Discussion Forum

Hello everyone,

I am new to COMSOL. For a personal project, I am trying to determine how (non-)effective it would be to cool down a case with electronics, by natural convection in a closed box filled with water. The electronics within the case dissipate 100W as heat, and the case is cooled down by natural convection (the whole system starts at 20°C).

The geometry and materials are very basic: the electronics are represented by a block of aluminium in a 3L volume of water. Then only 1/4 of the geometry is kept, to take advantage of the 2-plane symmetry. For physics, I am using Heat Transfer in Solids and Fluids (not sure if it is the most appropriate here?). I left most of the standard parameters as they were, then I added symmetry on the 4 relevant faces. All walls are considered as insulated.

Here comes my question: even though the case of electronics generates 100W, all this heat is not directly transferred to the water but rather transferred indirectly via a convective interaction, so the "heat source" function does not seem the most appropriate here. What do you think would be the best way to simulate my system?

I had a look at some tutorials online, but none of them gave me a satisfactory answer, so hopefully this post can help me and many others :)

Thank you for reading, and many thanks in advance for your help. The files should be attached to this post. Cheers, Sébastien