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-   -   Velocity of flow v time (https://www.cfd-online.com/Forums/fluent/106521-velocity-flow-v-time.html)

 MitsubishiEvo6 August 30, 2012 23:51

Velocity of flow v time

Hi,
I'm hoping you can help me out here. It'll probably turn out to be quite a simple thing to do, but I can't fathom out how to do it.

I have a modelled and meshed a flow meter that features vortex shedding using Ansys Workbench 12.1 or 14, depending which computer I use. It's in 2D and I'm using the k-epsilon model.

Firstly, as the flow is constantly switching from side to side of the bluff body in the middle of the flow meter, as it should, I assume that it is unlikely to converge or take a long time to converge unless I change the convergence criteria from the defaults (I've run simulations with a modest mesh for hours without convergence). Is this correct/likely?

Secondly, to determine the flow rate through the meter, I wish to determine the frequency of the flow as it switches from side to side of the bluff body as this is proportional to the flow rate. I've set a surface monitor close to the bluff body to measure the velocity of the flow and when the simulation is run a plot shows the velocity to increase and decrease. However, this is velocity v iteration. I'd like velocity v time. How can I do this?

Finally, I'd like to create a set of contour plots at set intervals of time to show a complete cycle of the oscillation of the flow either side of the bluff body. This is related to the second point in that I am not aware of how to determine time as opposed to iteration. Is there a tool or way of doing this?

Any help on any of these points is greatly appreciated.

Thanks,
Ant