Artifacts in temperature profile across interfaces
Posted 10/06/2020, 18:57 GMT-4 Heat Transfer & Phase Change Version 5.5 2 Replies
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I am a relatively new COMSOL user, and I am having trouble with the Heat Transfer module (Multiphysics 5.5) where there are artifacts in the temperature profile of a system with interfaces or boundaries when solving the time dependent solution.
To illustrate the problem, I made a simple mock file (attached) that has a 2D geometry of alternating metal and water square domains (picture attached), where the initial temperature of the water is 300 K and the metal has a linear Gaussian profile of elevated temperatures spanning multiple domains. At early times (0-0.1 ns, picture attached) there are temperature spikes at the interface, and at some time points (0.01 ns, picture attached) the temperature profile within some domains is somehow inverted from expected, and at later times the whole temperature profile is inverted from expected with lower temperature in the center than the edges (10 ns, picture attached). In this case I established an interface conductance that is relatively high (faster than the timescale of the simulation), but the problem persists. I've also seen similar problems even with a slab of say metal with a 2D Gaussian temp profile, including ripples and spikes in the temperature profile.
I would greatly appreciate input on how to remedy such unphysical artifacts!