Model size change in ansys
 

I have an simulation where I need to change size of rotor parametrs. Can I, in someway, change the model rotor size in ansys and do a couple of simulations or the only way is to make another model?

In CFX-Pre, you can scale the mesh by a factor. In this way your whole geometry will change in size. You can use different scale factors for different directions.

But if only your rotor should change and the other parts remain the same, then things won't fit anymore and you have to redraw and remesh your model. That;s obvious..

The alternative interpretation to your "model size" is that you want to replace by a coarser, or finer mesh.

In that case, create the new mesh using the same named regions, write your new mesh file using the same name as the previous mesh and use "Reload Mesh". Your old mesh will be replaced and the physics will remain intact.

That is how Workbench uses CFX-Pre behind the scenes to do parametric mesh changes.