Turbine design for the complete idiot

[cudabean]

How does one go about learning to design gas turbines? I.e. compressors and turbines including fan jets? Looking mainly for books that were helpful. Any hints on the recommended progression? Can you design something on paper that would have a reasonable chance of being succesful at developing an efficient engine, or do you still need to do a lot of post-design experimentation? How does one decide what shape to make each compressor or turbine blade? How does Reynolds number and expected temperature factor in on blade shape and pitch?

cudabean

[Mike Kirney]

I read a book called "Gas Turbine Technology" once that I got at the public library. Although it was way over my head mathematically, it still provided a lot of insight into the design and construction of internal combustion turbines. I'm pretty sure the big engineering firms have turbine technology down-pat by now, so most of your questions could be answered by examining existing machines. Finding specs on common engines is pretty easy. If you can find a disassembled engine and take pictures or something you will get a real head start. I think blade profile is dependent mostly on the density and velocity of the working gas and the desired rotational speed of the turbine wheel. Lighter, slower gas would dictate thicker blades I think, and this in turn would mean slower rpm. Don't forget about blade pitch too! A turbine rotor is really just dozens of little tiny wings on the edge of a disc. The temperatures in your system would determine what sort of materials were used in your machine. Modern turbines have air passages and outlets cast right into the blades to provide cooling and compressor bleed air is used for all sorts of things. The hotter you get, the more gadgets and refinements you will probably need. What are you going to use your jet to do?

[Hank]

Hello- And also what fuels, mike....

C-Bean- Go to the NACA site and get your printer full of paper to deal with the following:

NACA RM E8002
NACA Report 880
NACA RM E51J25 (this one covers Blades)

Greetings From Post-Industrial America
Hank

[paul skinner]

How does one go about learning to design gas turbines? I.e. compressors and turbines including fan jets? Looking mainly for books that were helpful. Any hints on the recommended progression? Can you design something on paper that would have a reasonable chance of being succesful at developing an efficient engine, or do you still need to do a lot of post-design experimentation? How does one decide what shape to make each compressor or turbine blade? How does Reynolds number and expected temperature factor in on blade shape and pitch?

cudabean

[cudabean]

I went to the NACA site and downloaded a bunch of PDFs (99). One question I have is is the state of the turbine builders art all based on 1947-1959 technology? This will keep me busy for a while.

What I'm interested in doing is developing an resonably efficient engine for homebuilt aircraft. A friend of mine just got a CNC machine and is interested in building turbines as well. We will probably build a couple of different engines from plans to get the hang of things. He has purchased plans from MicroJet engineering for the Phoenix 30.3 (http://www.microjeteng.com/)

cudabean

[Arcan3]

How does one go about learning to design gas turbines? I.e. compressors and turbines including fan jets? Looking mainly for books that were helpful. Any hints on the recommended progression? Can you design something on paper that would have a reasonable chance of being succesful at developing an efficient engine, or do you still need to do a lot of post-design experimentation? How does one decide what shape to make each compressor or turbine blade? How does Reynolds number and expected temperature factor in on blade shape and pitch?

cudabean

Read book on mechanical eng... Ventilators and turbo compresors... its a eng way of saying hydraulic and electric turbines... theyre for moving liquids and gasees... but the equations are the same... just a tip... get a very very large physics book first...

ive read the book 3 times... (someones old as heck thesis on turbocompresors,,, mydads book) and im still having trouble grasping some concepts(im an engineer btw...)

mental note... must find dads book on rolls royce turbines...

[Eric]

Pratt and Whitney have a number of good books from the basic stages to more advanced design parameters, Im not sure if they are made widely available to people outside the company though. I would imagine other companies like GE , and Rolls Royce would have similar sets of books.

And as Hank says the math and concepts involved are not for the timid! :)

Eric

[Arcan3]

Pratt and Whitney have a number of good books from the basic stages to more advanced design parameters, Im not sure if they are made widely available to people outside the company though. I would imagine other companies like GE , and Rolls Royce would have similar sets of books.

And as Hank says the math and concepts involved are not for the timid! :)

Eric

Actually what i dont seem to find are the equations of the relation between the compresor and the turbine... i.e. (matching the compresor to the turbine) since i know...

Rpm= 100k - 160k

but with that figure alone u could make a great number of compresors with diferent adiabatic eficiencies...

i have all the calculations to make a single stage axial compresor of any psi... but ... wut psi should i make it? until i know that i cant start drawing the fins of doing any of the math... my books talk extensibly about multiple stages but mostly for power generators... prollywut i need is there but i just cant see it...

[racketmotorman]

Hi
Your axial comp will only be able to produce around a 1.2 :1 pressure ratio per stage , so several stages will be required for even a small engine .
Try getting a copy of Cohen and Rogers , Gas Turbine Theory , written in the 1950- 60's , it has all the info you'll need.
Cheers
John

[Arcan3]

Hi
Your axial comp will only be able to produce around a 1.2 :1 pressure ratio per stage , so several stages will be required for even a small engine .
Try getting a copy of Cohen and Rogers , Gas Turbine Theory , written in the 1950- 60's , it has all the info you'll need.
Cheers
John

ty.. though that migth be a lil hard since ilive in acountry where the currency exchange is restricted... u know somewhere i could find it online or sum?

[racketmotorman]

Hi
Copies sometimes become available on Ebay , or try Amazon.com .
Cheers
John

[Arcan3]

Hi
Copies sometimes become available on Ebay , or try Amazon.com .
Cheers
John

thats not the online i meant :lol: