Effect of rotating unbalance on nonlinear dynamic response of flexible rotors supported on tilting pad journal bearing

• Published in: Engineering Research Express Vol. 2; no. 4; pp. 45002 - 45016
• Main Authors: Dixit, Harsh Kumar, Singh, Ajit, Gupta, T C
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.12.2020
• Subjects: nonlinear dynamic analysis; rotating unbalance; tilting pad journal bearing; vertical rotor
• ISSN: 2631-8695; 2631-8695
• DOI: 10.1088/2631-8695/abbadf

Abstract The effect of orientation of rotors and rotating unbalance at disc on the dynamic response of rotor supported by four pad tilting pad journal bearing (TPJB) is studied. The orientation of the rotor taken has a horizontal rotor (HR) and a vertical rotor (VR). The rotor element modeled as the Timoshenko beam element with four degrees of freedom per node. The disc is rigid and it is centrally mounted. The nonlinear forces by the fluid film in tilting pad journal bearing were determined by solving the Reynolds equation along with each pad. The infinite short bearing assumption has taken to find pressure distribution along with pads. Indigenous MATLAB ® code has developed to solve the rotor-TPJB equation. The ODE-15s solver is used to find the related response data of journal and disc centers. Orbits, phase plots, and power spectrums used to analyze the behavior of the system. The sub-synchronous vibrations dominate at lower speeds and high rpm unbalance forces become much significant and overcome bearing fluid film forces causing catastrophically change in response of the system.