I am considering adding Flow Simulation to our SW suite and was wondering how well it predicts natural convection. My application is primarily finned heatsinks in various orientations. How does Flow Simulation compare to IcePak? It seems that IcePak is the defacto standard to which all electronic CFD packages are compared to.
I can't vouch for finned heat sinks or IcePak in natural convection, but I did a project with a large choke (400kVA) and the measured temperatures were within 2F of the actual temperature (110F).
It might not be PCB grade results, but given the deviations between the choke model and the actual windings the choke manufacturer was shocked it was that accurate (they inquired about buying Flow but I believe they decided to just contract simulations on critical projects).