Wanted: Allison C20 3rd stage NGV and turbine wheel

[Johansson]

A german guy (youtube name-marvnero) has asked me in one of my youtube video comment fields for a suitable turbine wheel for his 40kW turboshaft project, and I figured that a 3rd stage C20 turbine wheel and NGV would suit his needs.

Is there anyone who is interested in selling him a set?

Cheers!
/Anders

[racket]

Hi Anders

A second stage set will produce that sort of HP , there often some on Ebay ,check under ............turbine wheel collector

Cheers
John

[Johansson]

Ok, I´ll point him towards the 2nd stage bits then, thanks John!

[pitciblackscotland]

Hi Anders,
I have a C30 2nd stage wheel that he can have for $100 AUD plus shipping. I don't have the NGV for it.

Cheers,
Mark.

[Johansson]

I´ve suggested that he become a member here, so in case he is interested in the 2nd stage wheel you´ll hear from him directly Mark.

[pitciblackscotland]

Yep good idea

Cheers,
Mark.

[marvnero]

Hi Mark,

As I'm using the 2nd stage as my first axial stage and- if my calculations are correct- there won't be a significant amount of drall left after the first radial stage at operation speed, I'd have to fabricate my own stator (or NGV) anyway.
Do you have some dimensions of the rotor? I've got about 1.2 kg/s and an estimated absolute pressure around 1.8 bar after the radial turbine (sadly the computer with the exact calcs isn't working right now).
Do you think that it works with the C30 2nd stage wheel?

Cheers,

Marvin

[racket]

Hi Marvin

Could you please supply some more information on your gas producer .

If you have ~1.2 kgs/sec and 1.8 bar absolute interstage pressure , then you'll have the potential for a great deal more power than 40 Kw , more like 150 Kw .

A third stage wheel is what I used for my turbine bike flowing ~0.8 kgs/s and it produced ~115 HP - 85 Kw on the dyno www.youtube.com/watch?v=CplnY9TG7NE

Cheers
John

[marvnero]

Hi John,
Well...that is waaayyyy more than I calculated!
But I have to admit that I did my calculations with a total pressure ratio of 3:1 to get 77% of polytrope efficiency (I hope thats the right translation) across my compressor and a 1st stage entry Temperature of 700°C to get a worst-case scenario.
How high is the temperature before your 1st stage?

Cheers,
Marvin

[racket]

Hi Marvin

With a quality turbine wheel made from Inco 713C, turbine inlet temperatures of 900C are acceptable , 700 C is very low .

For short duration usage , temperatures for a quality turbocharger wheel can go to 1050 C for 713C and ~850 C for the inferior "diesel" GMR235 material

Have a read here www.epi-eng.com/piston_engine_technology/turbocharger_technology.htm

With a 700 C turb inlet temp and a 3:1 PR you normally won't get a 0.8 bar interstage pressure.

Cheers
John

[pitciblackscotland]

Feb 14, 2017 16:28:28 GMT -5 marvnero said:

Hi Mark,

As I'm using the 2nd stage as my first axial stage and- if my calculations are correct- there won't be a significant amount of drall left after the first radial stage at operation speed, I'd have to fabricate my own stator (or NGV) anyway.
Do you have some dimensions of the rotor? I've got about 1.2 kg/s and an estimated absolute pressure around 1.8 bar after the radial turbine (sadly the computer with the exact calcs isn't working right now).
Do you think that it works with the C30 2nd stage wheel?

Cheers,

Marvin

Hi Marvin,
The OD of the rotor 170 mm and blade length 25 mm John will help you out with your project. There is a flood of Allison turbine parts at the moment,turbine wheels, NGVs, ect,ect not cheap they are asking more than scrap value.

Cheers,
Mark.

[bournaVee]

How much can I get a 3rd stage turbine wheel. I want to use it for my 120pounds output turbojet convertion

[nersut]

I have a 3rd stage turbine wheel for sale on eBay, no: 262946065895

[bournaVee]

alright.. let me check it out

[bournaVee]

hi nersut
the price is quite high