[nandiganavishal]

Hello Foamers,

I am trying to solve a Laminar flow problem inside an axisymmetric cylindrical geometry with slip, where the slip length is specified by the user.

For this, I am trying to implement, the following boundary condition for velocity at the wall of a cylindrical geometry

dUz/dn = Uz/Ls

where Ls: Slip velocity
n = normal direction (radial direction in this case)
Uz = axial velocity

To implement this I was trying to write a FVPatch. Attached please find the codes for the above boundary condition.

The code compiled without any errors, but when running the solver, I received the following error.


gradientInternalCoeffs cannot be called for a genericFvPatchField (actual type USlip)
on patch nanopore_upperwall of field U in file "/home/cmn/Documents/RA_works/CNT_collab/case_2_2D_system/CNT_slip/rim_charges_only_no_reservoir/CNT_solve/0/U"
You are probably trying to solve for a field with a generic boundary condition.

From function genericFvPatchField<Type>::gradientInternalCoeffs( ) const
in file fields/fvPatchFields/basic/generic/genericFvPatchField.C at line 782.

FOAM exiting


Can you let me know what is the source for this error.

Thanks

Best

Vishal

U.txt

UslipFvPatchScalarField.C

UslipFvPatchScalarField.H

[wyldckat]

Greetings Vishal,

As far as I can understand, you already have gotten an answer for this on this post: http://www.cfd-online.com/Forums/ope...tml#post499941 - post #39 - in that it's best to derive or simply use the direction mixed BC.

Best regards,
Bruno