Dear Ahmed,

I am not sure understanding your question but if you want calculating the chord, you may look on our attached paper (even if it is tidal turbine, the equations origin as the same as for wind turbine). You may look on the reference section for additional informations.

Regards,

Mohamed

Thanks sir, I mean that the airfoil has many cross sections and the chord I think it has many lengths, so what is the chord value that I have to use?

The answer is in the attached paper. In fact, you have a chord law (Fig. 11c). The chord will therefore depend on the use of the turbine (low drag, ....).

Thanks sir !

Dear Ahmed: The chord length is included in the design methodology of the HAWT rotor. It depends on the tip speed ratio, the flow geometry and the lift and drag coefficient. Basically; the bade is divided in several segments and the chord length is to be calculated at each segments. many books and research articles provide a comprehensive design methodology. I recommend you to read the following paper

" Optimal Performance of Horizontal Axis Wind Turbine for Low Wind Speed Regime"

Regards

   .

Thank you sir.

http://thescipub.com/PDF/erjsp.2013.1.7.pdf

http://dergipark.gov.tr/download/article-file/148237

http://www2.tku.edu.tw/~tkjse/16-4/02-ME10121_875.pdf