[raunakjung]

Hello everyone

I am trying to calculate integral length scale in Fluent for a fluidic oscillator. My objective is to carry out LES simulation.
I am using the expression :

integral length scale l0 = k^1.5 /e where k - turbulent kinetic energy and e is eddy dissipation.
During post processing maximum and minimum values of turbulent kinetic energy and eddy dissipation rate is given. Can these values used to determine integral length scale.

If not what is the process to determine integral length scale?

Thank You

[CeesH]

You can make a custom field fuction (under define) with the required equation. This will calculate the length scale in every grid cell. You can then plot it as a contour plot, export it, like you could do with any field. You can also define an equation in CFD post alternatively.

[raunakjung]

Originally Posted by CeesH

You can make a custom field fuction (under define) with the required equation. This will calculate the length scale in every grid cell. You can then plot it as a contour plot, export it, like you could do with any field. You can also define an equation in CFD post alternatively.

Thank You for your answer. I made a custom field function calculator to determine integral length scale. I have the maximum and minimum values. My goal is to carry out LES simulation. Which value should I use to determine the size of my grid for LES simulation. The maximum or minimum.

Thank YOU

[CeesH]

For LES, calculate the Kolmogorov scale, and try to locally refine your mesh to approx. 5-10x the Kolmgorov scale in the bulk. The finer, the more scales you resolve of course.