# Points with very low heat flow

Hi there!

I am studying the heat flow on a geophysical project. I have a slab of ice with a thin layer of CO2 on top. The surface is quite flat but there is a gentle slope and small ups and downs due to the topography of the area. I know the temperatures at the surface and at the bottom of the model. I have run different simulations with different properties without problems but the heat flow at the surface is not as smooth as I expected. Solutions indicates that there are some points with very low heat flow at the surface of the model and I don’t know why. At the beginning I thought that these points could be due to the topography, but the differences in altitude are very very small. I have checked the geometry and it seems fine. Could I have a problem with the mesh? Any suggestions will be welcome.

https://www.simscale.com/workbench/?pid=5253760756425340809&rru=bd9f2f0d-695a-4edf-b55a-9cf8eeb00aea&ci=1239486d-b4c0-4589-b330-c961c6594906&ct=SOLUTION_FIELD&mt=SIMULATION_RESULT

Thank you very much!

Isa

Hi Isa, thank you for using the forum! Can you also provide a few screenshots, to indicate the issue? For example, the temperature distribution that you find unrealistic, etc.

Best regards,
Fillia

Hi Fillia,

Thank you very much for your help. This is a screenshot of the solution. The heat flow is similar in the whole area (as I expected), but there are some points in blue with anomalous low values.

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The issue here seems to be the mesh quality (your current model only has 40 k cells). Try to increase the fineness of the mesh, this should work better

Best regards,
Fillia

Hi Fillia,

Thank you very much for your help! I have increase the fineness of the mesh but the result is not improving. I have tried to solve the problem with a more simple geometry that consists in a cube with a thin layer on top. I have increased the fineness to 9 and I have also refined the top layer of the model, but results in heat flow are not constant in the surface. I think that the problem is the thin layer on the top of my model, and I guess I am not improving the mesh properly. Do you have any advice to improve the mesh efficiently?

Isa