Posts about: "INLINE_IMAGES" [Posts: 122 Page: 2 of 7]¶

Chu Chu ,

You're quite right, actually, especially assuming no flow.



"how would the fluid in the "cylinder" "know" it's pressing against pressurized hydraulic fluid in the inner tube and not a solid steel piston? "

The fluid wouldn't "know".. It would be pressing against pressurized hydraulic fluid further down the line.... but at the end, it would finally be pressing against the piston of a hydraulic cylinder of some kind at the end, like the 'cap' in my first scribble.
If nothing was restrained "downstream", indeed everything would be "blown apart".
Of course, that hydraulic cylinder (my 'cap') would be affixed to the structure, so it wouldn't move.

The problem is more like my second scribble.... with a bend in the pipe, and only the final 'cap' fixed, the pipe would continuously flex under pressure.... not a good idea at all, especially when the pressure in the pipe varies, because the 'cap' is not a real 'cap' but something like a PFCU (power flight control unit), with continously varying demand.

So yes, the hydraulic lines are restrained in all the right places, for the hydraulic expansion seals to work correctly without setting up stresses in the lines themselves (except for the pressure acting outwards, of course).

Hope this makes sense to you?

CJ

Subjects Expansion  Hydraulic  PFCU (Powered Flying Control Units)

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Quote:

Originally Posted by Cron

My question concerns lighting. Not many decent pictures showing landing lights etc being used in anger.
Concorde appears to have a much reduced frontal area for the housing of such lighting.

Quite right!
Nevertheless there were three separate sets of landing/taxi lights there.

Quoting from the manual:

Two main landing lamps, one mounted in each wing root leading
edge, have retractable/extensible mountings and when not in
use are retracted in the lamp housing.
Two land/taxi lamps, similar to the main landing lamps, are attached to the
nose landing gear bay doors. The land/taxi lamps extend to
an intermediate position for landing, upon which they
automatically extend to the full position for taxiing, thus
changing the beam angle to compensate for the attitude change.
Two taxi/turn-off lamps, one mounted on each side of the
forward fuselage, provide ground illumination to identify
runway turn-off points.


These are the 'main' lights in the wing leading edge (600W each).





These are the lights in the nosewheel doors ("only" 450W each).

Quote:

There is also the question of lenses having to withstand supersonic flow.

All three of the sets of lights had a cover to blend them in smoothly with the structure, much like the cabin windows.

The heat was less of a problem, actually.
The lights themselves were high-power sealed-beam units, the main units were 6 00W each, and the ones in the nosewheel doors were 450W ... nothing like your car headlights.
As a matter of fact, on the ground you were not suppossed to turn them on any more than 5 minutes in any 10 minutes.... they got a lot hotter when switched on, than they did in supersonic flight.

Quote:

And also the angle of attack on landing (hope I have the right terminology there) seemingly pointing any lighting into the sky.

Good point!
What happened was that the main landing lamps in the wing roots were angled such, that they pointed straight ahead at the right angle to "hit" the runway during the landing itself.
Once the aircraft touched down, the land/taxi lights in the nose gear door extended further and lit a wider expanse of the runway ahead (see the earlier quote from the manual).
And then the third set of lights in the nose helped you to find the turn-off to the taxiway.

One nice little detail.... on F-BTSD, the Concorde at the French Le Bourget museum, those lights still work, and on G-BBDG, the Concorde at the Brooklands museum that was saved from the scrapheap, they brought those lights back to life, too.

CJ

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Last edited by ChristiaanJ; 28th September 2010 at 23:14 . Reason: Addng pics and typo

Subjects Brooklands  F-BTSD  G-BBDG  Landing & Taxy Lights  Landing Gear  Le Bourget

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Quote:

Originally Posted by EXWOK

In service we tended to use only the wing-mounted main landing lights, as the nosegear door-mounted lights caused light buffeting which could be felt in the cabin.

Interesting.
Judging by the picture from the maintenance manual below, once the nosewheel was down, the main landing lights just lit up the ground below the nose, but not ahead.
Did you just rely on the runway lighting plus the ambient light (town lights reflected by the clouds, etc.) or did you usually extend the nosewheel door lights once you were down?





CJ

Subjects Landing & Taxy Lights  Landing Gear

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Feathers McGraw

Quote:

I presume that the fuel penalty for a locked secondary nozzle was due to the reduced expansion of exhaust gas without the maximum divergent shape?

