN and would continue running for 30 seconds after the DEBOW switch was returned to the 'normal' position), 4 engine first stage pumps (a single mechanically driven pump per engine), 4 second stage pumps (a single pneumatically driven pump, sometimes termed 'the turbopump, per engine. This would cut out at around 20,000'), our scavenge tank pump (triggered automatically when there was 7 US gallons in the tank; pumping it back into tank 2. This pump was identical to an 'A' tank transfer pump), and FINALLY, a single de-air pump for tank 10. The pump would drive the fuel through a mesh, removing air bubbles from the fuel. Tank 11 used the L/H trim pump for de-air (similar principle)and would be switched on during take-off. This is why the tank 5 trim inlet valve being set to over-ride OPEN would result in the tank being highly pressurised in the case of the Gonesse disaster; the pump would obviously pressurise the L/H trim gallery and any tank on that side with an open inlet valve!!!
G-AXDN, aircraft 101. (A production wing, fuselage, droop nose and intakes, but with the short tail section and secondary nozzles of the prototypes.
Ready ChristiaanJ? There were 18....Yes, the single SFENA standby horizon, 9 INS gyros (one per X,Y and Z platform in each of the 3 INUs), 8 autostab' rate gyros (one per axis for each of the 2 autostab' computers PLUS a monitor gyro for the pitch axis). The radar by the way used attitude signals from the INS.
9. One per main wheel plus the single 'in flight braking' nose wheel brake.
Mach 0.7!!! Between this and Mach 1.26 the intake surfaces were positioned as a function of engine N1 if the engine was shut down for any reason. (Otherwise of course the intake surfaces were fully up). You needed a sub idle N1 of 57% and below for all this to happen, and it was to assist relight performance and reduce buffet. Between Mach 1.26 and 1.32 the ramps were driven down slightly to about 5%, full supersonic scheduling itself commencing at Mach 1.32.
Already brilliantly answered by Brit312 (as well as the FSLabs diagram). Yep, Geen GO, T/O monitor armed, fuel flow and P7 at or above datum, A/C on ground, reverse not selected and CON light not on. Amber CON (Reheat selected and not detected, N1 OK or reverse selected and primary nozzle (Aj) not at minimum. Blue REV; steady buckets at reverse, flashing buckets in transit.
Fairford, followed by Brize Norton, and then a host of airfields from Prestwick and Shannon to Chateauroux.
OK, probably no surprises now:
Landing - 27L & R, 9L & R (prior to LHR mag' deviation update were 28L & R & 10L & R) together with 23/05.
Take off - 27L (28L), 9R (10R) and 9L. (10L never happened as take offs on this runway only occurred in 2003).
It was FedEx, they planned to operate two stripped out aircraft, leased from BA, between Shannon and JFK as high value parcel carriers. The idea was that parcels would be flown in from all over Europe by small FedEx feeder aircraft and the parcels transferred to Concorde which would then speed on to JFK in around 2 1/2 hours. It never happened because of a combination of economics appraisal by FedEx and BA deciding that it could would not release the aircraft anyway.
A/C 101, G-AXDN first flew on 17th December 1971 with FIXED INTAKES!! (101 was going to be the launch vehicle for the new digital intake control system, but the 'boxes' were still being designed). This placed an operating limit of Mach 1.5 on the aircraft, limiting her ability with such a restricted flight envelope. She returned to Filton in late 1972 for installation of the system, as well as the new Olympus 593-602 engine. (The engine, very similar to the production Mk 610 version, used a quite revolutionary annular combustion chamber, and eliminated at a stroke the thick smoke exhaust that had up to then been Concorde's unwanted visual signiture). The aircraft flew more or less smokeless on 15 March 1973, achieving Mach 2 soon afterwards. As ChristiaanJ pointed out, the British prototype 002 had a similar gap, actually significantly higher, of 19 months. (The French aircraft 001 had an even longer gap of some 20 months).

I hope you guys had fun with this one, regards to all

Dude

Thanks Dude.

Not quite what I was expecting but very interesting all the same. I see that each finger appears to have an inlet at the base to allow gas flow to alleviate some of the turbulence behind it.

Now to find a picture of a Concorde reheat flame rosette to see how the flame matches up to the finger pattern.

Good game!

