CFD Online Discussion Forums - how to implement Cmu changing with mesh coordinates

I need to make the constant Cmu in kEpsilon turbulence model in OpenFOAM-2.2.1 to change with height like this :

Cmu=pow(uStar,4)/(D1*ln(z+z0)+D2)

in which uStar D1 D2 z0 are predefined constants,and z is the z-coordinate of the mesh. I have tried it like this in the *.C file of myKEpsilon model:

Code:

Cmu_

  (

           IOobject

           (

                     "Cmu",

                     runTime_timeName(),

                     mesh_,

                     IOobject::MUST_READ,

                     IOobject::AUTO_WRITHE

           ),

           mesh_

  )

and in the *.H file i declared Cmu_ as the volScalarField.

My problem are :

1) From certain reference paper, the ignoring of the BC typeName in the parameters list of IOobject means the Boundary condition of the defined geometricField will be then calculated, so am I ritht to define the Cmu field like this or there is a better solution or even the Cmu could not defined as volScalarField at all?

2) If the above definition for Cmu field is appropriate, then how can i initialize the Cmu nonuniformly in the 0/Cmu file, as it's associated with the mesh coordinates, and for what the boundary conditions should applied , the Dirichlet BC ?

Thanks for your reply , and the attached file is the source and head files of myKEpsilon.

best regards .

Dong