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muneer Ismael (muneer)
Member
Username: muneer

Post Number: 9
Registered: 12-2007
Posted on Saturday, July 04, 2009 - 02:59 am:   

My Dear Sir,
I am solving a bubble problem (spherical coerdinates), I am facing a problem in simulating a natural boundary condition an the origion, i.e. a point. Please, how can this be done?, many thanks
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Robert G. Nelson (rgnelson)
Moderator
Username: rgnelson

Post Number: 1274
Registered: 06-2003
Posted on Sunday, July 05, 2009 - 08:26 pm:   

If you are constructing a 1D model in spherical coordinates, then the default NATURAL()=0 is the only BC that makes physical sense at the origin, so you don't have to do anything.

You can, if you wish, use the POINT LOAD() or POINT NATURAL() boundary condition following any declared point on the domain. However, a non-zero POINT LOAD() will be treated as a source rate applied to the specified node, and will probably generate a singularity in the solution and dense regridding. You would probably do better with a small central bounding sphere with a specified flux.

If you are not constructing a 1D model, then the POINT LOAD() boundary condition is not advised.

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