idea for fuel injectio without fuel pump

[adam]

kinda new to the forum and dont really mess with the turbines but instead the valveless pulse jets, but i was wondering if anybody has or can do this to a turbine engine?>> drill a hole or use a hollow shaft for the compressor/turbine rotor and right were the shaft goes in through the combustion chamber section, have very fine hole drilled in a radial pattern or several holes in a radial patern only were the shaft goes through the combustion section and then have fuel injected down the hollow shaft from the front of the compressor into the shaft, so while the shaft spins it produces radial or should i say centrifugal forces that throw the fuel out of the little orifices in the shaft and spray a fine mist right into the combustion chamber maybe some flaps or somthing can be machined into to hollow shaft so that way it can grap and rotate the fuel in it better, as it throws the fuel out from centrifugal forces it should creat suction at the front of the hollow shaft were the fuel is being introduced right?

[Johansson]

It has been done on a drone turbine, I believe it was the Williams WR24, which had a feed pump that led fuel into the hollow shaft where it was subjected to the centrifugal force and ejected at high pressure through holes in the shaft into the combustion chamber.

An interesting way to feed fuel to the engine, but waaaaay to complicated for the average DIY guy since drilling a standard shaft without any clue on how the holes will affect its strenght is pretty stupid. Add the fact that you need a way to control the amount of fuel that goes into the engine, so a feed pump and throttle system is still needed.

I might very well be wrong, but I believe that the main reason for Williams to use a rotory atomiser is to cut down on expensive accessories and weight since the engine is supposed to power drones and is therefore not expected to last very long. The high EGT comfirms that thrust was the main priority rather than endurace when they designed the engine.

//Anders

[Fricke]

kinda new to the forum and dont really mess with the turbines but instead the valveless pulse jets, but i was wondering if anybody has or can do this to a turbine engine?>> drill a hole or use a hollow shaft for the compressor/turbine rotor and right were the shaft goes in through the combustion chamber section, have very fine hole drilled in a radial pattern or several holes in a radial patern only were the shaft goes through the combustion section and then have fuel injected down the hollow shaft from the front of the compressor into the shaft, so while the shaft spins it produces radial or should i say centrifugal forces that throw the fuel out of the little orifices in the shaft and spray a fine mist right into the combustion chamber maybe some flaps or somthing can be machined into to hollow shaft so that way it can grap and rotate the fuel in it better, as it throws the fuel out from centrifugal forces it should creat suction at the front of the hollow shaft were the fuel is being introduced right?

Hi.

Well Several of the Turbomeca and Continetal/Teledyne engines used/use that method of delivering the fuel into the CC. They have a fuelcontrol unit with speedgovenor to control the engine. There is no need to jhave any "flaps" the centrifical force will spread the fuel evenly in the hollow shaft. If I´m not totally wron the Kapms turbine engine have a hollow shaft, atleast it´s hollow between the threaded ends. The only probem is to seal the fuel delivery pipe that is fixed to a shaft that is spinning at 120000 PRM... And you still need a fuelpump to feed the shaft/nozzle...

Do a Google on Turbomeca Marbore and Palas engines to get an idea on how they designed it.

//Fricke

[adam]

here is a cool little pic of the turbine jet i got for only $ 800.00 flat brand new with everything to start included. well this is only a 12lber but is pretty cool, i beleive it is an exact replica of a wren turbine engine and it runs really well and is made of strong materials like the incolnel turbine blades and so on and so on, so if anybody is wanting cheap turbine as there new engine you can contact joe at www.jetjoe.com or just look up jetjoe on a search engine and it should pop up. well just letting you guys no where the cheaper products are for those with low budget, because i looked all over the web and couldnt find a turbine this cheap until i bumped into this guy in person and some rc club.

[adam]

another

[adam]

another pic

[adam]

another

[adam]

another picture

[adam]

last pic

[Irvine.J]

Hey adam, hows that crazy go-kart going? That thing was awesome.

I've seen these, it looks nice, though it has ridiculously poor overhaul times. As a member of RC groups I get the good info on alot of this stuff, it has been the demise of many an extremely expensive aircraft. They tell me turbine failures are quite common in jet joe (theres a reason you pay 800 instead of the normal 3000), so don't stand side on to it lest you catch a piece of fan moving at 500mps. At 65 000 rpm its crazy speed, so play safe, I've seen quite a few just flame out, loose power, or just freaking explode, so make sure you use only oils/parts from the manufacturer. Theres a movie of someone spooling it up in his plane and it detonates and completely severs the plane in half somewhere.

http://www.rcgroups.com/forums/showthre ... 397&page=5
It doesn't have a balancing ring...ohhh dear. Always stand clear.

[adam]

hey well i just been really busy and put a hold on the go kart, i need to get four new wheels for it and every thing will be complete and i will film me driving as fast as i can get it to go, which should be over 60 mph because i got it up to around that speed with four flat tires but the tires are so thick they almost seem as if they are not flat at all, it almost seems like they are tubeless tires , but they sink in towards the middle do to no air pressure so i am hoping to go a little faster when i can find some new wheels and tires. oh yea and by the way, i guess you might be right about jetjoe because i met him in person at a rc club in new mexico and this was the first time i ever seen a micro turbine start up so when he was startin his turbine that was mouted in his jet that he was about to fly i was intersested in the amount of exhaust gas that was flowing out of it so i was standing behind it and after about 20 second or so he spooled it up right as i was standing and looking down into the turbine from the back and the thing just went thwoooooomp and shot out two turbine blades, i was pretty lucky because nothing hit me, he told me that was the first engine to do that and he told me later on that the lube line to the bearings were kinked so it was bearing failure, but i dont know i hope mine doesnt do that, its been running really good so far but i guess ill see how realiable it is in the long run.

[Irvine.J]

Man that sucks! Lucky you got both your eyes, not every day you have to dodge streams of burning metal LOL. Way to dodge the turbine man!

Good stuff about your gokart, I remember the one with you "fangin" down the road propane tank under arm, man that was a cracker. Seemed pretty darn fast
Goodluck!

[adam]

dang i just got done reading threw some of the forum that you post, it seems that a lot of rc people dont like his product, well that sucks, now that makes me want to get rid of it and make my money back, oh and the videos of me riding the gokart that i posted it was kinda slow maybe around 20-25 mph or so.

[Irvine.J]

Well, revenge is a dish best served cold, usually in large blocks of C4 or napalm, extreme prejudice always helps! LOL
No, look I mean it might go pretty swell for a long time, I guess you don't really know, wouldn't stop me from using it though, enjoy it whilst it lasts, chances are you'll never get your money back, and that suits jetjoe just fine.
Just have some fun with it man, i'm sure you'll find 10000000 and 1 cool things to do with it!

[Eric]

Yea down the axis of the engine is actually a lot safer than by the side when it loses a blade.

If i were you I would run that thing in a 6 or 8" diameter section of steel pipe to contain any of the blades that might fly out the side.

Eric