i have an electronic enclosure with a heat source, and a heat sink and fan. it seems like when i turn the mesh settings up, the heat cut plots show the same temperature, maybe a variance by 5°C. but the flow trajectories are a lot better, you can see their movement through the heat sink fins a lot better.
So I am wondering, if i just want to look at heat cut plots, will i gain any more accuracy using a higher mesh setting?
The heat flow is going to be much more sensitive to mesh size than temperature is, although both are affected. The reason is that the flow is related to the spatial derivative of the temperature. For somewhat complex resons, every derivative you take makes the solution conmverge more slowly.