# 5 watt radial turbine design - I need conceptual help

1. Jul 29, 2009

### Mike_In_Plano

I'm looking to design a radial turbine to deliver 5 watts from compressed air (60-90psi) at 20,000 to 40,000 RPM. 30% efficiency would be suitable.

I reviewed related patents-got little from them. I also reviewed my college textbooks, but they address incompressible, momentum transfer problems.

Any suggestions on how to approach this sort of problem?

Mike

2. Feb 15, 2010

### apc3161

I could probably help. Still need help?

3. Feb 16, 2010

### Mike_In_Plano

Yes, thank you, APC.

- Mike

4. Feb 17, 2010

### apc3161

Were you looking to just design one for the sake of it, or designing one to actually manufacture?

I ask because that will probably determine whether you should go with a 2D or 3D turbine. Google mit micro turbine for an example of a 2D turbine.

Let me know, I have written code and could easily just give you the necessary dimensions necessary.

5. Feb 17, 2010

### Mike_In_Plano

Thanks APC,

My need is for a turbine / generator to function as part of a system that operates in a harsh electromagnetic environment. My rational is that the power could be supplied via the house compressed air, doing away with the need for electrical interconnects.

I've intended to move the product into low volume production (100-200/yr) and it would be great if I could find a turbine on the shelf for 250-$350, but the best I've found was more than$1K. At this point, I'm not certain whether such cost targets could be met.

As far as the geometry, it would be great to have something easy to machine and assemble. My favorite machine shop doesn't have 5 axis equipment. As to balancing, I could probably build a fixture to strobe it - if needed

I can't express just how appreciative I am that you've taken an interest in this work. It's frustrating to have proceeded so far and be forced to stop over just one item...

Best Wishes,

- Mike

6. Feb 18, 2010

### mfc5200

I'm not familiar with where you can purchase your own micro turbines. You would probably have to make them yourself for the time being.

A cheap low quality solution is to chemically etch stainless steel.

http://www.micromark.com/MICRO-MARK-PRO-ETCH-PHOTO-ETCH-SYSTEM,8346.html [Broken]

to get 2D turbines that look like this

http://www.fas.org/man/dod-101/army/docs/astmp98/figv10.gif

Also, 5 watts is an absurdly small amount of power. Make the turbines is very cheap in this way, but the generators are always the expensive part.

We've used DC brushless motors before that run in reverse from companies such as Faulhaber and Maxon Motor. Although getting appropriate bearings and the shaft link is not as easy as you would think.

Last edited by a moderator: May 4, 2017
7. Feb 21, 2010

### Mike_In_Plano

The etching is a cool concept. I thought machining of laser cutting were the only viable options. I'll still need to get a geometry,

As for a generator, I'm not too worried. I'm a EE that's designed several Brushless controllers, and using them for efficient generators is duck soup. I just need to manage teh bearings and vibration so that it lasts.

Any ideas?

-Mike