Posts about: "Olympus 593" [Posts: 44 Pages: 3]

M2Dude

There was an unconfirmed report - so no doubt completely baseless - that ...er...another operator... noticed a rather unusual but highly favourable wind component on a JFK...er...Easterly... crossing, as they passed through FL520 or so, giving them a magnificent groundspeed.

Deciding that they would like to maintain this groundspeed, they went ALT HOLD and MACH HOLD at around FL530. They maintained their groundspeed, so the story goes, but the autothrottle then progressively reduced the N1, as the aircraft weight reduced, over the next couple of hours, into the prohibited range!

Did you ever hear of any such event?

Best Regards

Bellerophon

Bellerophon
Ahhh this 'other operator' (I'd quite forgotten our code for *** ******). And as for this obviously baseless story .... er yes it did happen. I should really have qualified my post and said 'The controlled N1 as long as the aeroplane was operated CORRECTLY was always at least in the upper 90's, well away from our blade resonance area'. I don't quite recall after the engines were removed post-flight (At Rolls-Royce's insistance) whether the entire LP compressor sections or just the first few stages had to be replaced at the engine overhaul base. In either case it was a rather expensive piece of experimentation.

ChristiaanJ
Certainly my friend (but hey, remember that I'm an old Volts and Amps and Ohms ancient at heart too ).
The lighting of a reheat flame can be achieved in three ways:
1) By using an electric arc ignitor.. the least reliable system, although relatively simple in concept.
2) Catalytic ignition, where the reheat fuel is sprayed over a platinum based catalyst, spontaneously igniting. I recall that although generally reliable, eventually the catalyst compound erodes away and you are left with no ignition source.
3) Hot streak injection (or ignition). I this case a sizable jet of fuel is injected through a single injector placed the the combustion chamber of the engine, a powerful streak of flame then 'shoots out' of the turbine, and ignites the reheat fuel. Generally reliable as long as the injector itself does not carbon up (as our new friend Howiehowie93 pointed out). What amazed me with this system when we were looking at it for Concorde, was that the Olympus 593 designer I spoke to at Rolls-Royce told me that it has a negligible effect on turbine blade life, as the hottest part of the flame does not hit the blades themselves, and also of course it is a very short duration burn anyway (1 - 2 seconds).
And Christian my friend, you should indeed 'rabbit on' here about some of your observations regarding Concorde electronics technology, you have a unique insight here as (probably) the only Concorde systems designer that regularly visits 'here'. I'm sure I speak for many of us here when I say that your experiences are unique and your contributaions are always illuminating. Come on, let's have some Volts/Amps and Ohms

Best Regards
Dude

IMHO I'd the simplicity of the design. I have worked on many flavours of Gas Turbines since I left the RAF in 2000, GE, RR, Rustons, (EGT, RGT the same really just a name change every few years and now Siemens) oh and Solar - who I work for now - better not forget them !!

All these engines from other manufacturers have complicated systems to make them efficient:
VIGV's (Variable Inlet Guide Vanes)
VSV's (Variable Stator Vanes)
Bleed Valves
Multi Fuel Metering Valves & other valves to keep emissions under control.

The Olympus - nowt ! Two Spools and a Fuel Valve thats your lot. nothing to go wrong and being an Aeroderivative all the ancillary equipment is either bolted on underneath or away from the engine outside the enclosure.

The only thing I had trouble with was the burner bolts shearing off, 1/4"BSF, if never touched in a good few years !

Was it all still BSF on the 593? That was a Bristols thing - true RR designs are UNC (well Avons are anyway)

oh ! I forgot about the Hot Shot; when I was ground running installed RB199's there was no jump in TBT/T7, you couldn't sense it fire either, the only feel was either the Reheat lighting off with a big roar or the engine going quiet as the Nozzle opened up until the MECU noticed it hadn't lit and closed it again sharpish.

Good eh
Regards
H wie

Wow.....

What a thread! It has consumed many, many hours of my time, and a few groans from the missus (not that aeroplane thing again! ) but it has been so worth it. The level of passion, technical detail and knowledge is both breathtaking and astounding, and would make a thoroughly bloody good book IMO!

Now, from a purely hypothetical POV:

How much would it cost, do you think, that IF EADS really wanted to, using a combination of all the knowhow gained through L'Oiseau Blanc and their current lineup could they produce a 'Concorde NG'? Most importantly, would there be a market for such a beast (at the right price)?

Use something like the A321 fuselage tooling and common flightdeck as a starting point. The Pratt & Whitney PW5000 looks like it could be a mighty fine off the shelf modern Olympus 593 replacement.

There's a start, now thoughts please!! (Please don't just tell me to F**k off and stop being so stupid )

BTW, M2Dude, ChristiaanJ, Exwok, Bellerophon, Brit 312, Landlady et al: Keep up the good work - You have restored my faith in the aviation world! Not everybody involved at the top level is an arrogant a***hole, it seems. Thank you sincerely.

Tom

Landroger
The great thing about the OLY593 was the high specific thrust (in relative terms the Olympus is a tiny, compact design), it's growth potential/high potential mass flow. A bypass engine is not really ideal for supersonic cruise, and given what was available in terms of two-spool turbojets in the 1960s, the Olympus was the obvious choice for both the TSR-2 and Concorde alike. As far as for ships and power stations, well a turbojet is always going to be favourite, as all the gas energy is contained in the jet efflux; this can be efficiently transferred to the load in question by a gearbox coupled to the HP spool.

howiehowie93
Well the 593 did require a primary nozzle to match N1 against N2, bur apart from that she was a study of deceptive simplicity and elegance.
No mate, generally BI-HEX AF.
This really is fascinating stuff Howie, thank you. As I alluded to a few pages back, the primary nozzle on the OLY593 opened in response to the rising P7, kind of 'after the horse has bolted' in a way. To maintain the correct scheduled value of N1, the control system set, via a needle valve, a finite ratio between P7 and P3. As reheat lit as P7 attempted to rise it upset this ratio and the primary nozzle was opened in order to restore the aforementioned ratio. (Nozzle opens, P7 falls). When reheat was cancelled the opposite happened, and the nozzle closed sharply to prevent N1 overspeed.

Tom355UK
Glad you are enjoying our thread, and thank you for your kind words. (But apologies to your good lady wife though ).
Jeepers Tom that is one hell of a question. Assuming there was a market for such a venture (personally not sure right now) I think you are looking at BILLIONS of $, and for this reason alone I think you'd find that a multi-national/continental effort would be required. There is little doubt that technology is not the major barrier here, but economics and political will. (Nice thought though, I do agree).
As far as a powerplant goes, well the PW5000 is a really superb engine, although well down on the thrust requirement for an 'NG' SST. More likely I would have thought would be e development of the Olympus, there was/is still such an enormous amount of potential in this basic design. (But who knows, this is all pure speculation anyway).
And have no fears about posting here Tom, most of us are quite happy to answer away (We've said before that there is no such thing as a stupid question; you are most welcome here ).

DavvaP It really did not matter what airframe we used for the test flight; the sole purpose was just to find out just what effect (if any) the tank liners had on the performance of the fuel system. (The handsome chap who you see on TV most, installing the liners, Mr Marc Morley left BA and now resides in Australia).
I am honoured to say that I was lucky enough to be onboard G-BOAF for that flight from LHR-BZZ and as far as I could tell, the liners had no impact whatsoever. One amusing part of the flight was when we deliberately allowed tank 3 to run dry and see just what the indicated fuel quantity was as #3 engine flamed out (we were subsonic at this point of course). The gauge slowly crept down (in order for the tank to to run dry, the tank 7 & 8 transfer pumps were switched off) and we all watched in eager anticipation/dread....... as the counters reached zero weeeeeee... the engine flamed out. I am being completely honest here, the engine wound down EXACTLY at ZERO indicated contents).
Those 7 aircraft really did look magnificent I know, it was just sad as to the reason they were all lined up there.

Mr.Vortex
Well she was a delta without a tailplane, so the short answer is 'yes', but remember that we used fuel to move the CG backwards and forwards for long term trimming.
OK, this is a little complicated, so bear with me. The intake had a finite limit, in terms of the mass flow that it could deliver to the engine and so an automatic N1 limitation signal was transmitted from the intake 'box' (the AICU) to the engine 'box' (the ECU) full time above Mach 1.6. Now this limitation was referenced against TEMPERATURE compensated N1, ( N1/ \xd6 q) and at normal ISA temperatures this limit was above the 'normal' 101.5% N1 running line. (The lower the temperature, the lower the effective limit became). At ISA -7 the limit now became less than 101.5% N1, and so the demanded value of N1 was reduced to this value. But this limit signal was always there, it's just that at normal temperatures it was effectively ignored by the ECU. If this limitation signal failed for any reason, the AICU would detect this by way of the ramp angle becoming uncomfortably close to it's MINIMUM variable limit (this limit was scheduled as a function of intake local Mach number) and an amber light would illuminate on the associated N1 gauge, along with an amber INTAKE master warning would illuminate (plus an audible 'BONG' from the audio warning system). The only course of action was to manually reduce throttle setting away from the Mach 2 norm of maximum, in order to reduce N2, and consequently N1 and mass flow demand. There was in intake pressure ratio indicator at the top of the intake control panel that would show where the power setting would have to be set to. It was an indirect indication of intake shock geometry.
This manual N1 datum reset control was only used during flight test trials into just how much N1 would have to be controlled/reduced at low temperatures in order to give optimim intake geometry. It had absolutely nothing to do with afterburner/reheat and had no place in the production aircraft as all the research was complete

Best regards to all
Dude

A pot pourri of responses after my Christmas reading!

This actually is interesting in that the n umbers show one of the fundamental features that made the Ol 593 such a good choice. If you look closely at the TO and cruise values you will find that at TO the overall compressor pressure ratio is 13.5 the compressor exit temperature 460 degC and the turbine inlet temperaure is 1152 degC. In cruise the pressure ratio is 10.5, the compressor exit is 565 degC and the TET 1100 degC.

Somebody, I can't find the exact post, was asking whether the elevated cruise total temperatures affected engine life, and here we see why this is so. As Christian said in another posting, when you compress air it gets hotter - from 21 degC to 460 degC at take off and from 127 degC to 565 degC in cruise. A fundamental limit on engine operation is the turbine entry temperature. Not only does it affect the maximum TO thrust you can get but also the continued exposure to cruise TETs has a very big effect on engine fatigue life, and engine manufacturers have shown extremes of ingenuity when developing new materials and ways of cooling the blades to increase allowable TET.

The problem with supersonic operations is that you start from an elevated intake delivery temperature so that when the flow exits the compressor it is already very hot 565 instead of 460 to be exact. But the maximum temperature one can stand for fatigue reasons is limited, therefore the amount of fuel you can pour in must be limited also, and the thrust you can develop per pound of airflow is roughly proportional to the fuel input/temperature rise. To get any sensible cruise thrust then one must squeeze the cruise TET as high as you dare for fatigue reasons but also you need to keep the compression ratio down so that the temperature going into the combustion chambers is as low as you can get away with. This tend to drive engines designed for extended supersonic operations to having a low pressure ratio. This is against the trend in subsonic operations where compression ratios have been steadily increasing along with bypass ratios.


The net result then is that the engine must be designed with a low OPR and must operate with cruise TET much closer to its TO TET value than would be necessary, or indeed desirable, on a subsonic design.



Actually, here, as on some other apparent carry-overs, one should look at the equipment supplier rather than the aircraft manufacturer to trace continuity. Here we have Messier supplying Concorde's gear and Dowty (OK they are now part of Messier) supplying the A330. And having worked on both, I seem to remember that the means of doing the shortening are quite different.

