Sensitivity analysis of a rotordynamics system with magnetic bearings and internal seal

Diego Alejandro Godoy Diaz¹; Fernando Augusto de Noronha Castro Pinto¹; Thiago Gamboa Ritto¹

¹ UFRJ

doi:10.20906/CPS/COB-2015-0748

Resumo

Gas machine seals with bearing support systems are one of the most important components of common rotating turbomachines. Despite many works are centered on understanding and predicting their rotordynamic characteristics, uncertainties remain in prediction of machinery behavior meaning risks of instability. Industrial turbomachines rotors can reach speeds beyond 15.000 RPM, whereby active magnetic bearings (AMB) become an interesting and achievable solution for supporting radial and thrust rotor forces in these machines. This paper presents a sensitivity analysis and discussion about the rotordynamics of a rotor with two radial AMB and internal seal, using a Jeffcott model with 4 DOF, and a simplified equivalent model for AMB and annular gas seal. For the sensibility analysis has been implemented an algorithm based on the Monte Carlo Methods.

Palavras-chave: Rotordynamics; Annular seal; Sensitivity analysis