Comportamento transiente de máquinas rotativas

Abstract

This work deals with rotordynamic study in transient motion. The speed of the rotor is considered variable from the rest until the operation speed and the system response, in time domain, is calculated during this interval. Linear and exponencial functions are considered for the speed of rotation. The rotor is modeled using the transfer matrix method and the equation of motion of the system is numerically integrated using the Newmark method. In order to minimize the vibration levei of the rotor in the Crossing of criticai speeds, the following procedures are studied: increase of the rotor acceleration; variation of the bearings stifftiess; use of harmonic forces of control obtained through optimization techniques. The effects of a sudden variation of the rotating mass are also analised.