Solution dependent material coefficient? How to use specifyCoefficients in pdetool (for a time dependnet PDE solution)

Hi, I have set up a time-dependnet PDE (Fick's law of difusion) in pdetool (v2017) which appears to give me expected results.

Now, I want to make a material property (diffusion ceoffincent) solution dependent (concentration).

I scanned through the documentation and but I am finding it difficult to understand.

How do I use specifyCoefficients

(e.g. specifyCoefficientsspecifyCoefficients(model,'m',0,'d',1,'c',2.3e-3,'a',0,'f',0,'Face',1) is currently set, where 2.3e-3 is the concentration independent diffusion coeff)

when material parameter (in my case the diffusion coefficent) solution dependent

(i.e 2.3e-3 is now 2.3e-3*u*u, where u(x,y) is the solutiion)?

Answer 1

[Ravi Kumar]

Define a function or a anonymous function handle as per the prescribed format. For example you can define:

cFcn = @(region,state) 2.3E-3*state.u.* state.u;

Then use it in specifyCoefficients as:

specifyCoefficients(model,'m',0,'d',1,'c',cFcn,'a',0,'f',0,'Face',1)

Regards,

Ravi

[JM]

thanks. pdetool used to be intuitive and userfriendly. No longer.....