Based on the Hamilton Principle, a model of the double-disk and double-span rotor system is established by three journal bearings supported. Due to Hamilton Principle from the energy angle, the rotor system equation of motion form is simple and easy to solve using the Fourth order Runge-Kutta method in MATLAB. The dynamic characteristic of the double-span rotor system are studied with the coupled effect of the nonlinear oil-film force, the nonlinear seal force and the mass eccentric force of disk. The numerical calculation results show that the bifurcation motion of the rotor system is easier to occur at lower rotation speed with the increasing of the seal pressure drop, seal length, disk eccentricity and the reduction of the seal clearance. This modeling and analysis method can be further applied for the multi-span rotor system.

This content is only available via PDF.
You do not currently have access to this content.