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-   -   Torque of Savonius turbine is not convergent (http://www.cfd-online.com/Forums/fluent/106660-torque-savonius-turbine-not-convergent.html)

fsifsi September 4, 2012 21:16

Torque of Savonius turbine is not convergent
 
2 Attachment(s)
Dear all,
I used Fluent 13 to simulate the Savonius turbine with obstacles was placed front of it as attached picture. k-w sst turbulence model and the second order discretisation were selected. However, I could not get convergence with time for Torque of turbine (Cm) while Cm is well convergent with time for the case of without obstacles.
Could you give me some advice, please.
Thanks.

husker September 5, 2012 03:04

Hi,

Flow is unsteady, so Cm is supposed to be unsteady. You have to consider other scalars to judge convergence. Then you will have an idea about how Cm oscillates.

Regards,

fsifsi September 6, 2012 00:29

Thanks,
Yes, the flow is unsteady so Cm should be oscillated, however, it should be repeated over one cycle or periodic of time.

Andrea1984 December 6, 2012 07:22

Hi fsifsi,

can I ask you how do you evaluate the turbine torque? Do you use the Cm value or the Momentum obtained from Result Reports?

Thanks,

Andrea

fsifsi June 23, 2013 20:52

I used Cm value

Far June 24, 2013 08:50

Lower the time step. how did you calculate the time step?


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