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Potential errors with Surface Maximum node

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I'm curious about how maximum value measurements are found in FEM, in particular: results using the Surface Maximum node. I know that issues of infinite stress can arise at corners in structural modeling and I wonder if I am experiencing something similar in a heat transfer model.

I am modeling a half channel of a heat exchanger. I have noticed something odd while performing a mesh sensitivity analysis. Sparing you all of the details, one of the measurements I am interested in is the maximum temperature on the channel wall. To find this I am using a Surface Maximum node. As I refine the mesh initially (from 10,000 elements to 20,000, to 30,000...) the max values and my other measurements do not change (<0.5% difference). If I continue to refine the mesh (60,000+ elements) the max temperature begins to rise and shows no signs of leveling off. All other measurements I'm taking remain the same as they did with a coarser mesh. I have found the same issue with maximum heat flux. Is this some type of numerical error, or artifact of FEM? Or is it actually physically meaningful?

Thank you for the help,
Bryan

0 Replies Last Post 11 sept. 2017, 18:50 UTC−4
COMSOL Moderator

Hello Bryan Burk

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