BFTO
Veteran Member
Joined: February 2016
Posts: 128 
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Post by BFTO on Jul 1, 2018 17:01:34 GMT -5
Remember to fit a drain at the lowest point  |
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Post by Johansson on Jul 1, 2018 23:15:08 GMT -5
Second that, you wouldn´t want the combustor to fill up with fuel from a leaking valve or whatnot and get a runaway start.
We´ve tried this a couple of times with our old jet kick when fuel siphoned slowly into the flame tube, I had to choke the engine with the leaf blower to avoid a disaster...
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Post by slittlewing on Jul 2, 2018 14:08:56 GMT -5
Hopefully already covered! I designed in a couple of bsp blanks one of which will be at the lowest point and drilled a small hole through the FT to it: [URL=http://s72.photobucke t.com/user/slittlewing/media/jet%20sledge/CDC7C7D8-9CF9-4612-AAED-75363775DA34.jpg.html]  [/URL]  Last time I tried petrol as wet fuel but I now understand this was a newbie mistake, should I go for kerosene (can’t buy locally so eBay I guess) or a diesel petrol mix for the first startup with new combustor? |
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Post by Johansson on Jul 2, 2018 14:41:09 GMT -5
Try straight truck diesel first, just stay clear of the bio diesel crap they sell at the gas station since it won´t burn properly.
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Post by slittlewing on Jul 8, 2018 15:55:02 GMT -5
A bit more progress, I managed to tack the tailpipe together this weekend with the help of my neighbour to hold the cone seams together. The bike is now looking as I envisaged!!    Big thanks to Andy for the tailpipe/AB info!! If this works as well, obviously I’m expecting it to glow red or white hot but I can’t go lower or it will hit the tyre. Will have to insulate things or remake the panels/seat in carbon! A friend and professional motorsport fabricator is going to TIG the tailpipe and purge it, as I don’t trust my own welding ability for such a thermally stressed part. I also started work on the swing arm today. I decided to extend it 6” both to help with tyre clearance, and because it might look good. It may also offer me the chance to mount the battery on the swing arm itself. The extensions are tacked on but I ran out of welding gas. I also cad’d the shock mounts wrong before laser cutting but have a temporary fix!   Sadly whilst the bike was not well supported without seingsrm, the cable ties broke and it fell off the jig. Luckily my Bosch lawnmower took its fall and no damage was sustained to anything!! I hope to have the bike on it’s wheels before the end of next week... |
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Post by Johansson on Jul 8, 2018 23:00:07 GMT -5
Make a heat shield with two thin polished stainless sheets riveted together with a fire blanket inbetween, that will direct much heat away from the seat without having to insulate the entire afterburner which will overheat the AB walls.
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Post by slittlewing on Jul 18, 2018 11:13:04 GMT -5
Yeah I have a plan along those lines (Plan A is single skin with adhesive insulation and going to try 3M reflective gold foil facing the AB), Worst case I could make a second skin around the AB pipe and bleed off some compressor air into it!?
Another random question.. is it possible to burn other oils instead of Kero/Diesel (e.g. actual Automotive Engine Oil or Gearbox Oil)... reason for asking is I may be able to get a decent quantity for nothing and at 2 litres a minute consumption it would be worthwhile!
Many thanks,
Scott
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Post by Johansson on Jul 18, 2018 15:47:13 GMT -5
I wouldnt bother, a crude oil mix will only clog up the nozzles and the cost of fuel is the least of all concerns when building gas turbines.
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jeffreyguy
Junior Member
Joined: June 2018
Posts: 51
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Post by jeffreyguy on Jul 18, 2018 20:00:01 GMT -5
I wouldn't pass it up though for free, you'll find something to use it for. I run my diesel truck on the used stuff, filtered properly of course
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Post by slittlewing on Jul 19, 2018 6:00:10 GMT -5
Hmmm it is tempting (its brand new and unused so no filtering needed), thought it may thin down with some petrol after reading John's post about petrol diesel mixing! Just wasn't sure about combustion quality/suitability!!
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CH3NO2
Senior Member
Joined: March 2017
Posts: 455
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Post by CH3NO2 on Jul 19, 2018 15:30:58 GMT -5
If the crude oil in your area smells anything like what I am familiar with, running your turbine on it would smell awesome. I love the smell of crude oil.
However, when you are finished, be ready to clean out a bunch of coke, crud and tar in the turbine. Crude burns really dirty.
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Post by slittlewing on Jul 22, 2018 11:18:49 GMT -5
Haha ok thanks for the advice, I may get a couple of 20L barrels and mix with petrol at a later date, I’ll do the initial testing with kero though. I have been slowly but surely getting on with the construction, since my last update I have finished welding the swing arm extensions, sorted the suspension pickups, had bends made and welded them to make lower frame rails, made the AB fuel injection loop (thanks again andym), and had the wheels refurbed and slicks fitted. The bike is now standing on its wheels and this week the tailpipe should be getting professionally tig welded together.... Not long now until test fire up!! I have made use of a 2.2L steel welding gas bottle which will be a new oil tank, which also serves as a structural member and lateral engine mount.       |
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jetric
Veteran Member
Joined: December 2014
Posts: 147
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Post by jetric on Jul 23, 2018 15:18:05 GMT -5
Hi Scott, Its nice to see people are still making good use of my afterburner design, It took me four years of R&D and some seriously annoyed neighbors ( due to test runs ) and many litres of kerosene in order to finalize that design into a reliable afterburner back in 2004!!! Did you scale down the dimensions from my plans that Andy sent you to suit your compressor inducer size? Richard S. Haha ok thanks for the advice, I may get a couple of 20L barrels and mix with petrol at a later date, I’ll do the initial testing with kero though. I have been slowly but surely getting on with the construction, since my last update I have finished welding the swing arm extensions, sorted the suspension pickups, had bends made and welded them to make lower frame rails, made the AB fuel injection loop (thanks again andym), and had the wheels refurbed and slicks fitted. The bike is now standing on its wheels and this week the tailpipe should be getting professionally tig welded together.... Not long now until test fire up!! I have made use of a 2.2L steel welding gas bottle which will be a new oil tank, which also serves as a structural member and lateral engine mount.
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Deleted
Joined: January 1970
Posts: 0
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Post by Deleted on Jul 24, 2018 3:28:40 GMT -5
Looking real good..... look forward to seeing it run
All the best
Andy
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Post by slittlewing on Jul 24, 2018 4:03:26 GMT -5
Hi Scott, Its nice to see people are still making good use of my afterburner design, It took me four years of R&D and some seriously annoyed neighbors ( due to test runs ) and many litres of kerosene in order to finalize that design into a reliable afterburner back in 2004!!! Did you scale down the dimensions from my plans that Andy sent you to suit your compressor inducer size? Richard S. I must thank you then Richard, its an excellent design - it seems obvious when you look at it now that the rapid change in x-section provides a stationary swirl zone/flame holder, and the spraying of fuel directly into the turbine wheel to atomise it is ingenious... but I would never have thought to do either of those things from a blank sheet design!! I did scale it down (the diagram was for 3" and mine is 2.5" so all dimensions are about 5/6 size). I'm hoping it works as well as it has on the jet karts!! |
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