Problem with Grid convergence study

dialolema · June 12, 2010, 19:08

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 peaces of advice.

regards,

Dialo

ghorrocks · June 14, 2010, 18:33

This means you are not in the convergent section of the mesh sensitivity scale. You need a finer mesh again until the results start to be convergent.

June 12, 2010, 19:08	Problem with Grid convergence study	#1
dialolema New Member Join Date: Jun 2010 Posts: 3 Rep Power: 15	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 peaces of advice. regards, Dialo

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Grid size, convergence issues	franzdrs	Main CFD Forum	3	June 18, 2009 07:57
Continuity eq convergence problem	carno	FLUENT	4	February 8, 2008 04:04
Grid Independence problem for simple pipe geometry	chanchala	FLUENT	13	November 20, 2003 08:24
Combustion Convergence problems	Art Stretton	Phoenics	5	April 2, 2002 05:59
problem with grid dimension	nisheet goyal	Phoenics	1	June 18, 2001 09:28

June 14, 2010, 18:33		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,701 Rep Power: 143	This means you are not in the convergent section of the mesh sensitivity scale. You need a finer mesh again until the results start to be convergent.