implementation into simple BEM Code


I am writing a BEM code implementing the solution algorithm presented in A simple solution method for the blade element momentum equations with guaranteed convergence by A. Ning ( ). I am using the module to extrapolate the airfoil performance out to ±180 degrees. My question comes down to when to estimate airfoil performance. Do I estimate airfoil performance for each section of the blade, or just one time at the mean radius and chord? In Seligs description of the technique used for, it outlines the process, but doesn’t describe how to use it in practice. Both seem like reasonable choices, but I am certain that one is accepted practice. Thank you for your guidance in this matter.

Best Regards,

Logan Unser
Tennessee Tech University

Dear Logan,

I’m sorry, but I’m not really sure I understand your question or what you mean by “airfoil performance”.

Are you asking at what stations along the blade should you apply the 3D rotational augmentation (Du an Selig) model? The 3D rotational augmentation will have the largest effect for inboard airfoils, but may have some non-negligible effect for outboard airfoils.

Best regards,

dear sir

where can i find the link to download airfoilprep and aerodyn ??

Dear Nacer,

The python version of AirfoilPrep ( is available in the WISDEM organization on github:

The newest version of AeroDyn (v15) is included with OpenFAST, also on github:

Best regards,