Aerodyn Design Forum

Dear Mr. Duffy,

I'm a senior mechanical engineering student at Middle East Technical University. I'm designing a wind mill for my graduation project. I've got your excel file which I believe is a very good work. However, I have many questions about the file. For example for the blade element momentum theory what does the parameters theta_tip, root chord, tip chord and M_tip mean?

We could not use and simply understand the file. (we couldn't see how the solver files programming occurs. And the theorotical knowledge.) It is very important for our group project. If you can help us with this file we would be more than happy.

Cankuss,

 Have you gotten the code to run?  If not have you tried following the insturctions I posted on the Analysis page?  If you still can't get it to run, let me know what error you are getting?

Theta_tip = is the twist defined at the tip.  This is only valid if you are using 'ideal twist' (cell 'H25' = 0)
Root Chord = Is the chord at the root of the blade
M_tip=tip mach number (this is automaitcally calculated based on RPM and Radius of Propeller

If you are using this for a windturbine, the equations need to be modified.  Since you are no extracting energy as opposed to expending energy.  I have yet to modify the sheet for a windturbine.  But I do plan to, sometime next year.  This will probably not help you now, but i do recommend a good refrence in which you can use to help make ur own spreadsheet based on following the simiple equations laid out in this text: http://books.google.com/books?id=nMV-TkaX-9cC&pg=PR1&lpg=PR1&dq=helicopter+design+leishman+3rd+edition&source=web&ots=CngUleWL7u&sig=smiLz4HkSWydStcly6HL3bq7bX4#PPP1,M1

"helicopter design leishman 3rd edition" - has a windturbine section. Chapter 11, or 13.