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peter kent
October 27, 2012, 01:22:00 GMT permalink Post: 7488719 |
Concorde intake shocks question
First I would like to agree with others on the priceless content of this Concorde forum. The published books are gems in their own right but always leave more questions than could ever be answered without all your input.
Whilst looking for some engineering background on the intake flow I came across this paper which goes into some detail https://docs.google.com/viewer?a=v&q...70XxfUcy8PWNyw The author says for example "..pressure recovery at Mach2 was 95%, with 1% of the loss attributed to subsonic diffusion,0.5% to the 1st shock,, 0.02% to the 2nd and 3.7% to the 3rd and final oblique shock." I was looking for mention of a normal shock as I always understood that was a prerequisite for finally getting to subsonic. A normal shock is only mentioned in connection with an alternative design with a lengthened forward ramp. So, was there one or not? Or is it just not that simple? Thanks. Subjects: None |
peter kent
October 27, 2012, 15:00:00 GMT permalink Post: 7489435 |
Thanks for the pictures which I will try to absorb.
In the centre picture it looks like the cowl shock is the 3rd oblique shock mentioned in the paper. As you have said, the region below the reversed "D" is subsonic and there appears to be no plane shock as I understand it, so I'm still a bit mystified. Maybe I should give up on this very complex subject. Subjects: None |
peter kent
October 31, 2012, 21:58:00 GMT permalink Post: 7496372 |
593 smoke reduction
ref question from Joliste
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 seeems to have been cured in later engines
rod "Development of Pollution Controls for Rolls-Royce RB211 and Olympus 593 Engines" by A B Wassall. I have picked out stuff relevant to the question: The engines of the day generated smoke in the primary zone and partially consumed it in the rest of the combustor. It was easier to reduce the production than increase the consumption but leaning the primary zone had an adverse effect on relight capability which then needed its own corrective action as was done on the 211. Metal temperatures went up with the leaning (as intimated by Joliste) The 593 did not have the leaning option as it had to maintain an over-rich primary zone at TO to ensure an adequate weak extinction margin when throttled back at completion of supersonic cruise when the combustor had to operate at A/F ratios over 180. In addition to the smoke problem the combustor weight and pressure loss had to be reduced. These other two requirements led to the annular combustor and vaporizers which also reduced the smoke substantially. These three benefits were expected based on Pegasus experience. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Air France Olympus 593 Relight Rolls Royce |
peter kent
October 10, 2013, 00:12:00 GMT permalink Post: 8090941 |
SNECMA reheat
I've always seen it mentioned as SNECMA reheat until the other day..
The ORIGINAL design for the reheat 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. ref heritageconcorde.com Does anyone have any details on the 'joint' development alluded to above? Thanks. Last edited by peter kent; 10th October 2013 at 00:14 . Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Afterburner/Re-heat Rolls Royce |
peter kent
October 17, 2013, 00:57:00 GMT permalink Post: 8102737 |
New Concorde book
Just out ..
CONCORDE - A Designer's Life by Ted Talbot I've just found an earlier pprune post educating me on the author QUOTE]If I may, I would now like to mention the 'some oil lamps and diesel oil' story. This is a true story told to me by Dr Ted Talbot, the father of the Concorde Intake, brilliant aerodynamicist and all round amazing gentleman.[/QUOTE] Can't wait for it to arrive in my mail box. Last edited by peter kent; 17th October 2013 at 01:45 . Reason: clarification Subjects: None |
peter kent
January 07, 2014, 20:20:00 GMT permalink Post: 8252151 |
Jet noise
Were the primary nozzle spade silencers mentioned in this Flight article used on production aircraft?
Also, again in this article, was it a production feature to open the primary nozzle to reduce noise? Thank you. 1972 | 2644 | Flight Archive Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Nozzles |
peter kent
June 27, 2014, 22:19:00 GMT permalink Post: 8540435 |
Ted Talbot's book
Reading for a second time to see what I missed the first time.
On p86 he says 'It followed the idea of multi-vane auxiliary air inlets into history." Anyone know the story on these inlets? Thanks. Subjects: None |
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