Implementation of Functional Boundary Condition using laplacianFoam.
 

I am solving Laplace equation which states that second derivative of potential (E) is zero. I am using LaplacianFoam as solver. My geometry is in 2-D.

At one patch I have to implement functional boundary condition which is

dE/dx = k* [exp ((E-Ec)/a)- exp ((E-Ea)/b) ]

where k,Ea,Ec,a and b are constant and I have to solve for E.

I am unable to implement the boundary condition. Can anyone help me with implementation.

Thanks in advance.