[cccxi]

In cfx pre-process, we find a option is mesh stiffness in domain setup.The mesh stiffness have three models: increase near small volume, increase near bounderies, and value.
I do not know the function of these thress mesh stiffness models. And I refer to the help document, find the mesh stiffness is about the mesh move.

When i choose the 'value' mesh stiffness model, and change it value, the computer result does not change but avoid create nagetive volume.

so,i wannt konw the specific function of these mesh stiffness model

[ghorrocks]

The built in model to do mesh motion uses a diffusion equation to work out the motion of the nodes. This diffusion equation has a diffusivity parameter, which is the mesh stiffness you talk about. This allows you to make some regions of the mesh "stiffer" than others, which if used carefully, can help reduce negative volume element errors.

Also look at the FAQ on this error: https://www.cfd-online.com/Wiki/Ansy..._went_wrong.3F

[cccxi]

the third mesh stiffness model

[cccxi]

thanks for your help