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-   -   Visualize overset mesh movement (https://www.cfd-online.com/Forums/star-ccm/159996-visualize-overset-mesh-movement.html)

Alberto Damas September 29, 2015 06:48

Visualize overset mesh movement
 
Hello, I am trying to simulate a wind turbine using overset mesh and DFBI mode. I want to visualize and record the movement of the turbine during the simulation. ¿How can I do that?

me3840 October 5, 2015 20:26

Create a scene of the thing you would like to see. In the scene properties go to attributes>update and check the save to file option. Configure there how often you would like it to save, and run the simulation.

me3840 October 5, 2015 20:30

Also, if this is a wind turbine, why do you need overset for that? You can just use RBM.

Alberto Damas October 6, 2015 03:14

Because I want the wind velocity as an input.

Is there any way to calculate the inertia values for DFBI?

Thx.

me3840 October 6, 2015 19:22

Quote:

Originally Posted by Alberto Damas (Post 566706)
Because I want the wind velocity as an input.

Using the freestream velocity as an input and the turbine speed as an output does not require the use of an overset mesh. You can use RBM. RBM will be faster and produce less error than overset. You only need overset for large displacements with complex interactions. A wind turbine just rotates, it's simple.

To find the moment of inertia you need to know the mass distribution of the object, I don't think STAR-CCM+ can calculate it.

Alberto Damas October 8, 2015 04:55

You are right, I thought RBM had the rpm as an input. Thx a lot.

I have simulated the same geometry changing some parameters: wind velocity, inicial inertia values (I don't know what this means) and DFBI object mass. None of them change the rpm obtained. Do you know what I am doing wrong?

me3840 October 8, 2015 15:44

Make sure the region that rotates has its motion set to 'DFBI rotation and translation' and only enable rotating in 1 direction.

If you don't know what the inertia values are, you need to take a step back and read about some basic rotational kinematics, you shouldn't be doing this problem yet.
https://en.wikipedia.org/wiki/Moment_of_inertia

Nabuchadresar March 19, 2016 13:20

Quote:

Originally Posted by Alberto Damas (Post 567097)
You are right, I thought RBM had the rpm as an input. Thx a lot.

I have simulated the same geometry changing some parameters: wind velocity, inicial inertia values (I don't know what this means) and DFBI object mass. None of them change the rpm obtained. Do you know what I am doing wrong?

You found the problem?

Alberto Damas March 21, 2016 07:31

Yes, I don't remember what I did wrong but it works now.


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