Dynamic Characteristics of Air Cycle Machine Rotor System

Abstract

Parameters optimization in the critical speed region has the important influence on operational stability of an air cycle machine. Effects of bearing stiffness and unbalanced exciting force on critical speed and response characteristics are investigated by the modal method and harmonic response analysis. Resonance separation phenomenon in the critical speed region is analyzed in detail. When difference exists in the phase of unbalanced exciting force, resonance separation appears in the conical whirling speed region. The characteristics after resonance separation are closely related to the phase difference value and amplitude of unbalanced exciting force. The paper provides theoretical and experimental foundations for resonance separation analysis and also provides data support for dynamic balance and dynamic design of the rotor system.

Effect of the Supports’ Positions on the Vibration Characteristics of a Flexible Rotor Shafting

“…Kumar and Somnath [10] theoretically studied the effects of different bearing lengths, rotor speeds, and unbalanced forces reported in the literature on the dynamic characteristics of rotor-bearing systems. Generally, the effects of bearing stiffness on the critical velocity and vibration response characteristics of shafting systems have been widely investigated [11][12][13][14], as well as the methods to optimize the bearing stiffness, damping, length, gap, and diameter to improve the overall stability of a shafting [15][16][17]. Yücel and Saruhan [18] also used the Taguchi method to test the vibration of a rotor system under different coupling configurations, disk positions, and speeds in order to determine the combination of parameters that minimize deformation due to vibration.…”