The 10 degree lockout position was a bit of a compromise, to allow the aircraft to operate throughout the normal operating envelope with a secondary nozzle (bucket) at a less than ideal position. See the diagrams below, one showing the bucket control schedule and the other the bucket positions at both take off and supersonic flight: If the buckets are too wide at low Mach numbers then the high velocity exhaust will try and 'drag' the low pressure/low velocity air in the exhaust annulus along with it; this results in a huge reduction in thrust and is termed 'base drag'. That is the whole idea of having the eyelids at the top and bottom of the bucket assembly; to admit free ambient air into this void and mitigate the effects of base drag (and reduce the noise mayhem a little too). If however the buckets are too narrow at high speed/high altitude then we really get a problem; The high pressure/high velocity exhause gas immediately expands against the VERY low presuure ambient air and flares outwards at an accute angle, again losing us serious quantities of thrust The wide open bucket angle gives us this wonderful cushion of secondary intake airflow. (travelling over the top of the rear ramp, through the engine bay and into the nozzle annulus. The eflux can now gently expand against this airflow as it exits the secondary nozzle, taking up the shape of the divergent secion of nozzle.
Now if we are locked at the 10 degree position we are at a position that will give us significant but tolerable losses throughout the flight envelope.

Subjects Expansion  Flight Envelope  Intakes  Nozzles  Thrust Reversers

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Dixi188

Quote:

I heard that the combined nozzle and reverser was a unique piece of aviation development.
The story I heard when I was an apprentice at Hurn was that, compared to the prototype multi finger nozzle and separate reverser, the production nozzle was:-
1. More efficient.
2. Lighter.
3. Simpler.
4. Cheaper to make and maintain.

Actually Rolls Royce always told me that the (new) Type 28 secondary nozzle was a bit of a dissapointment. Aerodynamically it was a far better interface with the wing from a drag point of view than the original design, but fell short of it's design promise in terms of performance. The design responsibility for the secondary nozzle system awarded to the French engine manufacturer SNECMA. They in turn farmed the whole manufacturing side off to STRESSKIN inc., a division of General Motors, and the air motor and electronic control unit were designed and built by Garret Airesearch in the US also.
The original secondary nozzle was 'freely floating, with no actuation; the thrust revereser itself was a pair of cascade doors, driven by an air motor. Tertary air doors opened at low speeds to admit ambient air into the nozzle anulus, instead of the eyelids of the later 'buckets'.
If you look at the diagram below you can see what a complicated animal the prototype powerplant was. The intake dump door (alternative name for spill door) was hinged both at the front AND the rear; either hinge mechanisms automatically releasing at specific Mach numbers. It was the mechanical nightmare that the diagram suggesrs.

Dude

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Last edited by M2dude; 9th October 2010 at 21:54 .

Subjects Intakes  Nozzles  Rolls Royce  Thrust Reversers

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Quote:

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.

That one is sadly rotting away in the Ailes Anciennes aircraft museum storage area exposed to the Toulouse weather...


Left Upper Wing Skin


Right hand passenger window, rear fuselage


Seat tracks, forward cabin looking aft

At least it was in 2008, maybe it has been scrapped in favor of the A350 production line by now.

Subjects Toulouse

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The green 'Go' configuration light depends on the following flowchart:

Ess 28v DC Busbar -> Fwd Thrust Selected -> Arming Switch 'On' -> Landing Gear Relay Operated -> Fuel Flow Attained -> Jet Pipe Pressure (P7) Attained -> Bucket Position Correct -> 'GO'.

How were these engine parameters monitored? (From the AMM)

- Arming Switch 'ON' : it's a manually operated four-pole solenoid-held switch, for the four engine circuits, operative only when a landing gear weight switch is energized.

- Fuel Flow and Jet Pipe Pressure (P7) Attained: Once the circuit to the 'Go' light is armed, the flow and pressure are monitored against the values set on the indicator bugs on the respective instruments. Once they pass those values, their respective change-over relays are energized, completing the circuit.

Here's a simplified schematic for this:



At least I think that's how it works .

