hi guys;
I can't get the assial-symmetrical model required: I have a charge of variable radius, with a predetermined charge density and I am at a certain distance from it; I have a spire in a certain position on the axis and I have to ask him that the field in another position is equal to the value assigned by us; my unknown is precisely the height of the spire; how can I, regardless of the expressed problem, vary a certain unknown in a comsol program? I also read the optimization manual but I can't make the model; could you help me at least to understand how to set the variation of an assigned variable? Thank you very much kind regards.