Discussion Forum

How do I define a global parameter, in COMSOL 3.5, so that I can use it for creating a part of a geometry, say the thickness of a diaphragm and use it to do a parametric sweep? I would be doing the parametric sweep in relation to the diaphragm thickness to see the change in deflection of the diaphragm with a given force due to different thicknesses. I know in COMSOL 4.1 there is a section under Global Definitions that allows you to define global parameters and then use them in building your geometry. When I try to define global expressions in COMSOL 3.5 it will let me, but then when I try to use them as my dimension inputs it gives me an error saying the global expression is not defined. I can't seem to find what I'm looking for in the COMSOL User's Guide either.