Near wall treatment (k and epsilon)
 

Hi, I want to set dk/dn = 0 and depsilon/dn = 0 at the walls in Fluent where 'k' = turbulent kinetic energy and 'epsilon' is the rate of dissipation of turbulent kinetic energy. I wonder if it can be done !

Thanks
Sagnik

Yes. it can be done with the help of UDF

What are the default boundary conditions in Fluent for these variables at wall? And why you want to set these boundary conditions?

Hi cfd seeker, I understand there is a udf function called "DEFINE_WALL_FUNCTIONS". But that does not allow you to specify gradients of k and epsilon. Can you be a bit more specific about what UDF and whether you have seen anybody implementing it?

Hi far,

The default boundary conditions can be viewed at:

http://hpce.iitm.ac.in/website//Manu...ug/node510.htm


For the test case that we are designing we want to see whether it is important to model the wall properly to get the global flow features right ?

Thanks
Sagnik