Learning Forum

[snr1]

How to calculate a swirl strength or swirl number in post process tool for swirling flows.

[Rob]

In Fluent I'd tend to use a custom field function, usually of axial & circumferential flow. Alternatively I may want to view angular velocity which tends to need a bit more maths. 

[snr1]

Okay sir, but how we can find from that?

[Rob]

Find what? Custom Field functions are under the "User Defined" tab. 

[snr1]

I am using the following definition to calculate the swirl number. How to calculate this expression in Fluent?

How to calculate the "r" In the numerator and "R" in the denominator in CFD post?

[Rob]

Assuming r and R are related to radius you need to know the swirl centreline and position you're interested in. This may well involve trigonometry and/or Pythagoras Theorum.

[snr1]

Thank you, sir, for your suggestion. But how one can calculate the above expression from the Fluent? If it is by custom field functions, then how we can define the above expression in the custom field functions?

[Rob]

That you need to work out yourself: we're not allowed to give specific engineering advice. Remember you can also then plot/report surface integrals/average etc on surfaces of the custom field function.