[mva]

Hi

I am trying to model cell diffusion in a cube 1x1. I have defined concentration as additional variable and solve it as diffusion transport equation. However I want to solve a non-linear diffusion equation which has a form as shown in the attached file.
I have defined the whole cube as a subdomain apart from the upper surface in which I have assigned inlet boundary condition as (concentration) c=1. The other surfaces of the domain are set as walls with zero flux.
In the subdomain I have defined as source to be concentration^2. Since the diffusion-transport equation also includes density I have set the domain to be consisted of a material with density =1. However for an internal point far from the boundary I take even for t=0, cell concentrations only higher than 1 which is not reasonable.
I have no experience in working with ANSYS so could you please help me.

Thank you in advance.