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Ansys Learning Forum › Forums › Discuss Simulation › Fluids › Calculation diverges when mesh is refined › Reply To: Calculation diverges when mesh is refined

February 1, 2024 at 10:30 am
Manish Patel
Subscriber

The pressure outlet is at the top. Those protruded rectangular fins are the heated walls. The side walls are adiabatic.  

As I said, the coarse mesh did work without error and got some results with visible boiling. Coarcer mesh also has jump in cell size and works good.

But, as soon as I replaced the mesh with finer one (2 times finer), the simulation diverges. 


The mesh chek for coarse gives following output in Fluent:

Minimum Orthogonal Quality =  1.00000e+00 cell 2886 on zone 23 (ID: 6469 on partition: 2) at location ( 5.21808e-03,  1.42462e-01)
Maximum Aspect Ratio =  5.03856e+00 cell 2924 on zone 23 (ID: 4861 on partition: 1) at location (-5.21808e-03,  1.44615e-01)

The mesh check for finer mesh gives the following output in Fluent:

Minimum Orthogonal Quality =  1.00000e+00 cell 3908 on zone 23 (ID: 23410 on partition: 2) at location ( 3.87500e-03,  1.49462e-01)

Maximum Aspect Ratio =  6.06954e+00 cell 4647 on zone 23 (ID: 19736 on partition: 4) at location (-1.05750e-02,  2.09605e-03)

The zoomed-out and zoomed-in snapshots of the coarse and fine meshes are attached here. 

Coarce:

Fine: