axial turbine design

[techtoast]

hello all, i'm techtoast.

I would like to design and eventually build a small axial turbine jet. I plan on it being between the size of a coffe thermos and a 2 liter pop bottle. I am undecided on the fuel but am open to anything including propane, alcohol, gas (possibly others i can't think of?). I plan on doing this the right way from start to finish. I want to work my way through all the math to figure out exactly what I am doing, and make 3d and CAD mock ups as I go. I suppose I should start by experimenting (mathematically) with the combustion chamber, which takes up about/less than a quarter of the size (if i'm not mistaken), and draw up a chart of provided kinetic energy for all the possible fuels versus the possible target sizes. Then try and work that out as to the turbine and compressor design accounting for aerodynamics and weight versus the required airflow.

Is this the right way to go about it? Where do I look to find the formulas for calculating this? Are there any good books that you can recommend? any help is greatly appreciated and i can't wait to get my calculator going!

[Johansson]

Hi and welcome to the forum!

Are you saying that you are planning to manifacture a gas turbine with an axial compressor wheel, or an axial turbine and radial compressor (turbocharger compressor wheel)?

I really hope that you aren´t going to start your gas turbine career by heading down the axial compressor route, some really really experienced guys have spent several years and a pile of cash and the compressor still doesen´t work nearly as good as a standard radial compressor.

Thomas Kamps book "Model Jet Engines" is an excellent book for understanding and designing your own micro turbine, it also has complete drawings for those who want to make a copy of his engine. Kurt Schreckling is another guy who has written some books on the subject.

Good luck, and keep us updated on your progress!

[techtoast]

Eventually I plan on building one with an axial compressor down the road, but I would like to know how to work out all the math for "bench" testing it before I spend any money on it. In the meantime I think I will heed your advice and stick to designing one with a radial compressor. How would I do the math for this?

And when designing the axial drive turbine, are stators required/recommended?

[racketmotorman]

Hi Techtoast

Purchase this book .......... https://shop.traplet.com/product.aspx?c=183 it has all the info you'll need ,..............its often available on Amazon http://www.amazon.com/s/ref=nb_sb_noss? ... es&x=0&y=0 but why they are more expensive there than from the Publisher I don't know

All the best with the build

Cheers
John

[techtoast]

Thanks for the great reference guys! I'm reading the book now, and am trying to wrap my head around the equations. I will post back if I have any questions about them for clarification if I need to (which I probaby will). I didn't exactly make it to trig, but I'll throw everything I've got at it before I ask.