Lefteris

Subjects Fuel Burn  Landing Gear  Thrust Reversers

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Concorde Reheat

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Consider it done Feathers.
As promised, here are a few diagrams of the Concorde reheat (afterburner, for our American friends) system. The ORIGINAL design was done by SNECMA, but due to them getting into all sorts of trouble with the fuel injection system and flame stabilisation, Rolls Royce baled them out, and it became a Rolls Royce/SNECMA design. (The core engine was a 100% Rolls design, with no French input whatsoever. However some engine sub-assembles were manufactured by SNECMA).
The basic way the afterburner worked was by spraying the fuel FORWARDS intially at high pressure, against the jet stram about one inch, until it hit the anvil. . As the fuel strikes the anvil it is blown back by the jet stram and atomises, passing over the of the spray ring and the over the flame holder. The ignition operated by passing 15KV across a dual cylindrical tube, the resulting arc was 'swirlied' into the fuel stream by blowing engine 5th stage HP compressor air into the tube (there were 7 stages in all).
The key to successful ignition was a healthy spark, a good supply of air to the ignitor and accurate scheduling of fuel flow. (This was scheduled against dry engine flow as a funtion of total temperature). The other important factor (as with any afterburner) was correct and rapid operation of the exhaust nozzle. Fortunately, Concorde used it's primary nozzle for control of engine N1 anyway, so adapting this to operate as an afterburning nozzle also was a relative walk in the park, and it operated superbly.
During the light up phase of 3.5 seconds, the fuel ratio is a fixed 0.45 (ie. reheat fuel is 45% of dry fuel). After the light up phase the full scheduling commenced. As far as the FLIGHT RATING figures go (not take-off) the ratios were 0.6 at a TAT of 54 deg's C, falling linearly to 0.3 at 107 deg's C and above. (Remember that Concorde used afterburning really sparingly, just for take-off and then transonic acceleration; cut off at Mach 1.7 altogether.

Dude

Subjects Afterburner/Re-heat  Fuel Burn  HP Compressor  Ignitors  N1 (revolutions)  Nozzles  Rolls Royce  TAT (Total Air Temperature)  Transonic Acceleration

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Here you go Feathers, it's in French but you can see what the modification did. (Before the modification was embodied there was an RTOW limit placed on the aircraft; perhaps Brit312 can remember the figures? OH, and as to the contingency time limit (which I forgot to answer your quesy, soorry ) it was 2 1/2 minutes. (The only time that I can recall the limit being accidently exceeded we told Rolls Royce who after a few minutes of head scratching came back with a 'no problem man, don't worry about it ).
Regards
Dude

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Last edited by M2dude; 25th October 2010 at 22:22 .

Subjects Rolls Royce

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Quote:

The entire collection of "Ailes Anciennes Toulouse" has been moved to a different location only very recently... one can merely hope that at least some of the bits and pieces of "0001" have survived...
Maybe VOLUME can tell us more?

Sorry, no. Haven\xb4t been there for more than a year and at that time it was just clear that they have to move due to the A350 FAL, but the details were not decided.
Found one more picture...

Sad to see this masterpiece of engineering rotting away.
I always thought that the sloped area at the aft end of the floor was the rear airstair (just present on the pre-production aircraft), but I just read on heritageconcorde.com/ that this is for "system routing". Does somebody know more ? Seems to be a lot of space for systems that would end just in the middle of the cabin.

Subjects Toulouse

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Volume ,

Here are the drawings that should help with your last photo of Concorde "0001".
Not very good quality, since they're scans of xerox copies of xerox copies of microfilm ...

Prototype drawing dated July 1965, which in particular shows the location of the emergency exits.



Production drawing (two cut-outs from the same drawing at the same scale) which (schematically) does actually show the 'sloped areas' both at the front and the rear of the main landing gear bay.






Note 1 : both frame 54 and frame 60 were 'production breaks'.
Note 2 : the tanks were numbered differently on the prototypes ; tank N\xb0 9 on the prototype became tank n\xb0 6 on the production aircraft.

CJ

Subjects Landing Gear

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Quote:

Originally Posted by Biggles78

All due respect but this is the CONCORDE thread and it would be really nice if it could stay as such.

I would say that the SR-71, and the Tu-144, are in a way honorary members of the Concorde family, so I don't mind if they fly into the discussion every now and then.

Quote:

LandLady said in a post many moons ago that there was a pool of some 240 "Concorde Ambassadors" (sorry but CC and FAs don't sound right for this aeroplane) for Her. What was the numbers of Captains, First Officers and the all important Flight Engineers (sucking up to M2 with that one )

The full list of names (up to 2002) for both BA and AF can be found in "The Concorde Story" by Chris Orlebar. For BA, a quick count shows about 170 names. That book also mentions, that the maximum number of crews qualified at any one time was 28, in 1980, and that the average was about 20 crews.

Quote:

I looked at the photos posted by a thoughtful member in an earlier post and wonder how former crew felt looking at them. The photos give the impression that you could kick the tyres and light the fires and they would be once again gracing the skies. Obviously they are unairworthy BUT the photos project a different image.

