turbine blade source

Moderator: Mike Everman

redneck
Posts: 94
Joined: Tue Dec 26, 2006 10:32 am

Re: turbine blade source

Post by redneck » Mon Dec 15, 2008 10:36 pm

I would absolutly love to see your take on a single wheel turbine, I call mine the pancake turbine as it will be fat and short like a pancake... if that makes any sence... I have taken almost 5 years to come up with this design.... I would like to think it will work if the math is done right.... no different than any other jet engine. Just get the amount of air going in correct to the proper speed and then with the correct amount of compression and fuel, it will work.... assuming the turbine is effecient enough, and i see no reason why we caint use known figures for all of this to make it even easier. Maybe find out how much air the shrekling takes in per inlet volume, and RPM, design my inlet to that by having the correct pitch on the blades, then by using volume, compress it to the same pressures as the shreckling and use the second compressor stage to aid in this, and then use the same figures for the exducer on the compressor section and as with the CC though I have something special planned with that ;) ( it will be adjustable with the throttle setting ) and make the exhaust turbine have the same efficiency levels, we should have no problem making it work. And with those cooling venturi, turbine overtemp should be no problem, lower egts, they would act as a zero drag augmentor to encrese thrust even more, making this a very efficient jet. Also, as the bearing assembly is so far from any heat, cooling it is no problem, and there should be less surfice contact as well than with a normal gt, making for less bearing drag, add all that up to the fact that this is an extreemly modular engine, and we should have an effecient, light weight, jet with long run times ans the rear turbine will run cooler than usual. this also should be rather easy to build. I think it can be built with a decient dremel tool set ( as that is about all i can afford ) and some home made jigs. this engine is mostly pipe, to include a portion of the bearing assembly, all of the turbine wheel assembly, outer casting, half the inner casting, almost everything except for the nose ( fiberglass molded over cut foam? ) and the exducer section ( i dont know yet as it will be close to some major heat..... but I have almost the entire thing designed down to how to build it, i just done have the numbers or the knowledge of how to get the numbers. Any body wanna help me on getting the math right? Maybe with somebody with some shekling knowledge and a way to calculate blade angles with rpms? We could build this engine, and soon as it is proven, make a book, and try to get money off the design, and turn a small profit? ( wishful thinking i know...) Anyway... I need math help? who here is smart?
hooowee that was loud! do it again!

Mike Everman
Posts: 5007
Joined: Fri Oct 31, 2003 7:25 am
Antipspambot question: 0
Location: santa barbara, CA
Contact:

Re: turbine blade source

Post by Mike Everman » Mon Dec 15, 2008 11:22 pm

Breathe in then let it out slow... ha
I'm certainly not smart enough.
Mike Often wrong, never unsure.
__________________________

fastnova
Posts: 55
Joined: Sat Sep 06, 2008 8:14 pm
Antipspambot question: 0
Location: Sussex

Re: turbine blade source

Post by fastnova » Tue Dec 16, 2008 9:56 pm

I can’t help with the math much as trig and a bit of transposition and that’s me done.

But on the construction/production side of things I’m quite sure I can help. I have quite a range of manual and CNC machines available threw my job.
If it can be designed around manual machines then that would be easier as I would be able to produce parts quicker as I can only use the CNC machines when they are not set up for a job. But that said opportunities to come up every week for a few hours here and there.
If you send me a few sketches of what you want made, materials and a rough idea of the sizes you have in mind I can let you know how easily/quickly I could have them made.
Also, if the parts are made from Ally, 303 or mild steel then we got s**t loads of the stuff in all shapes and sizes up to 250mm dia bar.

Jonathan
I don’t see problems, only opportunities.

redneck
Posts: 94
Joined: Tue Dec 26, 2006 10:32 am

Re: turbine blade source

Post by redneck » Thu Dec 18, 2008 7:34 pm

well, you can be a BIG help because there are a few parts that I have no idea how to make without machining them. I will take you up on your offer to help, with a few parts, just as soon as I feel that I have the proper deminsions. Are your services going to cost much? Cause I aint got much. I will post demensions here on this post of what I need. After all the parts are made, probably by different people in different areas, all the parts can be sent to whoever can build and test it. I am hoping that the parts can be made by several people, whoever is the best at making some parts, like fuel injectors, shaping blades, welding, machining to specific tolerances, and other such things. maybe, with enough people helping we can actually put this engine togeather, get it working and then build and airplane to put it in. It would be awesome if this site could actually start putting out some engines and do some real research and development. Isnt that what this site is here for? We can all help and make some awesome jets. Well, I am going to the redneck lair full of hooters girl calanders, T shirts, sports illustrated swimsuit eddition pinups, and neon beer signs to throw darts at the wall, and study up on how to make this engine.... just gadda get the numbers right and it will work! Later guys!!!!!!!!!!!
hooowee that was loud! do it again!