Better still, I found a picture of the reheat assembly with the fingers fitted:

Google Image Result for http://heritageconcorde.com/wp-content/uploads/2010/03/reheat-picture.jpg

Did you need all 4 reheats to go from 0.95 - 1.7 ?

If you got to 1.3 and then one or more failed could you continue (albeit with slower acceleration ?)

I presume if you were unable to get the things lit at 0.95 you just turned round and went home again ? The procedure would take around 90 mins so would you need to burn off fuel or already be at acceptable landing weight by that time ?


Also, once when aboard at about 50K-55K feet the aircraft rolled I would estimate 3 degrees to the left and then came back level again almost immediately. I knew this was a glitch but no one else noticed. An announcement was made of a minor problem about 2 mins later and that was that ?

What might have cause such an event (I would guess an airflow issue with intake or engine ?)

norodnik

...Did you need all 4 reheats to go from 0.95 - 1.7 ?...

No.

Two reheats were the minimum for transonic acceleration, however due regard would have to paid to the additional fuel usage with one or two reheats failed.


...If you got to 1.3 and then one or more failed could you continue (albeit with slower acceleration ?)...

Yes, as above, whilst remembering the 15 minute time limit on the use of reheat.


...I presume if you were unable to get the things lit at 0.95 you just turned round and went home again ?...

Yes, once you were convinced that at least three were not going to light up.


...The procedure would take around 90 mins so would you need to burn off fuel or already be at acceptable landing weight by that time ?...

Not something I ever had to do, fortunately, but even so, 90 minutes would seem somewhat excessive to me, given that the aircraft would still have been over the Bristol channel. On a transatlantic sector, fuel jettisoning would have been necessary to get down to 130,000 kgs (for a fuel saving landing) or 111,130 kgs (MLW) if the nature of the failure precluded a fuel saving landing.


...once when aboard at about 50K-55K feet the aircraft rolled I would estimate 3 degrees to the left and then came back level again almost immediately...what might have cause such an event (I would guess an airflow issue with intake or engine ?)...

Any number of things could have caused this, but probably the most likely one is the one you suspected, a (transient) intake problem.


Best Regards

Bellerophon

The engine intake guide vanes were heated [on selection] by a hot air bleed from the exit of the HP compressor. Other than that there was not hot air bleed for anti icing purposes

Now the leading edges of the intakes and the leading edges of various bits within the intake along with the underside of the wing in front of the the intakes were deiced by a combination of continuous and cyclic electrically heated mats.

All of this electrically heated deicing was infact extened engine deicing so as to ensure that when the ice came off it would be in small enough chunks for the engine to digest without damage. [Another system almost direct from the Bristol Britannia]

The fin nor the rest of the wing had any anti icing system

Brit312
mm I guess they were not to blame for flying for over one hour with a red throttle light on (the engine is under no electronic control), resulting in the severe engine overspeed (N1 overspeed protection amplifier already disabled) and the subsequent scrapping (on the orders of Rolls Royce) of the entire rotating assembly of the engine. Or for omitting TWO intake trunnion blocks during a ramp actuator replacement, and then the E/O continually and cyclically operating the intake lane selector switch, following a spill door runaway, until he manages a double engine surge and near destruction of the 'forgotton parts' intake and engine also. I suppose they are not to blame for the experimental tripping of the LPOG circuit breaker by the E/O, during an engine power mismatch, resulting in serious damage to the engine and intake due to the resulting massive over-fueling surge. I suppose again, that they were not to blame for ignoring for over 6 months a simple electrical load defect, eventually resulting in a not too minor fire in the electronics racks that had to be extinguished by the crew with extinguishers. And yet again, I suppose they are not to blame for putting skydrol into Concorde hydraulics systems, almost resulting in the loss of the aircraft, as well as a 9 month grounding while all of the hydraulic components were replaced. And it was not Air France that hammered Fox Delta twice into the runway at Dacca, resulting in so much airframe distortion that the aircraft performance was seriously compromised (and eventually broken up). And of course they were not responsible for the technical and operational failures, including the (forgotton AGAIN ) missing spacer and overweight take-off etc.) on 25th July 2000. Silly me.
And although I might have said 'precautionary engine shut-down', we are talking about a quite an eventful episode here indeed, you can NOT excuse the further mistakes made on that day, 'just because they are poor old Air France. With the greatest of respect Brit, there are 3 crew members on that flight deck, do you not think that the loss of over over 5 tonnes of fuel over a period of time might just be noticed????? The subsonic 3 engined leg was carried out for quite a time before it computed to them that they were still losing fuel. There is no excuse for flying with your eyes closed, I'm sorry.
For goodness sake, this is probably the biggest single episode that was behind the demise of Concorde, poor Air France my eye!!!

