Dear everyone,

I met one problem about the turbulent boundary conditions which are intensity and length scale from experiments. I found that in Fluent I could not use UDF to define boundary conditions of turbulent intensity and length scale. Only k and episilon can be defined as UDF in Fluent. I am wonderring if my finding is right or not. And I am wondering by which correct way I can transfer from intensity and length scale to K and epsilon. Did you consider this kind of problem before? I am very appreciated of your help if you can suggest me some good ideas. Thanks.

Zwdi

Hello Zwadi,

This is explained in detail in the FLUENT manual, section 6.2.2. There you have the equations that relates the turbulent kinetic energy and dissipation rate to intensity and length scale. Allthough you are correct regarding the fact that you cannot directly specify intesity and length scale in your udf. You have to calculate k and e from your intesity and length scale via the equations presented in 6.2.2.

/Mattias

hi mattias,

Thank you so much. I have more confidence on this points.

Best, zwdi