Are Pyramid elements good for CFX solver
 

Hello friends,

Can anyone explain me in the following doubt

Case:

I am having a volume mesh on a geometry like a waterjacker for SI engine. I plan to create a hybrid mesh ( tet+ prism layers) In some places of my mesh ,I get pyramids . So my question is are pyramids here are an unwanted elements or I should still go ahead with such mesh or sit n redo the mesh till I get rid of pyramids

Thanks for your inputs

Re: Are Pyramid elements good for CFX solver
 

Hi,

CFX works with pyramid shaped elements. This is discussed in the documentation.

Glenn Horrocks

Re: Are Pyramid elements good for CFX solver
 

What documentation are your refering sir. Kindly give me reference number of the same.

thanks

Best Regards

Re: Are Pyramid elements good for CFX solver
 

Also I would like to know, that when you have hybrid mesh like tet with prism layers ,then pyramids are unwanted element as we dont actually specify for such element anywhere . Specially when I get pyramids in the area of interest.

Keeping pyrmaids is good for CFD reesults in general or not.Kindly clearify the above

Thank you Sir for your feedback

Best Regards

Re: Are Pyramid elements good for CFX solver
 

Hi,

Element shapes is discussed in the CFX documentation which by default is included with a CFX installation.

ICEM/CAD2MESH occasionally generates pyramid elements in heavily distorted regions of the mesh at the tet/prism boundary. While good quality pyramids are fine for the solver often the pyramids generated this way are of very bad quality and should be minimised.

Glenn Horrocks

Re: Are Pyramid elements good for CFX solver
 

Pyramids are necessary if the number of adjacent inflation layers changes, exposing a quad face at the side of a prism. The pyramid element connects the quad face to adjacent tetrahedral elements. You can reduce the number of pyramid elements by refining the surface mesh in the region where they are created and/or modifying your inflation settings. That said, CFX has no issues with pyramids, so it isn't necessarily worth the extra effort or additional mesh, unless you have other mesh quality issues in this region.

-CycLone

Re: Are Pyramid elements good for CFX solver
 

Thanks a lot people to have really cleared my doubts on pyramids elements.

Best Regards

Pratik Mehta