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Old   September 2, 2009, 03:12
Default transient simulation
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Yi-Lang Chen
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Dear experts:

I simulated free surface in transient model. It have to use mesh

adaption to solve free surface in steady model. Now, I have to simulate

free surface in transient model. But it can't use mesh adaption in

transient model. If it can't use mesh adaption taht causes the free

surface to be very rough. Does it have another solution method?

I have tried to let grid much finer. But it couldn't solve.
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Old   September 2, 2009, 05:49
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Glenn Horrocks
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CFX does not support mesh adaption suitable for transient free surface work. The dynamic mesh adaption in Fluent does not work very well either but it is much better. I have had to develop my own free surface dynamic meshing in Fluent to get it to work properly.
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Old   September 2, 2009, 23:16
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Dear Ghorrocks:

So....you mean if I want to use mesh adaption for trasient model. I have had to

develop free surface dynamic meshing. Do you have any relate to free surface

dynamic meshing reference that could let me study.

And I have anothor question. Before I use flow-3d package that can solve free

surface problem very well for trasient model. Morever flow-3d doesn't need to carry

any hypothesis for mesh adaption function. Do you know how did flow-3d solve free

surface problem for trasient model. Thanks!!
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Old   September 2, 2009, 23:56
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My work on dynamic meshing for free surface modelling is proprietry so I can't share it - sorry. It is on Fluent anyway so it is probably not too useful for you.

All of these softwares can do free surface modelling. Your question was about dynamic mesh adaptation in free surface modelling - None of these softwares (CFX, Fluent or Flow3D) have a dynamic mesh capability for free surface modelling which works well. Flow3D has a different approach to VOF than CFX or Fluent in that it can model with a single fluid approach. While this makes it easier to model many free surface simulations it does have some inherent assumptions that the lighter phase does not affect the heavier phase.
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Old   September 3, 2009, 01:44
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Dear Ghorrocks:
Very thanks your precious responce. ^_^
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Old   September 3, 2009, 03:55
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Dear Ghorrocks:

How much did you spend time to write your dynamic mesh program? Is it program

difficult? Because my case is 3-D problem Whether the program was more difficulty.
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Old   September 3, 2009, 06:10
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Many weeks of work. It is not easy.
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