dynamicMesh case setup simpleton questions

tellico · January 16, 2014, 15:57

im trying to set up a dynamic mesh case for a ball free falling in a box. the geometry is simple but I'm confused as to how to specify the ball. is it a "cut out" of the box geometry, or simply internal "faces"?

if I understand correctly, the "pointMotionUx" files are were I would then specify the movement of the ball, but do I also need to specify the movement in the U file?

mturcios777 · January 16, 2014, 17:13

If the ball itself doesn't need to be simulated (e.g. no heat transfer in the ball), you can cut it out of the domain and set the generated boundary as a moving wall.

You will need to change the mesh topology throughout the simulation as the ball falls. Depending on how you mesh your domain you can either use layerAdditionRemoval with something like the movingConeTopoFvMesh, or use fvMotionSolver dynamic mesh and remesh the domain when the mesh quality deteriorates.

tellico · January 17, 2014, 12:41

Thanks for the tips. I got the simulation to run although I'm not sure where to account for the effect of gravity. Is there a tutorial that deals with free fall?

January 16, 2014, 15:57	dynamicMesh case setup simpleton questions	#1
tellico New Member Debb Join Date: Sep 2011 Location: Toronto, Canada Posts: 20 Rep Power: 14	im trying to set up a dynamic mesh case for a ball free falling in a box. the geometry is simple but I'm confused as to how to specify the ball. is it a "cut out" of the box geometry, or simply internal "faces"? if I understand correctly, the "pointMotionUx" files are were I would then specify the movement of the ball, but do I also need to specify the movement in the U file?

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January 16, 2014, 17:13		#2
mturcios777 Senior Member Marco A. Turcios Join Date: Mar 2009 Location: Vancouver, BC, Canada Posts: 740 Rep Power: 28	If the ball itself doesn't need to be simulated (e.g. no heat transfer in the ball), you can cut it out of the domain and set the generated boundary as a moving wall. You will need to change the mesh topology throughout the simulation as the ball falls. Depending on how you mesh your domain you can either use layerAdditionRemoval with something like the movingConeTopoFvMesh, or use fvMotionSolver dynamic mesh and remesh the domain when the mesh quality deteriorates.

January 17, 2014, 12:41		#3
tellico New Member Debb Join Date: Sep 2011 Location: Toronto, Canada Posts: 20 Rep Power: 14	Thanks for the tips. I got the simulation to run although I'm not sure where to account for the effect of gravity. Is there a tutorial that deals with free fall?