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-   -   unable to float the boat!! (http://www.cfd-online.com/Forums/star-ccm/96000-unable-float-boat.html)

sanjay January 10, 2012 02:31

unable to float the boat!!
 
2 Attachment(s)
I am working on tunnel hull speed boat. The wave generated is making the body submerged even with less amplitude of wave. Please help me resolve the problem!!!!:(

ping January 10, 2012 04:30

ensure your boat flows in still water first in still water - weight could be incorrect.

sanjay January 10, 2012 05:24

1 Attachment(s)
it doesn't folat it appears submerged. Should I change the position of ship ? serious help required!!!

ping January 10, 2012 05:51

as I said you need to run with zero in/out flow the case for a few seconds (eg using a timestep of about 0.05s) and monitor vertical motion (sink). if there is no movement then the gravity forces are balanced by the bouyancy forces. if the hull is in a submerged condition after this run, then your hull mass is too high for this hull shape - simple hydrostatics. do the boat tutorial in the Help if this does not understood. ensure you have freed the required DOFs!

sanjay January 11, 2012 00:01

I found the solution myself. Actually its got nothing to do with buoyancy. Just go to VOF wave >> head wave >> adjust the point on water level, its simple as that;). Thanks for the sharing your opinion:). Some more questions to come:confused:

http://aerosapien.blogspot.com/

ping January 11, 2012 01:54

well if you had followed my instructions, the boat would rise to the surface of where your flat wave had been incorrectly set, so it is in fact about bouyancy!

sanjay January 11, 2012 23:54

I do agree about buoyancy. What u said is right.:)

regards
http://aerosapien.blogspot.com/


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