I am having an issue with flow simulation in regards to a time dependent thermal study. I am basically looking for the cooling time of a liquid in a sealed chamber. The fluid would begin at room temperature and I have a cold condition on the outside of the box walls. The simulation runs and I can see the temperature drop but when I go to "time dependent" in general settings the simulation temperature never drops (I need to be able to determine cooling time of liquid to -40 to estimate test down-time.) I have an outer wall condition on the aluminum box @-40C. I am assuming this is a simple sim to run and I must just be missing something very basic but I can't figure it out after hours of messing with settings etc. Can anyone point me in the right direction? Thanks in advance.
Tory
The automatic time step was extremely low, something on the order of 1e-5 seconds. I chose a manual time step (in the Calculation Control Options) of 1 second and got a reasonable progression (I didn't run until convergence, but I don't think there would be any issue.) This is what the goal plot looks like:
Looks to me like it will take a few hours at this rate to reach -40C.
One thing I noticed, you don't need to use a fluid subdomain here. Just set your working fluid as the default fluid.