Error 1000: NaN detected in Residual:Pressure correction equation, phase (0)

[samah1995]

Hello,

I am trying to solve a case of nanofluid inside an enclosure using a two-phase model, where the upper and lower surfaces are adiabatic, the left wall is heated, and the temperature of the right wall is less than the left wall.

I am getting this error " Error 1000: NaN detected in Residual:Pressure correction equation, phase (0)"

Can you help me how to solve it?

new_2022-03-06T215829.412561.zip (68.2 KB)

[cgw]

Hi Samah. Sorry, I do not have a quick answer to this question, but when a singular matrix is detected, it’s a sign that something has gone wrong in the simulation. Searching the forum for ‘singular’ comes up with a few threads on this topic:

A code error when i run a case with tfm

Somehow, there is a singularity when the bed packs. I was able to run to completion by turning off the preconditionner and setting norm_s = 1 or by turning off the preconditionner and leaving norm_s undefined.

Singular matrix detected

Thank you for your patience. I don’t have a solution yet, but this is probably due to a bad mesh. Others may provide additional guidance. A few points: The STL file looks better, but look at the output: STL file(s) successfully read. Total number of facets read =134588 Number of valid facets =104889 Number of ignored facets = 29699 This is an indication small triangles are still present. You may get better results by reducing the facet angle tolerance and decreasing the intersec…

Please let us know if this answers the question.

– Charles