Aerodynamic Formulas for Helos

[Spaced]

I am looking for the relative formulas for calculating the basic properties of a helicopter rotor.
The reason for this is that I want to make a RC chopper from scratch and would like to work out the basic characteristics before I commit cash and build it.
I have built some planes and gliders before, so I am familiar with basic aero principals, and I am half way through a degree so the math isnt to much of a problem either.
Any sites with the relevant info would be very apreciated, or if some one knows them and wants to put them up here that would be great too.
I know there are some books with it but being fairly broke paying to fly right know, I dont have alot to spare, however any book recomendations would be appreciated. However it needs to be more helicopter design and principals than general aero.
I am currently a student helo pilot, so the extra theory couldnt hurt.

[Dave_Jackson]

Spaced,

If you send an e-mail to [email protected] I'll attach a small DOS program called 'Hover.exe' and its associated files to the reply.

You can run the .exe program and/or read the C-code in the .cpp file.

Hope this helps.

[Spaced]

Dave, I have sent you an email could you let me know if you havent received it.

[Thomas coupling]

Mmm, your handle was well chosen, methinks:suspect:

[Spaced]

:confused: :confused: :confused:
Must be cause Im not sure I understand.

[idle stop]

There are no formulas, but there may be formulae!
Putting aside such a pedantic comment, to be more helpful I recall that Mr Reynolds and his Numbers may pose you problems scaling down from real size to models.
Good luck with your project.

[Genghis the Engineer]

Back when I was learning Helicopter aerodynamics at University there were various books that were invaluable.

My favourite at the time was a big silver tome by Ray Prouty, the name of which escapes me (but wasn't helicopter aerodynamics, which is his non-formulae book).

Subsequently I converted my favours to "Fundamentals of Helicopter Flight" by Simon Newman, which I'd strongly recommend for the basic formulae of helicopter design (or, surreally, windmill design, which is the last chapter of the book). You can buy it from Amazon or a good university bookshop (good here is defined as a university which not only offers aeronautical engineering courses, but teaches helicopter design as well - this probably means Southampton or Glasgow).


If you find yourself buying an American textbook, a word of warning. American helicopter aerodynamicists arrive at their coefficients by dividing by rho-V-squared, whilst British helicopter aerodyamicists (and fixed wing aerodynamicists everywhere) divide by half-rho-V-squared. So, the coefficients for helicopter performance and stability in American helicopter textbooks are (probably) always half the value of the same coefficients in anybody elses books. This can lead you astray if you aren't expecting it.

G

[Spaced]

me Spel , good no? nExt grama u ficks Me on good!

Sorry didnt realise I was on JH.

Thomas coupling,
I dont want to scale something down, I want to see if a couple of my ideas work in reality, and I am aware of what a pain in the but Mr Reynolds can be.

Genghis the Engineer,
I wasnt aware of the difference in the co-efficients. All the work I have done uses 1/2*rho*v^2, why the difference?

Thanx for the replies.

[Genghis the Engineer]

Not the foggiest old boy, I just know that it's there and one should be careful which system is in use when using somebody else's formulae for helicopter aerodynamics.

G