Learning Forum

[mahereid97]

Hello
I am trying to get the Moment coefficient of a wind turbine and match it to experimental data.

I am using the LES dynamic Smagorinsky Model.

I am not sure what discritization schemes are the most accurate, and wether I should be using Simple/c or Coupled. I tried a lot of configuration but none of them are close enough. I refined the mesh and got the same Cm values. Time step is equivaent to 0.1 degrees of turbine rotation.

If you have any suggestion please let me know
Thanks

[Kalyan Goparaju]

Hello, 

Please start with the default settings, which are quite robust, and only change if you they don't work.

More importantly, did you make sure that the reference values are correct? 

Thank you, 

Kalyan

[mahereid97]

Hello I tried the default settings but I did not get close agreement with the experimental data.
And the reference values are all set correctly.

[Kalyan Goparaju]

Do you have sufficient mesh resolution and small enough time step to capture all the appropriate scales? Have you tried performing a steady state simulation to see if you can get a reasonable value?

[mahereid97]

I have a very clustered mesh around the blades (120 layers of inflation starting from y+ ~ 0.2) and growth rate is around 1.04
Time step is in order of 10^-5 equivalent to 0.1 degree of rotation so I am not sure if it is enough.
Steady state does not really work for me because the turbine is in the turbulent wake of another body.

Is there a way to check the turbulence scales so that I can fix the time step?

Thanks