[IRP]

Dear all
I am dealing with a problem in Star-CCM+, about the impact of droplet on a surface in which I have to insert a phase source as a filed function for considering the wetting condition of wall boundary.
Actually, I am going to provide phase source as a filed function in which whenever the surface becomes wet, permanently it stays wet.

I find a way in chapter 9 of a book
• An introduction to computational fluid dynamic: the finite volume method
H. K. Versteeg & W. Malalasekera
Which relates to the implementation of boundary condition.

At the beginning of this chapter, it gives the idea:
if we want to fix the flux of a variable at a cell face, can be done by introducing two overwhelmingly large source terms in the relevant discretised equation. For example, to set the variable Q at node P to a value Qfix the following source term modification is used in its discretised equation:
Sp = -10^30 and Su = 10^30 * Qfix
With these sources added to the discretised equation, we have:
(ap + 10^30) Qp = Sum (anb*Qnb) + 10^30 * Qfix

The actual magnitude of the number 10^30 is arbitrary as long as it is very large compared with all the coefficients in the original discretized equation. Thus, if ap and anb are all negligible the discretized equation effectively states that
Qp = Q fix
Which fixes the value of Q at P.

I would be appreciated if anyone could help me to that what kind of filed function would be suitable in this condition (star- CCM+).

Thank you very much in advance.
Iman