Forum
Important Notice for New User Registrations
To combat an increasing number of spam and bot registrations, we now manually approve all new user registrations. While this may cause a delay until your account is approved, this step is essential to ensure the quality and security of this forum.
To help us verify your registration as legitimate, please use a clear name as user name or an official email address (such as a work, university, or similar address). If you’re concerned that we may not recognize your registration as non-spam, feel free to email us at with a request to approve your username.
Optimize blade twist angle distribution
Hello all! I encountered this problem when optimizing the twist angle distribution using the optimal L/D ratio after building the blade model: the optimized twist angle is mostly negative and large (about -10° to -20°), I would like to know why this happens and how to solve this problem. Here are the steps I took to build the model. Thanks for your help!
Uploaded files:- You need to login to have access to uploads.
Here are the detail photos. Thanks again.
Uploaded files:- You need to login to have access to uploads.
Hi Zihan,
when optmizing the twist, the optimization algorithm optimizes automatically for the optimum Glide ratio. Since you have added +6.4 to the Opt Lift/Drag dialog, the optmization is carried out so that the AoA at a TSR of 7 is at the optimum glide ratio +6.4 degrees. If you set the 6.4 to zero the twist distribution should result in what you would expect.
BR,
David
Hi David,
First of all, thank you very much for your answer! Following this method I successfully optimized most of the airfoil twist angles. However, there are still some airfoils with negative twist angles and large values, such as NACA0018, and there are cases where two different airfoils have the same twist angle after optimization, such as NACA4421 and NACA4424, which makes me confused. May I ask what is the reason for this questions? All operations for building the model are the same as before. Thanks again for your help!
BR,
Zihan Wei
Uploaded files:- You need to login to have access to uploads.
Hi Zihan,
both airfoils have their optimum glide ratio at 7° AoA. Thats why the optimal twist distribution is exactly the same!
BR,
David
Thanks for your reply!
Sincerely,
Zihan Wei