Dude

My physics has pretty much rusted away so can anyone help me with this, The frequent statement that the intakes accounted for approx 80% of the engine power when supersonic. I quite understand that the intake air has to be slowed to subsonic before it meets the first compressor disk but saying that the intake produces 80% of the power almost implies that you could turn off the fires and still have 80% power. Obviously that cant be right! and another thing I dont understand is how shock waves slow down the intake flow, so any help with that would be useful to me. Any aerodymicist/physicists out there?

Thanks and keep up the super remeniscences
rod

jodeliste ,
That question already ended up in a separate TechLog thread... LOL.

Concorde engine intake "Thrust"

Have a look there first, then if things still aren't quite clear, feel free to ask more questions!

CJ

I have to admit that some of the subsonic fuel burn figures for Concorde were truly eye watering, and without massive engine and airframe modifications there was precious little in service that could be done to improve things. Paradoxically improvements to the supersonic efficiency of the powerplant were easier to implement, and several modifications were implemented, tried or proposed to improve fuel burn:
Way back in the late 1970's we did a major modification to the intakes that increased capture area by 2.5% and gave us typically a 1.6% improvement in trans-Atlantic fuel burn, and although this was our biggest performance improvement modification, there were more:
The famous elevon and rudder trailing edge extension modifications (that due to poor design, produced in later life the water ingress induced honeycomb failures) together with the re-profiled fin leading edge modification, I never saw the performance gains quantified (anyone have any ideas?).
Can anyone here remember the riblet trial? In the mid 1990's Airbus supplied 'stick on' plastic riblets, applied to various areas on the under-side of the wing on G-BOAG. These riblets had very fine undulations moulded into the surface; the idea being that as the air flowed through and around the riblet patches, boundary layer turbulence, and hence induced drag would be reduced. Now, the performance gains (if any) were never quantified, mainly because the riblet patches either peeled off or the surface deteriorated with the continuous thermal cycle. (I was over in JFK when the aircraft first arrived after having the riblets fitted, and as the crew were trying to proudly show me these amazing aerodynamic devices, they were sadly embarassed, as several had dissapeared in the course of a single flight).
There was one modification, proposed by Rolls Royce in the late 1990's that did have quite a lot of potential; this was to increase the engine N1 by around 1.5%. This would have had the effect of increasing engine mass flow and therefore reducing the drag inducing spill of supersonic air over the lower lip of the intake. Depending on the temperature, the performance gains were in the order of a 1.5% improvement in fuel burn at ISA Plus upper atmosphere temperatures ('normal' LHR-JFK) to none at all at significant ISA Minus temperatures (LHR -BGI). The modifacation had been trialed on G-BBDG before her retirement in the early eighties, and was proven in terms of performance enhancement and engine stability. In order to keep TET at the pre-modification level, there was a small increase in N2 commanded also. (The higher N1 required an increase in primary nozzle area, reducing TET). The main reason for the modification not being implemented was one of cost; The Ultra Electronics Engine Control Units were analog units, and the modification was a simple replacement of two resistors per unit. However because ultimate mass flow limitation was also controll by the digital AICU (built by British Aerospace Guided Weapons Division) the cost of getting a software update for this exremely 'mature' unit was found to be prohibitive.
A certain 'brainy' SEO and myself were working on a modification to improve fuel burn on ISA minus sectors. The idea was to force the autopilot, in Max Cruise at low temperatures only , to fly the aircraft close to Mmo, rather than at Max Cruise speed of Mach 2 - 2.02; this would have given us gains of up to 1%, depending on the temperature. The basic electronics involved for the modification were relatively straightforward, but it was never pursued due to the complexity of dealing with temperature shears and the cost of certification.

