report KD 501 about moment coefficient of cambered airfoils made public

[Adriaan Kragten]

Report KD 501 has been made public. The title of this report is: "Determination of the Cm-alfa curves for different positions of the axis of rotation for a 10 %, 5 % and 7.14 % cambered airfoil with an aspect ratio of 5". These characteristics are required if one wants to design a pitch control safety system for a rotor with 7.14 % cambered steel blades. The moment coefficient Cm0.25 for a blade axis lying at 0.25 c from the airfoil nose is rather high and the aerodynamic moment can therefore be used to steer a positive pitch control system which increases the blade angle beta.

More information about pitch control systems is given in public reports KD 437 and KD 622. These reports can be copied for free from my website: www.kdwindturbines.nl at the menu "KD-reports".

[finnsawyer]

     How about answering my challenge to determine how a board gets lift using the theory I gave ten years ago.  (Contained in the Post "THE BETZ LIMIT - AGAIN ").  The Result may surprise you.   

[joestue]

     How about answering my challenge to determine how a board gets lift using the theory I gave ten years ago.  (Contained in the Post "THE BETZ LIMIT - AGAIN ").  The Result may surprise you.   

can you at least link to it?

[Adriaan Kragten]

I didnt react on the first comment because this isn't a reaction on my report and there is no link to that what I should study.

KD 501 is not a theory but it contains a summary of measurements of two different airfoils and the derivation of the moment coefficient around another point than the nose.

[Adriaan Kragten]

I have tried to find the post "THE BETZ LIMIT - AGAIN" by typing this title at "search", but nothing is found. So I can't react on it. But from the title I think that it is a complete different subject as described in my report KD 501.

[finnsawyer]

     I tried searching "The Betz Limit", here.  The post was the 11th hit.  Way it goes, I suppose.