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MAB August 8, 2008 07:04

Transient Case
 
I am getting around 6 million cells and it is a transient case. How long you think CFX will take to complete this simulation. the smallest cell is about 0.005m . any advice about time step. (coz it is crashing on first loop naming it a Fatal Over Flow). any advice please? thanks

Rogerio Fernandes Brito August 8, 2008 07:50

Re: Transient Case
 
Did you create any own material? (donīt forget the input the Cp, ro (density), and K).

You might have at least 8 GB of RAM!

Change the turbulence model (and the same for the scheme of convection)

Decrease the time step. (use 0.1 s)


Glenn Horrocks August 11, 2008 01:17

Re: Transient Case
 
Hi,

6M cells in a low Re simulation - easy, quick, but need a bit of memory. 6M cells in a multiphase, transonic, reacting flow with mesh motion - you will need a supercomputer.

Without more detail we cannot help.

Glenn Horrocks

MAB August 11, 2008 06:02

Re: Transient Case
 
Hi thanks I think it is low Re , multiphase flow( water waves) ...what do you think about it. do i still need a supercomputer???

Glenn Horrocks August 11, 2008 18:39

Re: Transient Case
 
Hi,

Modelling water waves is tricky and slow on CFX. Again it still depends on many things but you should be able to run on a machine with a good deal of RAM (or better still a cluster). If you are just modelling water waves you will probably find better software which will run much faster.

Glenn Horrocks

MAB August 12, 2008 04:56

Re: Transient Case
 
Thanks Glenn, Could you please suggest me anyother sofware for this pupose of modellling water waves. thanks MAB

Glenn Horrocks August 12, 2008 22:33

Re: Transient Case
 
Hi,

We have fluent and CFX and fluent does it much better. There are also myriads of other software for coast and ship design which are worth looking into.

Glenn Horrocks

MAB August 13, 2008 07:52

Re: Transient Case
 
does fluent has moving mesh or cut cell capability???


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