Photos can lie.... or rather, they are rarely close-up enough to show clearly where corrosion has set in.

As an example, F-BVFC at Toulouse, which was the last one to remain at least taxyable, now has some patches of corrosion starting to show, when you know where to look. Not to mention the nasty smell of damp and mould in the cockpit which bodes no good for what's going on underneath the floor.

And even F-BTSD, kept "live" to some extent at Le Bourget, leaks some hydraulic fluid (like all Concordes did on the ground), so it's easy to imagine the dried-out hydraulic and fuel seals on the other museum aircraft.




And yes, that's kitty litter...
The composite material of the floor and the hydraulic fluid don't agree too well.

Quote:

Final one for this post. If She was still flying, do you still think that BA (sorry but going to ignore AF on this one) would have sufficient patronage to keep Her as a going and profitable concern?

I'll leave M2dude to answer that one.

CJ

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Last edited by ChristiaanJ; 14th November 2010 at 11:32 . Reason: typo

Subjects Air France  British Airways  Cabin Crew  Captains  Corrosion  F-BTSD  F-BVFC  Hydraulic  Le Bourget  SR-71  Toulouse  Tu-144  Tyres

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Mr Vortex

Quote:

- So once we select the Engine schedule to mode Hi or F/O the Prim nozzle will open wider causing the pressure at the Prim nozzle to drop and hence the higher flow of the exhaust through the LP turbine = Higher N1 RPM. Am I understand it correctly?

More or less you are correct yes, but remember that schedule selection was more or less automatic. ( E Flyover was armed prior to take-off, and E-MID during approach by the E/O, otherwise it was more or less a 'hands off' afair).

Quote:

According to your reply, the E schedule that will provide the most thrust is the Low mode since the prim nozzle area will be the smallest among all of the other mode which mean the highest pressure and temperature. Am I understand it correctly? And if so why do BA [as far as I know] told the FE to use Hi mode? Because the higher thrust can be obtain with higher N1?

Oooo no, we are way adrift here I'm afraid. I'm trying not to get too 'heavy' with this explanation, and I've enclosed below the Rolls-Royce E Shedule diagram to try and help clarify everything. (I've edited out the exact equation figures in deference to Rolls-Royce). Where N1/√θ and N2/√θ is quoted, the term ' θ ' related to T1 in degrees K/288 . (288 deg's K being 15 deg's C). The hotter things are the higher the spool speed scheduled is, and visa-versa for lower temperatures. Only at a T1 of 15 deg's. C (Standard day temperature) does N/√θ equate to N. (But remamber that T1 is TOTAL temperature, that varies with Mach Number).
The use of E LOW above 220KIAS was not only strictly inhibited by the automatics, if you over-rode the automatics and 'hard selected' E LOW , the aircraft would fall out of the sky when reheat was cancelled at Mach 1.7. This was because the low N1/√θ scheduled by E LOW would now invoke an N2/√θ limit (The E3 Limiter in the diagram) and claw off fuel flow by the tonne.
The most efficient schedule for supersonic cruise was E HI which again would be automatically selected.
E-MID was automatically selected during afterburning operation, to minimise the chance of an N1 overspeed on cancellation of reheat. E-MID could also be selected by the E/O for noise abatement approach.
E Flyover was as we discussed before used for take-off flyover noise abatement as well as subsonic cruise if desired. (If Mach 1 was exceeded with E Flyover still selected, a yellow NOZZLE light illuminated and E HI would be automatically selected.
I sincerely hope that this blurb is not clear as mud, feel free to ask away.

Quote:

- Also does the the Hi mode can deliver the higher N1 RPM, does that mean the Engine control unit must deliver the higher fuelflow rate in order to keep N2 run at the constant speed [higher N1 speed => higher pressure => more resistance
=> higher Fuelflow require to keep N2 run at constant speed]

Nope, that is the beauty of it all. Because of the part choking of the LP turbine section of the engine, the pressure changes due to Aj variation were felt exclusively by N1 and not N2. (Clever, these Rolls-Royce guys ).
Regards

Dude

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Last edited by M2dude; 18th November 2010 at 15:04 . Reason: I goofed.. (another sign of age)

Subjects Afterburner/Re-heat  British Airways  Fuel Burn  LP Turbine  N1 (revolutions)  Noise Abatement  Nozzles  Rolls Royce  Vortex

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Quote:

Originally Posted by jodeliste

Why were the Olympus 593 s so smoky to start with, did they use excess fuel to help with cooling as some petrol engines do, or was there some design feature which caused the smoke? It seems to have been cured in later engines.

