I am having a bit of a problem with defining a boundary variable that has a counterpart defined on the model domain but with a different value.
For a simple spherical particle, I am modeling the classical diffusion equation dc/dt + div(J) = 0 Where J is the flux defined as J = -D*grad(c) using a general form PDE. For the domain I am defining a domain variable D as a function of concentration c (i.e. D(Domain) = f(c)) and for the boundary that completely encloses the domain I define a boundary variable D as a constant value.
For additional information, I define a boundary flux "Jo" on the boundary as well.
When I solve this problem and plot intermediate "D" values, I find that D changes on the boundary which I did not expect to happen.
Can someone please give me some insight on what might be going on or what I am possibly doing wrong?
For a simple spherical particle, I am modeling the classical diffusion equation dc/dt + div(J) = 0 Where J is the flux defined as J = -D*grad(c) using a general form PDE. For the domain I am defining a domain variable D as a function of concentration c (i.e. D(Domain) = f(c)) and for the boundary that completely encloses the domain I define a boundary variable D as a constant value.
For additional information, I define a boundary flux "Jo" on the boundary as well.
When I solve this problem and plot intermediate "D" values, I find that D changes on the boundary which I did not expect to happen.
Can someone please give me some insight on what might be going on or what I am possibly doing wrong?