Calculation of Tilting Pad Bearing Forces
Description
In the field of rotor dynamics, developing dynamic models is essential for analyzing the vibrations of different types of machines under various operating conditions. These models enable early fault detection and facilitate predictive maintenance, thus extending the system’s lifespan and reducing unplanned downtime. However, modeling vertical rotors presents additional challenges. Unlike hori- zontal rotors, the shaft position in vertical rotors constantly varies, complicating numerical simulations. Furthermore, in the case of tilting-pad bearings, which are most commonly used in this configuration, no model is available that accurately estimates the hydrodynamic forces, which significantly influence rotor motion. In this study, a new methodology was developed to determine the dynamic behavior of a vertical rotor. To achieve this, a new model was proposed to describe the dynamic behavior of tilting-pad bea- rings. Expressions were formulated to calculate the hydrodynamic force in these bearings based on the geometry and fluid behavior. A formula was developed to determine the oil film thickness, allowing for a more accurate solution of the Reynolds equation.
Files
Steps to reproduce
1) The MATLAB programs Espesor_NF and Cambio_cord_ang2_eta are used to calculate the oil film thickness in tilting pad bearings. To verify that these programs work correctly, first create a CAD model of a large-scale tilting pad bearing. Espesor_NF calculates the oil film thickness, while Cambio_cord_ang2_eta computes the variation between the reference angles (Theta and Theta-prime, as defined in the paper). 2) The file CotV2.rar contains the necessary programs to generate the spectrum. 3) The remaining programs are designed to obtain the bearing orbits.