Dude

Oh darn it Feathers, if you insist (LOL).
First of all, what is rotating stall? All gas turbine engines are prone to this to some degree or another, the Olympus was particularly prone (so we discovered to our cost). What happens is that extremely LOW figures of N2, small cells of stalled air rotate around the anulus of the early stages of the HP compressor (at approximately half the rotational rpm), resulting in parts of the airflow becoming choked and highly distorted. This often results in the combustion process being disturbed to the extent that combustion instead of occuring in the combustion chamber, occurs in the turbine itself. This of course results in massive overheating of the turbine blades and stators (and is what is suspected occured in the #2 engine on G-BOAA in 1991.
To prevent running in rotating stall, the Olympus automatic fuel start schedule would accelerate the engine quickly to around 67% N2 before dropping back to the normal idle figure of around 65% N2. (The stall clearance N2 figure was ambient temperature dependant, the higher the temperature the higher the N2 that was required and hence scheduled by the automatics).
What had happened on G-BOAA was an engine starting/accelerating problem, where the N2 ran at a sub-idle of around 40% N2 for several minutes. This was enough for the malignant effects of rotating stall to take hold, and the resulting turbine blade failure over the Atlantic the following day. In all fairness to everyone involved, none of us, including Rolls Royce realised just how potentially serious this phenonomen was, and salutary lessons were learned by one and all. (The following year Air France had a similar failure; their first and last also).
I flew out to Shannon on a BAC 1-11, that was sent to fly the Concorde passengers back to London. As I and my colleague were coming down the ventral door steps of the 1-11, a chirpy Aer Lingus engineer asks 'have you guys come to fix the broken engine?, there are bits of it lying in the jet pipe'. Now up to now, from the information we'd been given in London, we thought that we were going to be looking at either an intake or engine induced surge, a few systems checks and boroscope inspections and we'd all be on our way, so we naturally thought the Aer Lingus guy was joking. He was most certainly was not; as you looked into the jetpipe (through the secondary nozzle buckets) you could see a large quantity of metal debris, accompanied by a strong smell of burnt oil. I remember this day well, it was the day that the first Gulf war ended; how ironic.
The aircraft departed on three engines, flown by a management crew late the following day, my colleague and I returned to London by Aer Lingus one day later. (No passengers whatsoever are permitted on ferry flights, even expendable ones like me).

Dude

M2Dude wrote:

You'd have to say that designing and building the aeroplane probably isn't the tough issue. I mean you could probably adapt a military design - a Tornado can lift more than six tons of stores can it not? So that's a ton of people, a ton of bling to keep them comfortable and four tons of fuel ...... oh.

The tough thing needed, the really clever thing that Concorde did and no other aeroplane, sorry, only one other aeroplane - our 'honorary Concorde' the SR71 - would be to design the engine /intake /nozzle configuration that would let our 'Tonkorde' supercruise at Mach two, while running on the smell of the stuff.

Roger.

Sorry Dude, didn't realise that use of the 'T' word would upset you so! Perhaps you were frightened by one when you were a baby? I picked the T*****o randomly to illustrate the contrast between a military supersonic design and Concorde. She really wasn't a converted bomber and even by using up every ounce of a Tonka's lifting capacity, it would still run out of fuel before it reached the Fastnet Rocks, let alone anywhere useful.

I must have missed something about the SR71 while we were discussing 'Inlet Thrust' on the other thread. I thought there was at least some part of the performance envelope where the Blackbird 'supercruised?' If not, then Concorde's ability in this area is all the more astonishing.

While mentioning the SR71, a striking image of them - to me anyway - was of the streams of fuel, leaking from every seam of the fuselage immediately following in-flight refuelling. These apparently 'sealed up' when she expanded in supersonic flight. How did Concorde avoid this rather startling phenomenon?

Roger.

Hello all to all members and Concorde Expert,

I have been read this thread and it is so great. I'm enjoy reading it all day long!!
I have some question that I'm wonder about the Concorde.

1. I've heard that Concorde use the primary nozzle to modulate the noise and
the speed of the N1 compressor. How does it work? and does it help to reduce
the noise a lot?

2.Another thing about Primary nozzle. If i recall it correctly, the primary nozzle
can also use to control the Inlet Turbine temperature. Is that true? How is that work?

