Dual domain versus 3D analysis

[MarkMcDonald6284]

Hi guys, I have a part model with a wall thickness of .10".  It defaults to dual domain during the part import.  The analysis shows 11,451psi injection pressure.  If I rerun the analysis using 3D I get 26,000psi.  The 26,000psi is closer to reality when we sample the mold.  I do not understand the difference.

Thanks for any wisdom that you can share.  Mark

[kristen.kilroy]

Hi @MarkMcDonald6284! 

Can you share a picture of your part? I am wondering if, even though it defaulted to DD during import, the reason for the lower pressure could be due to unmatched surface mesh.

Dual Domain is essentially surface mesh, and if the 'top' and 'bottom' mesh do not match throughout the part, an incorrect thickness can be measured by the solvers, resulting in incorrect results. Since the part defaulted to the DD analysis type, I would probably guess that it is a thin part with fairly simple geometry, which typically would be correct. 

• Autodesk Moldflow Insight Online Help: Mesh Match (Dual Domain) [although this is for Moldflow Insight, rather than Moldflow Adviser, the same concept of having to match the surface meshes applies]
• Autodesk Moldflow Insight Online Help: Dual Domain Mesh Match Diagnostic [again, this is pulled from Moldflow Insight's help, however same concepts apply for Adviser - note there are no mesh manipulation or diagnostic tools within Moldflow Adviser]

Another thought is - did you have the feed system modeled in both analyses? This can introduce additional pressures, that could also be why there is a significant difference. 

Hope this helps! 

[mtrujil1]

You need consider the Quality of mesh for DD (Aspect ratio >6, Precise Match, and lenght & qty of elements.

in my opinion and experience (correlation with real molds) 3D mesh results are more accurate. (near to the reality)

Regards