dan
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Joined: October 2017
Posts: 37 
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Post by dan on Oct 11, 2017 23:04:03 GMT -5
Hello everybody. I would like to build a motorcycle powered by a gas turbine. Clearly I have come to the right place. The project is very much a blank sheet of paper at the moment, but I would like to achieve somewhere between 75-150HP, and be able to cram it into a 1200 V-Max frame. (because I like them and have loads of spares) I'm weighing up a few different power-plant options, and would appreciate any input on the following selections… - A rover MK10501 - (Nimrod APU) - This kicks out plenty of power, and I guess that after removing the ‘air start’ compressor, one is left with a gas generator and power turbine in a nice compact unit. I am however a little intimidated by the prospect of gearing down from 47,000 rpm.
- T312 (Tornado APU) - Powerful, small and light turboshaft unit, with decent reduction gearbox. This would provide drive via a simple CVT and multi-plate clutch.
- RR Artouste Mk123. - Not exactly compact, but very reasonably priced - again driving through CVT and clutch.
There selections are from www.jetenginetrader.co.uk which I live pretty close to. Thanks in advance. Dan |
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Post by racket on Oct 12, 2017 3:11:01 GMT -5
Hi Dan A worthwhile challenge :-) Yep , choice of engine would be critical , a bike is the hardest "vehicle" to mount a turbine engine in, they always seem to be the wrong shape and is the reason why its sometimes easier to build an engine that "fits" . Have you checked out Andrews build jetandturbineowners.proboards.com/thread/34/motorcycle-project , same same gas producer as Anders engine , but with a different power turbine orientation and gearbox arrangement . Cheers John |
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dan
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Joined: October 2017
Posts: 37
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Post by dan on Oct 12, 2017 13:06:00 GMT -5
Hi John,
Thank you for the link, that is a fantastically compact build.
Appreciated bikes are always the wrong shape, but I can tweak/cut/stretch as required.
Did you supply the gas producer for this?
what is the going rate for an 4th stage C20 wheel at the minute?
I think a custom gas generator + C20 (whilst certainly the most elegant design), would require a larger time and cost investment than an APU + transmission system. Do you think that is the case?
The main reason I was looking at APU's as a starting point was that it seemed a way to build a turbine Bike on a budget. Not after setting any records.
Thanks a lot.
Dan
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Post by pitciblackscotland on Oct 12, 2017 15:56:26 GMT -5
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Post by racket on Oct 12, 2017 16:15:45 GMT -5
Hi Dan Yes , the gas producer in Andrews bike is my 10/98 engine jetandturbineowners.proboards.com/thread/19/10-98-engine , I also made the freepower/gearbox section, 4th stage wheels on Ebay for a couple of hundred dollars US. An off the shelf APU would be a quicker and "maybe" cheaper alternative , but a lot of APUs are single shaft engines with poor power producing characteristics requiring "special" gearboxes to do them justice. Cheers John |
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dan
Member
Joined: October 2017
Posts: 37
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Post by dan on Oct 12, 2017 17:08:28 GMT -5
Wow John, that is one beautiful engine!
"special" gearboxes fill me with dread.
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dan
Member
Joined: October 2017
Posts: 37
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Post by dan on Oct 12, 2017 17:16:36 GMT -5
Hi mark, I've got a few big tubos in storage. Will get them out and see if there is anything suitable. Pics to follow. Thanks Dan |
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dan
Member
Joined: October 2017
Posts: 37
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Post by dan on Oct 13, 2017 14:30:23 GMT -5
Hi, Don't seem able to upload images - have tried from multiple machines, goes through the motions, but fails to insert image into the post :-( I have dug out a pair of these from my spare room, both new and unused link (hopefully the link works) I don't have any information on them other than the name plate, and the A/R's on the castings. There are 6 more of similar dimensions, but they are all used, and may be damaged Dan |
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Post by racket on Oct 13, 2017 15:45:52 GMT -5
Hi Dan
What are the wheel dimensions ??
Cheers
John
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dan
Member
Joined: October 2017
Posts: 37
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Post by dan on Oct 13, 2017 17:12:03 GMT -5
Hi Dan What are the wheel dimensions ?? Cheers John Hi, Compressor inducer diameter = 70mm, exducer = 94mm Turbine inducer diameter = 82mm, exducer = 75mm Dan |
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Post by racket on Oct 13, 2017 21:25:05 GMT -5
Hi Dan They'd be OK for ~75 HP from a freepower downstream . I've been checking out the Nimrod APU specs and it might be your best bet , don't worry about the 47,000 rpm figure , a freepower turbine turns out 80% of its potential power at 50% rpm , so say 120 HP at 23,500 rpm , a much more manageable rpm to gear down from . Please have a look at what these guys are doing with a similar engine jetandturbineowners.proboards.com/thread/628/spridjet-rover-turbine-powered-lenham Cheers John |
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dan
Member
Joined: October 2017
Posts: 37
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Post by dan on Oct 14, 2017 13:22:14 GMT -5
Hi John.
Lower gearbox speeds sound very promising. Nimrod APU is looking like the way I'm going to go.
Great to see the thread from frankenhealey. Very cool stuff.
I'll get in touch with Mr 'Jet engine trader' and arrange a viewing next week.
I can borrow a borescope, so should be able to give the internals a quick inspection.
Thank you very much for your support and assistance.
Best wishes.
Dan
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Post by racket on Oct 14, 2017 16:54:18 GMT -5
Hi Dan
From what I can gather from reading some of my books , the Nimrod APU is relatively lightweight and uses a Rover 1S/60 compressor wheel for the supply air , they would have needed the highish rpm to get any pressure from it .
Yeh , I think I'd go with it , 20 odd thousand rpm is a manageable rpm to work with ..............I'll do a bit more research :-)
Cheers
John
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Post by racket on Oct 15, 2017 18:42:04 GMT -5
Hi Dan
It might pay to check about "throttleability" of the Nimrod APU , the fueling/combustor is different to the 2S/140 "road" engine that its based upon , the combustor is a cruder "full throttle" APU type setup.
The freepower wheel that powers the current compressor/blower is pretty large so must be running fairly high tip speeds , much higher than what Anders is running with his engine even though both have fairly similar mass flow rates through them , only ~10% difference in flow with Anders being the greater, but possibly ~40% higher tip speeds for the Rover , so plenty of scope to bring that down without a big loss in horsepower .
Cheers
John
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dan
Member
Joined: October 2017
Posts: 37
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Post by dan on Oct 16, 2017 4:55:09 GMT -5
Hi John,
I had assumed "throttleability" would be pretty poor as standard, and the stock fuel delivery system would have to be ditched. My hope was that this could be overcome with fuel pressure management, perhaps even spilling off some air from the compressor to keep flow down at an idle setting.
Since the engine is capable of getting from its ignition condition through to 100%, I also assumed that with some tinkering of fuel/air ratio, it should be possible to get a stable flame at a few points in between for various power settings. Ideally idle, full power, and a couple of settings in between.
Not really sure how to confirm or disprove these assumptions without getting an engine and experimenting.
any suggestions would be gratefully received.
More good news about the free power side. Definitely planning to incorporate a waste-gate system between gas producer and power turbine for use during idle, possibly forming part of an N1 over-speed protection strategy (before fuel cutoff). Perhaps this could be used to overcome any combustor shortcomings.
Thanks again for taking the time to give input.
Dan
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