[asal]

Hello all!

I want to calculate some a value in a UDF and I need to have "turbulence intensity". Is there anyone here know how can I return this value?
I mean a macro such as " C_U(c,t)" which return turbulence intensity.

moreover, is there any macro which return velocity magnitude? or the only way is to return components and then find the magnitude?

[`e`]

Fluent doesn't store turbulence intensity by default. However, you can calculate this value as turbulence intensity is defined as the ratio between the root-mean-square turbulent velocity fluctuations and the mean velocity.

The velocity fluctuations can be computed as a function of the kinetic energy (for example, k-e) or via the Reynolds stresses (RSM model). The mean velocity (not stored as a separate value by default) is the magnitude of the individual components.