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Post by racket on Mar 20, 2012 22:13:31 GMT -5
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Post by turbochris on Mar 21, 2012 16:30:55 GMT -5
is that an air starter w a combustor? Might make a nice free turbine for one of those ST 50 turbochargers. any clue as to how much air/fuel/horsepower we're looking at WOT?
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wolfdragon
Senior Member
Joined: April 2011
Posts: 287
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Post by wolfdragon on Mar 21, 2012 16:43:19 GMT -5
only thing I don't like about the auction listing for those air starters is that they are sealed, and I have no clue what a fair offer is... let alone if I am winning...
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Post by racket on Mar 21, 2012 20:12:45 GMT -5
Hi Chris
Heres some rough info from one of my texts ...........the Sundstrand had a cartridge as well as air for starting, the cartridge produced gases at 1200psi at 2,000 F for 15 seconds ,with 600 ft lbs output .
They're a rather complex unit with "air brake" to limit overspeeding at ~67,000 rpm , it looks like they had a ~15:1 redux inside for a ~4,000 rpm output .600 ft lbs at 4,000 rpm =450 hp .
One of the Yahoo DIY members used one for a freepower on a kart , the "air brake" ( centrif comp wheel) needs removing and some other mods made , there should be info in the DIY Photos section .................I remember doing a fair bit of PM'ing on the build :-)
Cheers
John
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Post by racket on Mar 21, 2012 20:15:39 GMT -5
Hi Wolf
As the cartridge charges aren't available I doubt the starters will be all that expensive to purchase as they can't be turned into a gas turbine or used for anything much else , except maybe a DIY freepower :-)
Cheers
John
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wolfdragon
Senior Member
Joined: April 2011
Posts: 287
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Post by wolfdragon on Mar 21, 2012 20:28:08 GMT -5
It's not the first time I have seen these go out for auction, and the wife says no more "eccentric" purchases until after the house is done, so I can wait will july...
Would be interesting to know what they do go for...
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Post by racket on Mar 21, 2012 21:54:53 GMT -5
Hi Wolf
LOL............yep , better to not upset the wife :-)
If my memory serves me correctly, there were problems getting the modified DIY freepower flow matched correctly to the gas producer , I'll have a look around to see what info I can find
Cheers
John
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Post by racket on Mar 21, 2012 22:22:09 GMT -5
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Eben
New Member
Joined: September 2010
Posts: 6
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Post by Eben on Apr 20, 2012 21:36:27 GMT -5
Good evening Ladies and Gentlemen
I hope you are all are well
Please accept my apologies for interjecting here but I do not follow or post much as a result of professional obligations. I do however (hopefully) share something useful now-and-again.
Mr. Racket’s memory is obviously still impeccable… as I cannot fault it even using the latest search engines, which it waaaaaay more than I can say for most political leaders today. What can I say, don’t elect the man because he is too reliable…
Anyway, I did have the opportunity to disassemble one of these units in the past and have some information that may be of some value to any prospective users.
Flow Area’s are not as large as some projected numbers, they are in fact, more restrictive compared to some assumptions.
When I was younger I took the time to disassemble and document some measurements (relatively accurate in millimeters)
Single nozzle area was 4,4mm x 12.5mm conn to large round inlet (so work it out)
There are 28 nozzles (rectangular shaped) + 4x round (elliptical) + 1x Dump (Don’t fret,… unless you are pushing 1000++ PSI though small round flange) Racket already explained what this was for in past posts (not necessarily here).
So unless you are up to pushing the boundaries, there is a limited flow area for our homemade DIY use.
Maybe Mr. Racket can figure it out… I would wager… (and since this is his thread and all)
Having trouble uploading image of nozzles...
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Post by turbochris on Apr 22, 2012 8:58:38 GMT -5
Welcome! Don't apologize, tell us more!
I figured the thing would need some pressure, well, that steam rocket we talked about... free turbine steam rocket? Then there's that peroxide Ernie has......
I would vote for Racket over obama any day.
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Eben
New Member
Joined: September 2010
Posts: 6
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Post by Eben on Apr 24, 2012 18:54:35 GMT -5
Good evening I vote for Racket also... Again I need to apologize since I seem to continue to experience difficulty uploading images of the nozzle assembly on the Sundstrand. I was however able to add it to the DIYGasTurbines site in the “photo’s album” in the Sundstrand folder if anyone would like to drag them over from: groups.yahoo.com/group/DIYGasTurbines/photos/album/1289038097/pic/listThe large round inlet (fed by pressurized air, e.g. from APU) is ported to 28x diverging nozzles which are 4,4mm x 12.5mm each. The small round inlet flange (fed by as solid propellant cartridge, e.g. cordite) is ported to the 4x Con-Di (elliptical looking as result of angle) nozzles. The larger rectangular opening (not a nozzle) is the dump port, just in case the cartridge goes into “over pressure” at which point a simple “spring and poppet” relief valve opens and “dumps” the excess at relatively low velocity. Over-engineered especially for the military, as one would expect,... but not the first one of us would complain about the added safety. Eben |
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Post by racket on Apr 24, 2012 23:51:48 GMT -5
Hi Eben
Nice pics ............thanks for that, worth a thousand words :-)
So we have a throat area of 2.38 square inches for the NGV , thats not a lot of area .
What diameter is the turbine wheel ??
Scaling off the pics , maybe 180 mm ??
Cheers
John
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Eben
New Member
Joined: September 2010
Posts: 6
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Post by Eben on Apr 26, 2012 19:48:12 GMT -5
Hello John
Yea the NGV area is a little tight for a DIY project and will limit turbo size to the "small" (under 2 inch compressor inducer) range. This explained why Mr. Steel was having so much trouble with heat while working on his project but he stuck to it and was eventually able to get his ±2 inch inducered turbo to successfully feed through it.
Wow you could guestimate the dimensions that closely from the photograph only?? ...... Hmm...... Now we know whom to send to take a few "pics"in order to "scale" from in the event that we may be in need some reverse engineering. OD is 179mm and the diameter at the root of the blades measures 146mm.
Ciao
Eben
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Post by racket on Apr 27, 2012 0:13:00 GMT -5
Hi Eben
Good pics make it a dream to scale off :-)
Mmm, so the blades are longer at ~16.5mm than the NGV throats at ~12.5 mm ,..... supersonic expansion ?? ....................the turb blades are impulse blades so not expecting any pressure drop thru them , and at 67,000 rpm those 179mm tips are travelling at ~2,000 ft/sec so will need air/gases travelling pretty quick to keep up .
So any potential gas producer will need to be running a jet nozzle no bigger than that 2.38 sq in or a 1.75 " dia jetnozzle if it wants to be hooked up to these starter units , so a mass flow of ~0.5 - 0.6 lbs/sec ....................your 2" inducered turbo with a potential horsepower output of probably 30 hp .
Thanks again
Cheers
John
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Post by turbochris on May 18, 2012 7:13:06 GMT -5
i just won one of those starters $200 watch what happens next! high test pperoxide or steam........
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