Quote:

Originally Posted by Brit312 The Britannia and now you are talking about the love of my life and yes I do remember the story of the nose and visor selector, but we have forgotten the most obvious. Where do you think they got the idea for the control column from

Yes, they both came out of the Bristol drawing office. One minor anecdote: the 'ramshorn' stick was a novelty to the Concorde flight test crews but they got to like it, or at least put up with it. All went well until it came to the time when Dave Davies, the ARB Chief Test Pilot, came to put his rubber stamp on the aircraft.

Concorde's seats, just like those on your car, could be moved back and fore to get your legs on the pedals and up and down so you could see over the bonnet (sorry, instrument panel). The control column of course stayed in one place, so the relationship of the 'horns' to ones thighs varied with ones height. Andre Turcat was about 6ft 2in, Trubbie and the others of average height. The smallest regular pilot was Jean Franchi at, I suppose, about 5ft 7 or 5ft 8. No problems. But Dave Davies was short like me and he found that he could not get full back stick and full aileron because the ramshorn fouled his thighs.


Consternation! Completely unacceptable! I don't know what arguments they used to convince him it was all OK really, but it got through certification. I would certainly be interested to learn from the pilots in this group as to whether it was ever a problem.

Quote:

Originally Posted by exWok ........which was one reason it was so important to touch down with the wings level - even a very small angle of bank could result in bucket contact as they translated to the reverse position. It was a surprise coming to Concorde to find it was even more restrictive than the 747 in this respect

I can't resist this one!. Has anyone ever noticed/wondered about the tiny bit of the outer elevon that has been chopped off? That was my first real input into the design as a young erk looking at variability of touchdown conditions and coming to the conclusion that if the pilot got into trouble and was trying to pick up a trailing wing with too much AoA as well then he was likely to hit the ground with the downgoing elevon. I persuaded my boss that this was so and we made a small adjustment.
In self defence I am going to plead that this was well before the days of the Type 28 nozzle, so the issue of buckets contacting the ground first never came up!

Quote:

As far as your point about the prototype engines; they were way down on thrust anyway, (even without the 'help' of the silencers), produced more black smoke than a 1930's coal fired power station.

To the point where an American Airline maintainance engineer, watching a prototype taking off and with full benefit of being located strategically for maximum sideline noise, remarked on what he described as 'visible acoustic radiation'

On another occasion, it was reputed that Stanley Hooker, watching a TO in the company of HRH the Duke of Edinburgh, remarked that "You know Sir that that noise represents less energy than it takes to boil an egg". to which he got the reply "Then I must congratulate you Sir Stanley, on producing so much noise for the expenditure of so little energy".

Quote:

Originally Posted by CJ One example : in theory the aircraft did weigh 1.2 % less, so the lift was 1.2 % less and the drag was 1.2 % less, so the fuel consumption was less too, so did Concorde have another 50-odd miles range thrown in 'free' by flying higher and faster than it's low-down subsonic brethren?

There was an effect and in consequence the aircraft performance brochures were formally calculated for north/south flight. Pity really, it would sometimes have been nice to be able to fly guarantee performance demonstrations in the most favourable direction

That's enough for today!

CliveL

Static ports are by no means unique to Concorde; all aeroplanes have them. They measure the air pressure around the aeroplane, and this value is used in various aspects of aircraft instrumentation. In particular, it is used (together with the dynamic pressure value) to display indicated air speed.

Dynamic pressure is what the pitot heads produce - those forward-pointing tubes either under the wings or (as in the case of Concorde) alongside and on the nose which simply measure the pressure of the air generated by the aircraft's forward movement through the air.

By the way - engine bay doors; we open one on OAC for our Technical Tours (not the shorter, 'Classic', tours where there wouldn't be time) so we can show the 593 Olympus and tell our visitors about it. Those doors certainly are heavy!

To complement SSD 's answer, those 'static ports' are located on the fuselage at the location where the local pressure is as near as possibile to the actual outside pressure, which in turn is equivalent to the 'pressure altitude', or, near enough, to the altitude the aircraft is flying at, so it it used to display altitude, and its rate of change is used to calculate and display vertical speed.

When passing Mach 1, the nose shock wave moves rearwards, and passes over the static ports.
As a result, there is a "twitch" on both the altimeter (barely visible) and on the VSI (verical speed indicator, very visible) when exceeding Mach 1.

