Ansys DesignModeler – Freeze & Unfreeze

By default DesignModeler merges every new body into the active one. Freeze stops that: a frozen body is excluded from further boolean operations and stays separate, and Unfreeze puts it back into play.

This is the mechanism behind most multi body preparation for CFD. You freeze the parts you want to keep distinct, create the fluid volume around them, and end up with a model whose solid and fluid regions are separate bodies rather than one merged block.

It also controls what the mesher sees. Bodies grouped inside a single part share their nodes at the interfaces, which gives you a conformal mesh across regions. Getting the freeze and grouping right in the geometry stage saves far more time than fixing mismatched interfaces later.