Hi there,
I am modelling a heat flow within a tank, and I experience a huge difference in how fast my tank gets warm in relation to whether I implement some insulation or not.
Therefore I suspect, that FEniCS lets the heat within the domain diffuse out to some imaginary surroundings? Is it possible initialise the surrounding imaginary area to e.g. 20 degrees?
Thanks.
This all depends on your boundary conditions. There are three classes of linear boundary conditions, see: https://fenicsproject.org/pub/tutorial/html/._ftut1014.html
You need to enforce these through your variational formulation
For the temperature I only have a Dirichlet condition on the inlet to my tank where high temperature is let into the tank. What happens when I do not have other boundary conditions for the temperature?
You need to have boundary conditions for your PDE to be well posed. You should think about the physical interpretation of temperature over this boundary. See the previous link I posted + https://en.wikipedia.org/wiki/Robin_boundary_condition and https://tutorial.math.lamar.edu/classes/de/theheatequation.aspx