Any pics, SSD ?
People on another (French) forum were asking about the engines on G-BOAC...
Are they still all in place? Or were any dropped for display outside the aircraft?

CJ

I saw some questions earlier about performance but that's pretty well documented. I was wondering more about for how much longer ( if there had been no retirement )??


Was there a Fatigue Index as other aircraft of the same era \x96 I only know of the Tornado in this respect: a long calculation was made per flight taken of flight duration, G readings, TO weight, Landing weight etc leaving a small number of 0.0000x per flight. Then added to the current FI to give a forecast of life left. If anyone remembers the Tornado 25FI Update Program debacle in the 90's ???


So how was the Concorde's airframe life calculated ?? Flying hours or perhaps pressurisation cycles ? Did a higher altitude effect anything since there would be a higher differential pressure??


On the Engine side, I remember an Olympus Service Bulletin describing the calculation of Fatigue Cycles for the Oly 200:- There was a calculation with several parameters but instruction to disregard below a certain figure, 85% to Max RPM & back was a regarded as a cycle and the LP Turbine Disc was the component with the lowest number of cycles before the need for overhaul.Was this still the case with the 593 ??

We cannot let this thread be consined to the annuls of forgotten history

There must still be a million questions that you always wanted to ask about this wonderfull plane

So here is mine

On Wikipedia they tell us there were 20 Concordes built, 14 production and 6 pre production

Also Wiki tell us there were 67 olympus 593 engines built

Forgive me but this does not seem possible, not enough engines were built to satisfy 'new' engines for 'new' planes on the production line


Does this mean that the 6 pre production a/c donateded some engines to production aircraft so some BA and AF planes flew, even from new, with 'used' engines??

Many thanks

All questions still welcome!

Not quite....

There were two prototypes , 001 and 002 (the ones with the odd porthole visors).
There were two preproduction aircraft: 01, the British one, with a full 'look-through' visor' and 02, the French one, the first one that looked like the production model, with both a 'full' visor, and the 'pointy' tail.
Then there were two 'near-production' aircraft, that were used for certification, route-proving, and suchlike, but that never entered airline service (201 and 202, now best known as 'F-WTSB' and "Delta-Golf").

And yes, then there were 14 production aircraft, that in the end all made it into service with BA and AF.

This is still a slight puzzle.....
The '67' figure probably refers only to the version of the 593 engnes for the production aircraft (4x14=56, plus spares), and not to the earlier versions used for development/testing, for the prototypes, the preprods and the cerification aircraft.

AFAIK , all the production aircraft flew with 'new' engines.

Funnily enough, there's a current discussion on a French Concorde forum on the same subject, trying to figure out not only exactly how many engines were built, but also the "where are they now?".

It would be a nice item to add to the "Concorde Story". We may have to appeal to the RR Historical Trust to open their archives, and tell us exactly how many Olympus 593's were built, and what they can tell us about their history.

CJ

I was recently able - for the first time in about twenty-five years - to visit the London Science Museum. Not only which, I was able to spend the whole day, on my own , with no children dragging me along. As always, the Aviation Gallery occupied a lot of my time there, but I was quite surprised that there is very little about 'our lady', when I should have thought she was sufficiently 'white heat of the technological revolution' to qualify for a whole display to herself?

Going on from remarks about tracing the number of 593s still around, there is one there. Right at the back corner of the Aviation Gallery, on a yellow trolley and next to an RB211. Very little explanation to it and none whatsoever of the astonishing intake/engine/thrust bucket combination.

The only other Concorde exhibit, that I could find, was a beautiful 'cut away' model, standing on a mirror. The model was so detailed and interesting, I took a photograph of it, as I did of the 593, but I find my "PPRuNe Posting Rule" do not allow me to post attachments.

Is it not slightly surprising that there is not more about Concorde there? After all, I was able to revisit an 'old friend' of mine - the original EMIScanner MkI CT scanner from Atkinson Morley's Hospital - that I used to look after back in the day.

