Geothermal Reservoir 2D heat flow modelling
 

Hi everyone i was wondering if i could get some advise with an issue i have.

I am trying to model a very basic geothermal reservoir simply as a 2D rectangle (x-y) plane in apdl i use the middle node at each end as the inlet and outlet boundary conditions and use the mass transport function in plane 55.

The issue i have (doing a transient thermal analysis) suddenly started encountering which i had no before for some reason is trying to apply the Temperature constraint to the inlet (20 deg) and the Heat flow(negative) to the outlet to simulate the heat being lost as water is pumped out.

Both the inlet and outlet are opposite each other and as soon as i enter a negative heat flow i eaither lose the effect of the temperatre constraint on the other node or the heat flow just does not apply.

Looking at an animation or at the nodal solution will only show one sides thermal effects while the other stays at the constant initial temp condition. I am unsure what is happening.

Sometimes when i try to input the negative heat flow at the outlet it will say "specified forces from the previous F command were applied only to the selected nodal load set"