fastnova
Posts: 55
Joined: Sat Sep 06, 2008 8:14 pm
Antipspambot question: 0
Location: Sussex

Re: turbine blade source

Post by fastnova » Thu Dec 18, 2008 10:22 pm

Well the idea is there. If we could all get together and share our combined knowledge and abilities I’m quite sure we could come up with something quite spectacular.
It’s just a matter of getting enough people together. Plus the more people that get involved the cheaper the project becomes!

Ok, there are a few areas I can help with more than others,
Manual turning/milling/grinding (anything manual): as much as I have time for.
Full 3D CNC milling with 4th axis: opportunities to come up, but only maybe once a month.
CNC turning with powered tooling and Y-axis, again opportunities do arise, but not on a regular basis.
Welding, MIG only and not for least 6 months.

So there you have it, if you need something done that falls into the above I can help.
As for cost, I wouldn’t worry about that too much, it wont cost me anything.

When it comes to the design I would strongly suggest you show it to or consult someone with some machining experience weather that be me or anyone else, I only say this because you may well go and design something that would do the job perfectly only to have the bloke who is gona make it turn round and tell you it cant be made.
At the end of the day this does depend quite a lot on the tools/machines available.
I’m not trying to doubt you designing abilities, I’m just saying that the person who is making the part, can often simplify a design.

Jonathan
I don’t see problems, only opportunities.

oldgene
Posts: 5
Joined: Tue Dec 23, 2008 8:02 pm

Re: turbine blade source

Post by oldgene » Tue Dec 23, 2008 8:37 pm

I'm new to this forum... This is my first post.

I've been interested in jet engines for years and built a few.

Maybe someone has done this already but how about using the compressor stack out of a Turbomolecular pump. http://en.wikipedia.org/wiki/Turbomolecular_pump

They range in size from a couple of inches diameter to 20 inches or so. I have been collecting them for years for such a project, I probably have 1/2 dozen or so of various sizes.
Usually they have 7 to 10 stages with fixed stators between each stage to straighten out the airflow between each stage of blades. They are designed to run at speeds up to 100,000 rpm, depending on the size. The compression ratio is going to be VERY high, which is exactly what you want for a jet!

The price is both the good news and the bad news. The bad news is that new, an 8 inch pump can easily cost $15,000. The good news is that you can find them used for $10 if your a good scrounger. The highest price I ever paid was $70 for one that appears new with all the electronic motor drive circuit.

Mike Everman
Posts: 5007
Joined: Fri Oct 31, 2003 7:25 am
Antipspambot question: 0
Location: santa barbara, CA
Contact:

Re: turbine blade source

Post by Mike Everman » Tue Dec 23, 2008 11:04 pm

Welcome, Gene.
If you read the part in that article about maximum pressure, sounds to me like you'd want to remove most of the lower stages, and then see what's what. Someone would know better than me, but I think you're on to a great source.
Mike Often wrong, never unsure.
__________________________

oldgene
Posts: 5
Joined: Tue Dec 23, 2008 8:02 pm

Re: turbine blade source

Post by oldgene » Tue Dec 23, 2008 11:46 pm

"sounds to me like you'd want to remove most of the lower stages"

No, in the picture in the wiki article, the low pressure wheel is on the top. That would be the input. With each successive stage, down to the bottom stage the effective blade area gets smaller because the inside radius of the blade area gets larger (forming an inverse cone). The pressure each stage is additive from the top (intake) to the bottom. So the air goes in the (say) 5 inch diameter blade at the top, and highly compressed air comes out a (maybe 1 inch) opening at the bottom of the stack to the combuster where fuel is added.

You absolutely want all the compression you can get because it positively effects the efficiency and the maximum thrust of your engine. Commercial turbojets are built this way, and some of them have as many as 20 stages.

There are some units made by Varian that use a tesla stage or stages on the output. In that case, you might want to remove that stage... I got one of those. It's small and I believe it was called a MicroTorr. The input on that stack was about 2 1/2 inches and the high pressure end is about 3/8 inch.

Post Reply