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Zolet November 11, 2008 07:50

Hi everyone

I need to simulate the steady position of a amphibious vehicle in calm water (buoyancy), and the drag of the vehicle in calm water.

Im pretty sure Star-CCm+s 6DOF can do that.

The question is, Whats the level of difficulty to model a problem like that? I havent seen any tutorial to help me in the Star CCM+ 3.04 user guide…

Im concerned about how difficult is to model (setting the physics correctly), to mesh (how many grid cells?) and converge (is this difficult to converge? How long does it take to run one case???) a problem like that. Besides, what would be a good hardware configuration to run a case like that?

I know that the runtime depends of hardware and mesh refinement for example, but any estimative would be appreciate. I have two months (full time) to work on this.

Thank you in advance

MAB November 11, 2008 08:21

Re: 6DOF
I think you would need more than 2months. But it depends on your prevous experience. setting the physics and initial conditions very easy as long as you know these parameters already. meshing does require some experience. especially depending on your problem setup. Good Luck

ping November 13, 2008 04:40

Re: 6DOF
2 months full time is stacks of time from knowing nothing - STAR-CCM+ is very easy to learn and ideal for this case. Here is a link to a video tutorial on doing a ship in 6DOF. This shows everything other than the meshing for such cases:

(NB place the VOF Hydro. press. FF on the outlet!)

If you mesh carefully using a volume source on the water surface with aniso. cells you can have a model with about 300k auto trimmed hexas which will run in a few hours on a modern PC - STAR-CCM+ VOF solver is very efficient.

Chen November 18, 2008 22:36

Re: 6DOF
Dear Ping and dear ccm experts,

The memo media is very good material to learn the basic skill for the subject case. It wolud be much appreciated if you can send me the mesh file (ccm) or sim file to try this tutorial. (It is not included in the tutorial material of ccm 3.04.) If it is too big to send by Email, can you post in suit web space or ftp site?

Thanks in advance and best regards

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