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Akceptor June 12, 2010 01:23

Strouhal number in FloWorks
How can I determine Shrouhal number in COSMOS Floworks. For example for classic sample "flow around circular cylinder"?
How can i meadure vortex frequency?

Boris_M September 1, 2010 03:43

Hi Akceptor,

the Strouhal number as you know consists of the reference time, flow velocity and reference length to calculate. This is not possible as a visualization if you wanted that but there is a "Calculator" inside FloEFD and it should be also in FloWorks but don't know for sure.
In that calculator you do a right click on a row and select "new formula" and then you find the Strouhal number under "Dimensionless Parameters".
Now you just have to enter these three values and it will calculate it for you. It's a little Excel style.

You may now say the Strouhal number is depending on the frequency but we know the frequency is just the peridodic repeating of a event such as a maximum value or a vortex so you would only need the time between the two vortices, or the time for one vortex to reach a marked position of a previouse vortex. Therfore you'll probably have to run a transient analysis. If you need it just roughly you probably can also estimate the time by the distance between the two vortices and the velocity they are moving.

This should also clarify your second question.

I hope this helps,

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