HELP for my homemade small gas turbine

[andycp]

Hi, I have doubts about my engine, but first of all, I will put some pictures and my last video trying to starting it up with diesel.

Video-> link (I realized that when I cut off the propane, the RPM´s fell off, so I think before that, there was an expanison on the combustion chamber)















So my first doubt  it´s about the balance, because I don´t have the balancing machine, I had to do it with the rocking method and I hope that this it´s enough for the start up. I said that because when I try to start it up,  I feel some vibrations.

The second doubt it´s for the bearings. Until today, all my test were with (custom full complement radial ball bearings) without preload, so I don´t know if that was the problem to have enough RPM.

But now, I have my new angular contact ball bearings, preload spring, aluminium diffuser, etc. I will put more pictures and more about the new version of my turbine soon.

I will appreciate any help.

And sorry for my english 

[racket]

You need to constrict your leafblower outlet so as to force all of its output through the engine , you need pressure going into the engine ..................more starting power required and more fuel , but just enough fuel to keep the turb wheel blades from glowing , a dull red is OK , but nothing hotter .

Hope this helps

[miuge]

What material have you used to build your turbine wheel? Are the blades welded onto the hub?
Since this compressor wheel seems pretty small size it needs a relatively high rpm to operate, which you probably knew, but after zooming into your picture I have my doubts that turbine wheel would survive the design rpm.. Be careful with that and don't stand anywhere close to turbine exit or side of the turbine...

[ripp]

Hi,
check the values and design of the engine again
1. inlet area of the compressor wheel ~ combustion chamber flow area (all holes + sticks) ~ flow area of the turbine wheel in cm²
2. ngv angle ~ 30°, turbine blade ~ 33°
3. check the clearance: compressor wheel 0.1-0.2mm, turbine wheel 0.15-0.2mm
4. before the first attempt to start do a leak test!

build a test arrangement like this picture, so you have an overview of everything and are in the safe area







good luck Ralph

[andycp]

Jun 18, 2023 17:09:55 GMT -5 miuge said:

What material have you used to build your turbine wheel? Are the blades welded onto the hub?
Since this compressor wheel seems pretty small size it needs a relatively high rpm to operate, which you probably knew, but after zooming into your picture I have my doubts that turbine wheel would survive the design rpm.. Be careful with that and don't stand anywhere close to turbine exit or side of the turbine...

Hi, the turbine wheel was made with a 3mm carbon steel plate, so it´s a whole piece.

I made the  blades by hand with my dremel.

My compressor wheel->Inlet diameter: 35mm/ Outlet diameter: 48mm

 "  turbine wheel diameter: 46mm

About the RPM´s: by the moment, my objective it´s only to self sustaining at idle.

[andycp]

Here´s my turbine plans and the new diffuser design if anyone wants to see it.

[andycp]

Small update of my new design

New diffuser and now I have angular contact bearings with 1Kg preload spring.







I just have to finish the new oil system for both bearings and I will do the new test run soon to see if it self sustain or not.

[racket]

All the best with the test run :-)

[andycp]

Hi, I just finished to assembly the turbine and after some test I just realize that I have a problem mixing the propane with diesel on the same line, because when I´m doing the combustion chamber preheating and I open the diesel line, the propane turns off and the diesel doesn´t light up. I don´t know if this is because when I open the diesel line, too much goes in or it´s because I have to put the propane in a different line.

Can someone explain to me this issue please.

[racket]

You need separate manifolds otherwise you'll have problems

[andycp]

Sept 11, 2023 16:36:41 GMT -5 racket said:

You need separate manifolds otherwise you'll have problems

Thanks!