I am modeling the temperature of the groundwater using heat equation. I have Dirichlet BC at the top but at the bottom I have constant temperature equal 12 degrees C (see attached pic). It is look like at the bottom we have zero flux. When I specify the Dirichlet BC I have a "knee" right before "neutral zone" which is not the case. So far I have 2 ideas how to implement it:
- I was thinking maybe the Robyn BC will help here?
- Maybe I need to implement somehow the [-hh * (T - T_inf)/k] as gradient there. When we have not 12C we will have the flux and when we have 12 then we will have 0 gradient.
what do you think? is it correct way of tackling this problem?