Special Type Boundary Condition

[udemirezen]

Hi,
Can we create a special type of boundary condition given below:
Dg(s(t,1)) ~ ks*(sa-s(t,1)),
Dg is the differentiation on r (spherical coordinates) Dg(f(t,r))/Dr.
If yes, could you show it?
Thank you

[shuheng-liu]

Hi @udemirezen , I'm not sure I understand the notation used here. Can you clarify a little bit more?

[udemirezen]

Hi @udemirezen , I'm not sure I understand the notation used here. Can you clarify a little bit more?

Sorry for unclear explanation. I mean:

these kind of boundary conditions. Here rl is lower value, ru is upper value rl =0 and ru=1 in this case.

[udemirezen]

Hi @udemirezen , I'm not sure I understand the notation used here. Can you clarify a little bit more?

Sorry for unclear explanation. I mean:

these kind of boundary conditions. Here rl is lower value, ru is upper value rl =0 and ru=1 in this case.

especially these Boundary conditions that i wanted to ask:

Is This type of BVC possible to implement?
Thank you

[shuheng-liu]

Hi, this looks like a Robin condition if I understand correctly. Currently, we don't have a stable implementation. However, I would recommend adding the boundary constraint to your loss function. You can override the additional_loss function of your solver. Check this documentation and this line of code for more. Note your new additional_loss(self, residual, funcs, coords) function must return a scalar (usually mean squared residual) that will be minimized.

Feel free to reach out if are not sure how to do that.