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Post by stoffe64 on Mar 24, 2014 2:26:30 GMT -5
yeahh, i second...major bummer.....get well my aussie friend, i hope you are ok too!
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Post by racket on Mar 24, 2014 3:12:01 GMT -5
Hi Anders/Stephan
Yep , I'm OK .............getting old ain't for wimps.
LOL ..........I've found it interesting how our bodies urine output varies throughout the day , tomorrow I'll get the measuring cylinder out and do an input vs output vs time of day chart to workout kidney activity ..........heh heh , you know how I love "numbers" ;-)
Cheers John
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Deleted
Joined: January 1970
Posts: 0
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Post by Deleted on Mar 24, 2014 6:35:07 GMT -5
Hi John
hope all is better soon,
I hope to be back there first weekend of May.... so have a little time for some rolling testing, also get other jobs sorted and boxed up
thanks
Andy
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cursorkeys
Veteran Member
Proper engines use the Brayton cycle
Joined: July 2012
Posts: 108
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Post by cursorkeys on Mar 24, 2014 7:45:38 GMT -5
Hi Anders/Stephan Yep , I'm OK .............getting old ain't for wimps. LOL ..........I've found it interesting how our bodies urine output varies throughout the day , tomorrow I'll get the measuring cylinder out and do an input vs output vs time of day chart to workout kidney activity ..........heh heh , you know how I love "numbers" ;-) Cheers John Well solid figures are important, you don't want to stray too close to the choke or surge lines Seriously, sorry to hear about your problems and I hope everything gets resolved ok! Sucks that the bike misbehaved as well Andy. Good test of your safety systems though and it does indeed look badass on the track. Can't wait to see it go
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Post by racket on Mar 24, 2014 16:43:44 GMT -5
Hi Andy
A few weeks of testing will soon get those teething problems sorted :-)
Hopefully I'll be up and going on Thursday .................this catheter has certainly increased my A/R and got me well away from the surge line with its dangerous intermittent flow rates ;-)
Cheers John
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Post by racket on Mar 24, 2014 19:20:55 GMT -5
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gidge348
Senior Member
Joined: September 2010
Posts: 426
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Post by gidge348 on Mar 24, 2014 21:24:00 GMT -5
Yep, getting old sucks.......... but the other option is not so good either Had one of those a few years ago... putting it in is bad enough, wait till they take it out... I think that part of the body is strictly an exit nothing good comes from going the other way... Last week I had an angiogram (another good thing to look forward to) now everything from my waist to almost my knees is black & blue. Getting old is fun Cheers Ian...
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Post by racket on Mar 24, 2014 22:24:18 GMT -5
Hi Ian
LOL .......its no wonder we try and distract ourselves by playing with turbines :-)
Cheers John
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jettoymaker
Junior Member
Joined: September 2010
Posts: 55
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Post by jettoymaker on Mar 25, 2014 0:16:12 GMT -5
Hi John/Andy, Why does it always have to be the things we love to use the most that get taken away from us first. LOL Been there done that Welcome to the "other" very exclusive club Andy...the 'just about to get it all going when...!!' club. LOL John and I have been there so many times we are almost getting used to it. Almost I'm using Life4 batteries as well but although they give a nice extra beginning, they die in the arse reasonably quickly and once they hit 8 volts, they can die literally. I have a second deep cycle battery onboard for my current tests just to get me across the twenty minutes line. I also know about the higher power output of the Life4 batteries affecting the other electrical components too, as they vaporised my first couple of starter controllers. They hit the first one so hard they welded a circuit bridge amongst the zenner diodes as the starter kept running for that run even after the hugh release of the magic blue smoke. Been getting a lot of high temps on B1, how have yours been? Wont be long now. Regards, Andrew
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Deleted
Joined: January 1970
Posts: 0
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Post by Deleted on Mar 25, 2014 14:06:21 GMT -5
Hi Andrew
yep.... the lipo batteries are good, but can drop off a cliff..... think I got problem sorted, test run at weekend :-) think I will get five mins running which is all I need.
Temps seem to be ok, but will be keeping an eye on them when I do some launch testing,
At the moment the plan is to be back on track for 3rd May
Why do you think you temps are up....
