Torsional vibration analysis

Hi,

I need to perform a torsional vibration analysis to determine the torsional eigenfrequencies for a long shaft (30m) with an impeller on the end.

I tried to use a frequency study, but I only get lateral results. Does anybody know which function I can use?

(torsional vibration example: http://www.epi-eng.com/mechanical_engineering_basics/torsional_vibration_intro.htm)

Any help is greatly appreciated.

Regards,

Hein de Groot

SolidworksSimulation