Solving a nonlinear problem for a one-sided dynamically loaded sliding thrust bearing

P. E. Fedotov ; N. V. Sokolov

Izvestiya VUZ. Applied Nonlinear Dynamics, Tome 32 (2024) no. 2, pp. 180-196

Résumé

The purpose of this study is to propose an efficient numerical method for solving the inverse nonlinear problem of the movement of the compressor rotor collar in a fluid film thrust bearing. Methods. A periodic thermoelastohydrodynamic (PTEHD) mathematical model of hydrodynamic and thermal processes in a bearing is constructed under the condition of the rotor collar motion. Within the framework of the model, an inverse nonlinear problem of determining the position of the collar under a given external load is formulated. An iterative solution method is proposed, which utilizes the solution of the direct problem. To reduce computational costs, a modified Dekker-Brent method is employed in conjunction with a modified Newton's method. Results. Numerical experiments have been conducted, demonstrating the effectiveness of the proposed approaches. The suggested methods significantly reduce the required computational resources by minimizing the number of calls to the target function in the optimization problem. A software suite has been developed that allows for the calculation of the nonlinear system of rotor motion under various physical and geometric parameters. Conclusion. An efficient set of numerical methods for solving the inverse nonlinear problem of the motion of the rotor collar in the compressor fluid film thrust bearing is proposed. The method's effectiveness lies in substantial savings of computational resources. The method's efficiency has been demonstrated in numerical experiments.

Détail

Keywords: fluid film thrust bearing, differential equations, inverse nonlinear problem, zeroin, Dekker-Brent method, Newton's method