Use SOLIDWORKS Flow to analyze what the heatflux is to your fluid. If you know how much heat is coming in, you also need how much heat to take out (cool).
You can define a insulated container by selecting 'adiabatic wall'. And the ambient temperature (and pressure) at the openings can be defined with a 'boundary condition'.
That would work in an instantaneous way only since heat transfer is temperature dependant.
Assuming you fluid is a liquid in an insulated open container the only fluid your study should be concerned with is the air.
Model the fluid as a solid and set the tempature of the wall to your target temperature. Once the study reaches equilibrium (steady state) you should be able to get the power required to keep that surface at that temperature. This is the heat moving requirement of your cooling device