3.Finally, does some one have a schematic or the fuel vent system?

That's all of it. I will transform in to a nerd man reading a Concorde book in
the next couple days.

Thanks for all of yours reply.

Mr Vortex
First of all, 'welcome aboard'; I'll do my best to answer your queries.
The area of the primary nozzle Aj, was varied for 2 'primary' purposes :
a) To act as a military type 'reheat' or 'afterburning' nozzle; opening up to control the rise in jet pipe pressure P7, as reheat is in operated.
b) To match the INLET TOTAL TEMPERATURE RELATED (T1) speed of the LP compressor N1 to the HP compressor N2 against a series of schedules, ensuring easch spool is as close as safely possible to its respective surge boundary, (with a constant TET, see below) and therefore at peak efficiency.
Now, in doing this a complex set of variables were in place. As the nozzle is opened there is a REDUCED pressure and temperature drop across the LP turbine. This has the effect of enabling a HIGHER N1,as less work is being done by the turbine. Also the change (in this case a decrease) in the temperature drop across the turbine will obviously affect the turbine entry temperature, TET. A closing down of the nozzle would obviously have the opposite effect, with a DECREASE in N1 and an INCREASE in TET.
In practice at a given T1 there was always an ideal N1 versus N2 on the control schedule (known as the E Schedule), the TET staying more or less constant from TAKE-OFF to SUPERSONIC CRUISE!!
As far as noise abatement went; when reheat was cancelled and power reduced after take-off, an E Schedule known as E Flyover was automatically invoked. This had the effect of driving the primary nozzle nearly wide open, reducing both the velocity of the jet efflux and in essence the noise below the aircraft.
The real beauty of this primary nozzle system was that it really did not care if the engine was operating dry or with afterburning ('it' did not even know). P7 was controlled against a varying compressor outlet pressure, the variable being controlled by a needle valve operated by the electronic engine controller. (If this is unclear I can post a diagram here that shows this control in action).

As soon as I receive back the majority of my technical notes that I have out on long-term loan (I've requested their return) I will post a schematic here. But for now; The tanks were vented to atmosphere via tandem vent galleries, the two vents openings being on the left hand side of the tail-cone. At an absolute static pressure of 2.2 PSIA (around 44,000') twin electrically operated vent valves, also in the tail-cone, would automatically close; the tanks now being pressurised via a small NACA duct on the right side of the fin. A tank pressure of around 1.5 PSIG was maintained by the action of a small pneumatic valve at the rear of the aircraft. There was massive protection built in to guard against over-pressure (eg. if a tank over-filled in cruise).

I hope this answers some of your queries
Best Regards

Dude

Landroger
It always was a bit of a paradox; in terms of fuel price and environmental concerns, Concorde was about 5 years too late. But in ELECTRONICS terms she was 10 years too early. Bearing in mind that the first Intel 4004 was not even commercially available until 1971. When the decision was taken in late 1970 to 're-design' the analog air intake control system into a digital one, there was nothing to fall back on; a BAC custom guided missile processor (used I believe on both the Rapier and Sea Dart SAMs) had to be adapted. This processor was, as I've yawned on about before, comprised of multiple double sided PCBs completely stacked with TTL ICs. In spite of being a total antique and a dinasore (just like me ) this thing was really cutting edge technology at the time, even using a 64 bit data word. The AICS as again I've yawned on about before, was the WORLD's first commercial airborne digital control sysstem, but the Concorde analog stuff in fact worked pretty well indeed.

Galaxy Flyer
As always GF you make your point really well. As far as Concorde went, the very few American (Branniff) pilots who flew her thought she was totally amazing, and the American BA engineers at JFK and IAD absolutely adored the aeroplane.
And back to your 'charriot', the C5 has been a staggeringly successful aeroplane in terms of US service. and is still thriving (big modernisation programme underway). Not bad for an aircraft that entered USAF service in 1969!!!
Regards

Dude

EXWOK
I think you will find it was 18\xb0 TLA mate (age catching up with us??? . OK I know it has been 7 years).
The 18\xb0 TLA limitation was set to prevent TOD 'pop' surges, due to the resulting large intake ramp angle causing excessive compressor face distortion (the one side effect of the intake 'thin lip' modification).

Best Regards
Dude