Reply To: Scaling down a Geometry

[Rob]

In Fluent we can scale the mesh to change the overall dimension. Common usage is when mm/m/km get muddled in the CAD or someone builds a CAD model in inches. The cell count remains the same and the cell size scales with the mesh. 

Changing the scale may also alter the results; especially if residence time or flow regime changes. If mass flow isn't scaled it definitely will! 

Because the cell count is unchanged the RAM usage is also unchanged. Time step will scale with the domain, but flow residence time may not (that's down to how you scale the boundary conditions) so that could alter the overall run time could reduce. Not a question I can really answer as there are too many variables for a generic answer, and I'd need too much information to be specific.