The nonlinear coupling vibration and bifurcation of a high-speed centrifugal compressor with a labyrinth seal and two air-film journal bearings are presented in this paper. The rotary shaft and disk are modeled as a rigid Jeffcott rotor. Muszynska’s model is used to express the seal force with multiple parameters. For air-film journal bearings, the model proposed by Zhang et al. is adopted to e...

Rotating machinery support design with the aim of reducing the force transmitted to the foundation has significant importance regarding the various applications of these machineries. In this paper presents a rapid approximate method for calculating the optimum support flexibility and damping of flexible rotors to minimize force transmissibility in the vicinity of the rotor first critical speed....

In dynamical systems models from biology to power systems, structural identifiability 4 is an essential step for understanding, probing, and even controlling the dynamical system. When the 5 system input is controllable, structural identifiability can be verified by computing well-established, 6 straightforward conditions. In many applications, however, the system input is stochastic, and these...

Abstract In this study, the coupled torsional–transverse vibration of a propeller shaft system owing to misalignment caused by rotation was investigated. The proposed numerical model is based on modified version Jeffcott rotor model. equation motion describing harmonic vibrations obtained using Euler–Lagrange equations for associated energy functional . Experiments considering different speeds ...

Abstract In previous studies of linear rotary systems with active magnetic bearings, parametric excitation was introduced as an open-loop control strategy. The realized by a periodic, in-phase variation the bearing stiffness. At difference between two eigenfrequencies system, stabilizing effect, called anti-resonance, found numerically and validated in experiments. this work, preliminary result...

Abstract Hydrodynamic journal bearings are used in many applications which involve high speeds and loads. However, they susceptible to oil whirl instability, may cause bearing failure. In this work, a flexible Jeffcott rotor supported by two identical is investigate the stability bifurcations of system. Since closed form for finite forces not exist, nonlinear stiffness damping coefficients repr...

The electromechanical interaction in electric machines induces additional forces between the rotor and stator. To study this interaction, a simple electromechanical model was developed. The mechanical behaviour was modelled by the Jeffcott rotor. The electromagnetic forces were described by a simple parametric model including two electormagnetic variables. The aim of the study was to investigat...