Problem with Grid convergence study

dialolema · June 12, 2010, 20:11

I am simulating 5 degree slice of a cylinderical reactor having two inlets at the top face of the slice, one for solid fuel & one for oxygen inlet, and an outlet at the bottom face of the slice. This model has two symmetry face and the rest are walls.

I have created three meshes using CFX-mesh for my grid convergence study. I have used global mesh scaling factor, point control and infilation to generate three meshes for my study. However, the solutions from the three meshes are not consistent meaning, the solutions are not in increasing or decreasing order. I have tried quite a lot of time and problem persist. Is there any one who colud give me a peaces of advice.

regards,

Dialo

Max Efficiency · June 14, 2010, 08:12

The slice of 5 degree could be too small. Increase this value and simulate 15 degree or even more of the reactor. Maybe you need a slice of up to 45 degree. Even if a process has a symmetry you cannot make the slice infinite small. The necessary sice of the slice differs from case to case.

June 12, 2010, 20:11	Problem with Grid convergence study	#1
dialolema New Member Join Date: Jun 2010 Posts: 3 Rep Power: 16	I am simulating 5 degree slice of a cylinderical reactor having two inlets at the top face of the slice, one for solid fuel & one for oxygen inlet, and an outlet at the bottom face of the slice. This model has two symmetry face and the rest are walls. I have created three meshes using CFX-mesh for my grid convergence study. I have used global mesh scaling factor, point control and infilation to generate three meshes for my study. However, the solutions from the three meshes are not consistent meaning, the solutions are not in increasing or decreasing order. I have tried quite a lot of time and problem persist. Is there any one who colud give me a peaces of advice. regards, Dialo

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June 14, 2010, 08:12		#2
Max Efficiency New Member Join Date: May 2010 Posts: 24 Rep Power: 16	The slice of 5 degree could be too small. Increase this value and simulate 15 degree or even more of the reactor. Maybe you need a slice of up to 45 degree. Even if a process has a symmetry you cannot make the slice infinite small. The necessary sice of the slice differs from case to case.