2D plane strain mode vs. 2D axial symmetry stress-strain mode

I am relatively new to structural mechanics and am trying to explore the various application modes of the structural mechanics module. I have used the 2D plane strain mode to obtain the eigen frequencies of the radial and torsional modes of a circular 2D geometry. Is there a way to obatin the same results through the 2D axial symmetry stress-strain mode?

I am also trying to obtain the longitudinal vibration modes of a very long cylinder. Can COMSOL solve for these modes? What is the best suited module to solve for these modes and if possible, what would be the constraints/symmetry conditions to selectively find these modes, without the radial/torsional/flexural modes coming up in the solution set as well?

Thanks!