Defining non-constant Neumann Boundary Conditon

I am a little unsure if I am using the correct syntax for defining my non-constant neumann boundary condition for a time-dependent PDE.

specifyCoefficients(model,'Face',2,'m',0,'d',1,'c',Da,'a',0,'f',0);
specifyCoefficients(model,'Face',3,'m',0,'d',1,'c',Dg,'a',0,'f',0);

applyBoundaryCondition(model,'neumann','Edge',8,'q',0,'g',@gcoeff2);

function f = gcoeff2(~,state)
rhog = 1250;
rhoa = 1.150;
Da = 2.82*10^-4;
f = (Da.*rhoa./rhog).*(state.ux+state.uy);
end

Esentially I have two areas occupied by different substances, which share a common edge, Edge 8. I want to apply the equal flux boundary condition at edge 8 such that

Is the code for my function correct? Is it necessary for me to add in locations even though the gradient is defined by "state.ux" and "state.uy"? Also, since it is a time dependent PDE do I need to multiply everything by state.time?

Answer 1

[Ravi Kumar]

You do not need to model the interface BC explicitly. This condition should be automatically satisfied in the solution.

Regards,

Ravi