All best Andy
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Post by racket on Mar 25, 2014 19:18:51 GMT -5
Hi Andy The 4th stage C20 turbine wheel has relatively "flat" blade section at the tips as well as an acute angle out of ~20 degrees , theres some pics of the wheel on Anders build thread ...... jetandturbineowners.proboards.com/thread/53/landspeed-bike-diy-gas-turbine?page=6 ...............I feel theres a fair bit of turbulence as the gases from the scroll/NGV , travelling at a fairly high speed suddenly impact the stationary wheel and find they have to turn ~320 degrees to exit thru the wheel blades without the benefit of any curved inlet to the blades . We're hopeful that once the freepower wheel is up to design rpm the temperatures will "stabalise" as the gas angles are "negated" ...........its a velocity triangle thing :-) When the Allison engine is installed in an aircraft , either with prop or rotor blades , once the gas producer starts to spoolup the freepower starts to turn and those gas "turning" angles are reduced , both the prop and/or rotor blade angles would be at "fine pitch" allowing the freepower to be spinning rather quickly. The data I have in one of my text gives Ground Idle figures for a C20 engine of ..........45 HP max , gas producer rpm 33,000 - 64.8% N1 , output shaft rpm 4,500 - 75% up to 6,300 rpm - 105%, with freepower rpm of between 24,968 and 34,950 75% - 105% N2 .................at 75% of max rpm those freepower "flat blade tips" won't be a problem . Fuel flow rates at Ground Idle is a max of 70 lbs/hour with an interstage duct temp of 427 C plus or minus 38 degrees C The C20 freepower wheel isn't designed for the "stalled" conditions we abuse it with , there could be a requirement for a "wastegate" in the interstage duct to "unload" the gas producer at startup and during stalled freepower conditions , with the wastegate progressively closing once the freepower rpm rise . The Allison wheel isn't ideal for our use but its the nearest thing available , just another of those engineering compromises we have to put up with. Heh heh , thats my theory anyway ;-) Cheers John
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jettoymaker
Junior Member
Joined: September 2010
Posts: 55
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Post by jettoymaker on Mar 27, 2014 2:27:17 GMT -5
Hi Andy, ...what John said LOL I also think that there is an additional problem in the location of the 10/98 in the frame (no other choices for that I'm afraid if we want to run it on the roads) and some of the inrushing air has been disturbed by one thing or another, as I got 100 degrees C more on this last run after trialing a rough inlet/FOD shield that shouldn't have made any additional disturbance, given the reasonably largish area currently around most of the inlet and the fact that the inlet in Frank uses a similar arrangement and a lot less clear space and no bell mouth into the inlet unlike B1. The next test will include a wine bottle inlet shroud to see if that smooths things in. When I get time, I'm going to make a small smoke generator with a capiliary so I can look at where the disturbances are...unless the wine bottle shroud fixes the problem, although when I did a test to atmosphere with the 10/98 in B1 not running through the freepower, it gave an idle temp reading of 520 degrees C, so I'm betting that John has the goods on why.
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Post by turbochris on Mar 27, 2014 11:29:09 GMT -5
use a small SLA battery or at least switch to LiFe batteries. I've been wanting to put a waste gate between N1 and N2 for a while
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Post by racket on Mar 27, 2014 16:46:32 GMT -5
Hi Chris
I'd like to see one of our freepowered machines with a "centrifugal clutch" or preferably a highish rpm stall torque converter , something that allows at least 30% N2 whilst the vehicle is stationary , that'd be a freepower rpm of ~10,000 when using a C20 4th stage wheel, with the ~6:1 reduction box that'd be an ~1,600 rpm stall torque converter.
I haven't had much experience with torque converters but theres one design I've sorta thought about at times , the freepower shaft's pinion gear meshes with the "ring gear" on the torque converter to produce the required reduction , the torque converter would be mounted within the "gear case" with the output shaft extending from the side for the chain's sprocket to mount on.
Even with our ~150 hp outputs the torque converter would probably need to be sized for a 300 hp engine , due to the freepowers torque multiplication ability , even at 30% N2 we'd be expecting a lotta torque and horsepower when the gas producer was cranked to full power .
On a side note ............. one would expect the Y2K turbine bike must experience the same temperature problems with its stalled freepowers , I've been told that there are torque limits on the Allison gearbox when used for aircraft work .............m m m m , I wonder how they're getting around things ?
Cheers John
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Post by turbochris on Mar 28, 2014 10:40:11 GMT -5
I like how you think John, break shit and back it off a 1/4 turn! how about a converter where the amount of fluid in it can be varied?
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