hi, i have made a model of a submarine, and i want to calculate the resistance. I can not mesh the model, this model is made up of arounf 100 surfaces. Please help in this regard. when everi mesh it, it gives warnings, and mesh is not generated, sometimes it gives a fatal error, and says it can't continue.

Hi,

What are you using to mesh it? I can tell you now that DesignModeller and CFX-Mesh will have a hard time on this type of geometry, but ICEM should work just fine.

Glenn

Yep,

ICEM will work well for a sub geometry. I've recently created a mesh around a sub and it didn't take too long either. Hexa or Tetra seem to work equaly well.

Regards James

Creating mesh with high quality is one of the most important things to get correct results from your simulation. However, if you ask the question to another ICEM user like that, nobody couldn't tell you exactly. If it is possible that show the geometry of yours, could you show me the geometry? I could help you.

A simple body of revolution submarine type geometry, with a O-Grid mesh will allow a reasonably high quality mesh to be produced using Hexa. Obviously a more complex shape will require a bit more skill!

Regards

James

i am using , cfx5.6, for meshing. Mesh param> Angular resolution, Mesh control>surface>Values>Angular resolution infalted boundary>2D region

Hi Salman,

The only way you are going to model this geometry with CFX-Build (I assume you have CFX-Build as you are using CFX5.6) is by using merged surfaces.

Alternately you could upgrade to the current version of the software and try ICEM. This type of geometry is easy to mesh in ICEM.

Regards, Glenn

Thanks for ur advice... i am really greatful. i'll install ICEM, and try it. Do u know about hyper Mesh? i have the software.... but i hav'nt used it.. some people say its a very powerfull software.

if you can just guide me, about the boundary conditions, in PRE. Basically i want to calculate the resistance of a submarine, and i am confused which, model i should use in pre ? and weather i use transient , or steady state ? further more if i use a specific fluid model, what would be the details, for that? like if i use SST or K-Epsilon then , what would be the values, for further sub, conditions like, Kappa value, k, Epsilon, and so on .... furthermore, my subarine is 86 m long, and my domain is 250 m long..... what should be the total time , and timestep?