Frans,
you are absolutely right:
More
> blades is a compromise.
Just one is best = most efficient.
They (Germans) have done that, with a counterbalance of course.
More blades compromise an efficiensy because of ground clearance, noise, tip
speed,
how it look and so,.
Raimo OH-XRT
----- Original Message -----
From: "Frans Veldman" <frans@privatepilots.nl>
Sent: Friday, April 16, 2010 5:11 PM
Subject: Re: Europa-List: Re: 2-blade props
>
> On 04/16/2010 01:41 PM, Gilles Thesee wrote:
>
> > Apart from what Karl said, the number of blades has something to do with
> > the prop *solidity* necessary to transfer power. The aircraft you cite
> > have powerful engines, hence the tendancy to increase the number of blades.
>
> Right. If you increase the amount of power, at some point you have to
> increase the diameter of the prop. If you can't do this (for clearance
> reasons), you will have to revert to adding some more blades. More
> blades is a compromise.
>
> > Our airplane and two-blade prop were designed just a few years ago, and
> > they are quite efficient aerdynamically.
>
> I can't think of ANY reason why more blades would be more efficient. I
> can however think of reasons why less blades is more efficient.
>
> Frans
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