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-   -   wind turbine simulation, Ansys Post results question (http://www.cfd-online.com/Forums/cfx/79527-wind-turbine-simulation-ansys-post-results-question.html)

Laions August 26, 2010 05:32

wind turbine simulation, Ansys Post results question
 
Hi,

I've simulated 1/3 of a wind turbine (just one blade). I can not get the correct result...I belive the boundary conditions are OK as well as the convergence (residual set to 1e-5). The mesh is not fine enough but that's not the problem as it is fine on the blade.
When I use the calculator to extract the torque from the y axis (axis of rotation of my wind turbine) I've just got around 2000 Nm :confused:when the torque expected will be around 55000 Nm (it's the NORDTANK 500-41)...any advice will be much appreciated.

Cheers

ghorrocks August 26, 2010 06:38

Have you checked the basics?
http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F

stumpy August 26, 2010 16:05

I assume you have a rotating domain, and haven't just assigned a wall velocity on the boundary condition instead?

Laions August 26, 2010 19:36

Thanks ghorrocks for your suggestion, I've already checked the basics though.

Thank you stumpy, I do have a rotating domain for the turbine interfacing as a frozen rotor with the big domain. I'm quite sure that the boundary conditions are not the problem. That is why I'm a bit desperate...I even thought that maybe the direction of the torque is not in the axis of rotation but that does not make sense.

Thanks to both for replying.

paulo August 27, 2010 15:46

Hi,

Have you made a mesh convergence study of your problem. This can change the result a lot.

Best Regards,

Paulo Rocha

Laions August 28, 2010 03:15

Thanks Paulo, I haven't made a convergence study, I thought that if the mesh was fine enough around the turbine's blade was sufficient. Besides, I can not play much more with the mesh as it has reached 2.5milion of elements (with both domains) and my computer is limited, but IŽll follow your advise and try it, thanks again.

Best wishes

ghorrocks August 28, 2010 06:36

A mesh refinement study is a very basic check which should always be done in CFD. Clearly you did not even read the link I previously posted.

You can do mesh refinement studies which only coarsen the mesh. This will tell you whether the simulation you plan is possible with the computers you have available.

harjeetmaan September 20, 2011 05:13

Modeling Of wind turbine.
 
I am working on the simulation and modeling of wind turbines. Is anybody can help me to find out the quantity of backflow in the wind turbine and how to model the same using FLUENT.

Harjeet


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