Estimation of Energy Efficiency of Oscillations of Rotors on Radial Fluid Film Bearings

Abstract

The following parameters have the most influence on the dynamics of a high-speed turbomachine's rotor system: mass and stiffness distribution of a rotor; damping properties of the materials of rotor's elements; location of bearings, sealings, and dampers; type, design, and operational conditions of bearings, sealings, and dampers; mass and inertia characteristics of machine's housing; and operational conditions of a turbomachine itself. It should be noted that the presence of fluid film bearing complicates the dynamic analysis. It is thus a quite urgent task to search for some rational parameters when a rotor system is under design and preliminary calculation, which in many cases leads to the problems of an optimal parametric design. One of the main yet controversial problems of parametric design in the field of rotor system dynamics is the determination of quality indicators for a particular case of a rotor system. The present paper proposed a criterion based on the efficiency of rotor system's input energy. The analysis of a number of parameters', e.g., values of constant external forces (rotor's mass), varying external forces (imbalance), and types of bearings, influence on this criterion has also been carried out.

On finite element model for hydrodynamic journal bearing with micropolar lubrication

“…In case of bearing with axial lubricantion, the problem becomes nonlinear since condition (10) is replaced by condition (14). In this case, the Newton-Raphson method with the tangent matrix considered above is applied.…”

“…However, the main motivation for this work was the need for intensive calculations of the bearing reactions in problems of finding the optimum energy-efficient rotor trajectories [13][14]. The solution to these problems is conveniently carried out in research environments that have built-in tools in our case, Matlab.…”