Learning Forum

[N. M.]

Hello Everyone.
I am attempting to obtain the hysteresis loop for several NACA airfoils, validating the results with those available in the scientific literature.

Despite numerous attempts, I have not been successful in achieving a convincing hysteresis loop, closely resembling the ones presented in reference scientific papers.

I followed the steps:

1. Imported the NACA geometry (acquired from Airfoil Tools) into the Geometry module.
2. Created the domain, as illustrated in Figure 1. The distance between the chord quarter and the vertical wall (outlet) is approximately 10 times the chord length, while the height of the domain is about 5 times the chord length.
3. Generated the mesh, as depicted in Figure 2, with additional detail shown in Figure 3.
4. Defined named selections to be utilized in Fluent for setting boundary conditions (Top, Bottom, and curved walls set as input; vertical wall set as outlet; and the airfoil).
5. Configured the Fluent simulation with the following settings: k-omega model, transient simulation, specified inlet velocity, dynamic mesh (ambient as deformable, and the airfoil as a rigid body rotating around the chord quarter using a User-Defined Function), reference values set with area = chord, Report Definitions to compute cl and cd, residuals set to 1e-6, Initialization (Hybrid initialization), and ran the calculation with a time step of 0.0005 s.

 

Has anyone encountered a similar problem and found a solution? Did I miss any crucial steps in the process?

Thank you ????

 

 

 

[Essence]

Hello,

You are simulating the magnetic field around the aerofoil. Is this what you meant by hysteresis loop? You can try the steps as provided in the Ansys guide and tutorials. We also have some best practices to the same.

https://ansyshelp.ansys.com/Views/Secured/corp/v241/en/flu_tg/flu_tg_transient_compressible.html

https://ansyshelp.ansys.com/Views/Secured/corp/v241/en/flu_tg/flu_tg_oneram6_wing.html

[N. M.]

Hello,

No, with "Hysteresis loop" I mean the variation in time of the cl of the rotating airfoil.