Roger.

Well if South Ken want to get rid of that 593, we'll give it a home in our building next to G-BOAC.

Shaggy ,
I doubt South Ken would want to get rid of their 593 (BTW, I'm still curious where that one came from, and what model it is).

I thought Alpha Charlie arrived with all its four engines....
Without wanting to go into the current squabbles, couldn't the museum drop one of the engines for display? They're pretty well invisible from the outside, so taking one out (and replacing it with a couple of plywood panels inside the nacelle, to avoid the horrible hollow-tooth effect we saw on Alpha-Delta in NY), would not do any damage to the display, but it would add another attraction to the museum.

CJ

CJ - AC does indeed have all 4 engines in place and complete. I wouldn't want to drop an engine as that would make her an incomplete aeroplane, and actually you can clearly see the compressors deep inside the intakes during tours, which is nice. She'd look odd with one intake blanked off.

Ideally I'd like a sectioned 593 on display, as there's not a lot to see on the outside of a turbojet engine except the ancilliaries - and you can see those by opening the engine bay doors.

I was curious as well, and hoping somebody with practical experience would post an answer.
The engines were interchangeable among the airframes. Just as well, really, otherwise it would have meant keeping a stock of spare engines for each aircraft !

A more practical issue was that the engines were "handed", so that if a "left-handed" engine failed and you had only "right-handed" engines in stock, you had a problem.....
There is a nice interesting chapter in the Olympus 593 manual on how to convert a "left-handed" engine into a "right-handed" one (it mostly involved moving auxiliaries and other connections from one side to the other), but it was work, and took time. More time than a 'simple' engine change .....

CJ

There used to be one of those hanging from the Foyer roof of the Engineering Department of Leeds University. AFAIR is was motorised and the HP & LP Spools used to rotate at a fraction of an RPM. I think there were internal lights too and/or the spools were painted as well. I think it was also in a Concorde type nacelle. This must have been in the 70's as I used to go to the annual Open Days with my Grandad who worked there.

I can't seem to find any reference to it as to whether it is still there, disposed of or in storeage ??? Perhaps someone has contacts ???

regards
Howie

Hi

I had a look on the eBay link and I question the engine model - the Forward Bearing supports are 5 struts but not the same configuration as the Series 200. I thought the 593 was derived from the 300 Series.

see below a picture of a 593 from Wiki:

File lympus593.JPG - Wikipedia, the free encyclopedia

regards
Howie

I have a query about the thrust of Concorde's engines. The quoted static thrust of the Olympus 593 is 32,000lb, but it has been frequently stated that in supercruise, the majority of the thrust was provided by the intakes. That being so, how much thrust was actually produced overall at Mach 2, and how was this measured (if indeed it ever was)?

Wow, what an amazing thread which I have only recently found.

Congratulations to all for a fascinating read

Although I never got the opportunity to fly on Concorde, I will never forget seeing her fly some charters from Filton in the late 1990's. On one occasion I was stood at the wire fence at the end of runway 27 and watched Concorde taxi directly towards me, do a 360 degree turn and line up for takeoff. Concorde was only around 100ft-150ft away from me when the throttles were opened. Luckily I was holding tightly onto the fence and got a face full of dust as the reheats kicked in! The noise, power and heat I felt from those Olympus engines was phenomenal. She looked stunning as she rotated amongst the heat haze and the slender delta climbed steeply away towards the Bristol Channel. What an aircraft!

My grandfather worked on the Olympus 593 engines at Rolls Royce in Filton, so I will always hold Concorde close to my heart. I have been onboard Foxy at Filton when she was open to the public and I have visited 002 at Yeovilton and 101 at Duxford. I live quite close to Delta Golf at Brooklands and have been onboard her about 4 times now (including a sit in the cockpit) and recently flew the fantastic Concorde simulator with Captain John Eames and First Officer Ian Smith which is a day I will treasure. Opening up the throttles for take-off on 31L at JFK and tackling the checkerboard landing at Kai Tak were experiences I will never forget.

Keep up the great postings everyone!