How to define the turbulent k near the wall ?
hello everyone, :)
I wish to define the solution of the turbulent kinematic energy solution near the wall, in Fluent. My case is standard ke with standard wall function. From the ansys help we can see that the kequation is solved in the whole domain including near the wall, while the epsilon adjacent to the wall is calculated from the nearwall equ with is derived from the local equilibrium hypothesis. After the solution I found that the production of k (Gk) is zero everywhere on the wall, which is very different from the Gk equ based on the local equilibrium hypothesis. I wish to give a definition of the k in order to force the local equilibrium near the wall. Could anybody give some advice how i can do this? Many thanks!! :) 
There is no fluctuation on the wall ( the velocity is always zero) so that the turbulent kinetic energy k vanishes on the wall.

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I saw in many literatures they specified the value of k on the wall, which is, to give a Diriclet boundary for the equation. For example, some can specify the k as u*^2/sqrt(Cmu), which is, to force the local equilibrium on the wall. Or some can give a zero k on the wall. I checked the results of the Fluent on an external flow around a cylinder with ke and standard wall function. When I compared the computed k to the "u*^2/sqrt(Cmu)" , I saw in the wake region the computed value differed a lot. I wonder whether this would be a key point to cause the differences between my results and those in the literatures. So I wish to specify the k on the wall, in the Fluent, eg. though a UDF~~ Could anybody shed some light~~:) Attachment 21716 
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