Re: number of rotor blades

I got the formula in the rotorcraft forum. If i remember correctly
it was written by Chuck Beaty
The units is in pounds and feet, thus imperial.
Yes we use the metric system but I was still brought up with the
imperial system so I still think that way.

Regards

Hennie


[EMAIL PROTECTED] wrote in message news:<[EMAIL PROTECTED]>...
> Just guessing, but your formula uses Velocity and his uses RPM.  The
> 2900 is probably due to the conversion of RPM to velocity in Miles Per
> Hour.
> 
> V = (2*R*RPM)/28 (where units are V=Miles Per Hour, R=Feet)
> 
> Also, your formula is apparently using Kg's and M's instead of Feet
> and pounds.  Then again, I may be totally wrong as CAC is from South
> Africa and they use the metric system too. (I know this because I did
> a search for apartments in South Africa and all the square 'footage's
> were in square meters.)
> 
> It would help if somebody would say for sure what the units are.
> 
> Dennis.
> 
> "Cam" <[EMAIL PROTECTED]> wrote:
> 
> > Hi, I was wondering if there was a simplified formula for working out
> > centrifugal force with a constant mass rotor.
> > Unfortunately I can't make sence of it, what is the constant 2900 derived
> > from?
> > When using, F= MV^2/r
> > F= force
> > M= mass
> > V= velocity
> > r= radius
> > By summing each calculation -- say at r=1m, 'X'm/s,M=1Kg
> >                                                           r=2m
> > 'X'm/s,M=2Kg
> > and so on .(the smaller the increments the better)
> > The end result is not even close to the formentioned formula.
> > Where have I gone wrong?
> > 
> > Cheers Cam
> >  (excuse the metric system)
> > 
> > "Hennie" <[EMAIL PROTECTED]> wrote in message
> > news:[EMAIL PROTECTED]
> > > The centrifugal force generated by a rotor blade
> > > is (W*r*rpm^2)/2900 W is the blade weight. r is the distance from
> > > the hub center to the CG of the blade
> > 
> > 
> 
> Dennis Hawkins
> n4mwd AT amsat DOT org (humans know what to do)
> 
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