It was indeed a design issue.

The 593s on the prototypes had eight separate combustion chambers, and used fuel injectors ; the smoke resulted from the less-than-perfect combustion (as on many earlier aircraft types).

The 593s on the pre-prod and the later production aircraft had a single 'annular' combustion chamber and fuel vaporisers (the fuel entered the gas stream fully vaporised rather than as a fine spray).
While it didn't totally eliminate the smoke (as any take-off video shows...), it did make a huge difference.

It was unfortunate, that the new engines were not there in time for the prototypes, so that during the prototypes' world tours they acquired a repution of 'Smoky Joes', and gave an un-needed and undeserved boost to the tree-huggers of the time.

CJ


PS Here's another explanation....



(And no, the drawing isn't mine)

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Last edited by ChristiaanJ; 25th November 2010 at 16:57 .

Subjects Olympus 593

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Quote:

Originally Posted by CAAAD

Dude - I think basic engine hardware was in good supply.... We have a couple of Olympus intake blanks which we find absolutely perfect for gardening with our aged knees.

Yes, I can imagine they would be perfect for that!
Not to mention the vast quantity of spare compressor and turbine blades and stator vanes, spread far and wide after the end-of-service, through the spare parts auctions.



(The model is a design that was part of my engineering studies - late '60s - but the compressor vane is real Concorde.)

Quote:

....but there were concerns about the control amplifier component availability.

Tell us more?
M2dude and myself already have mentioned the same problem with the AICU (air intake control computer) in this thread.
People do only rarely realise how rapidly technology was changing in the early Concorde days, and how difficult it was to procure components that sometimes were already obsolete when Concorde entered service.

CJ

Subjects AICU (Air Intake Control Computer)  Intakes

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Dude, only 5 seconds ?? I'd demand a re-edit mate...outrageous !

Out of interest...here is a pic of AG in Seattle ( taken a while back ) and the source of a big part of this thread - unfortunately could not get any higher in order to get a better view...on either end ! ( I need to check on her again and see how she is doing ) and the SR71 also ( from the Pima Air / Space museum in Arizona) - I am sure all have seen the Concorde intakes but the SR71 rear end is interesting....

ps Please forgive the pic of the Sikorsky ( at Pima also ) ...couldnt resist

Cheers...

Subjects Intakes  SR-71

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Quote:

Originally Posted by Trabbi

... on board the Lady (what was the nick for her at AF as someone (ChristiaanJ?) mentioned at AF the Concorde was a "he"?)...

Did you ever wonder what happened when a British and French Concorde ended up at night in the same hangar, all by themselves?

Some of it can now be told.....

From the secret archives.



CJ

Subjects Air France

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Quote:

Originally Posted by ChristiaanJ

Only rare samples got saved.... there's a great photo of the shadow of the Lear Jet on a Concorde, that's still around.

Just found it on my hard disk, thought it was worth sharing.



Taken during the filming of "Airport 79 - Concorde".

CJ

Subjects: None

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Fuel tank vent and pressurisation

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Mr Vortex

Quote:

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

Finally as promised, here is a schematic of the AFT part of the fuel vent system. As you can tsee the fin intake pressurises the air space above tank 11, and hence, via the Scavenge Tank air-space, the remaining tanks. (Also you can see the Trim Pipe Drain Vaves you were asking about.



Regards Dude

Subjects Fuel Vent System  Intakes  Trim  Vortex

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Quote:

Originally Posted by Nick Thomas

So my question to all you Concorde admirers is do you have a special Concorde image and if so would you be kind enough to share it with us?

I know exactly what you're saying, Nick...

And yes, Concorde evokes images like no other aircraft really does.

Funnily enough, to me the image you describe always evokes something totally different... although it does depend on the exact angle it's taken from.
Seen from exactly the right angle, she has this slight 'smile' on her face, saying "did it again, people... home soon ! ".


Otherwise, oh yes, I have two images.... both sad.

One is the air-to-air video of the Jubilee flypast with the Red Arrows (I don't have the link at hand), when she pulls up and away, saying goodbye.
For some reson, I have never been able to watch that one without a huge lump in my throat.

The other one is this one....



Last time ever.... and somehow one hoped an instant she would disappear from view, and return forever to the sky where she belonged.

And why should I now be furiously rubbing my eyes?
But maybe that answers your question, too....

Christian

Subjects: None

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