Congratulation to Elia Iseli

© 2022 EPFL

© 2022 EPFL

Elia Iseli successfully defend his PhD thesis entitled "Numerical and experimental investigation of spiral-grooved gas journal bearings" on May 24th, 2022.

During his PhD which he did at Fisher Spindel Group AG, in collaboration with Prof. J. Schifmmann (EPFL LAMD), Elia Iseli investigated spiral-grooved gas journal bearings.

The usage of aerodynamic bearings allows the design of compact compressors while guaranteeing a high degree of working fluid purity. Herringbone-grooved gas bearings have the advantages of oil-free operation, long-lifetime, high rotational speeds with relatively low frictional losses, no sealing requirements and avoidance of auxiliary systems. However, for the design of robust gas-bearing supported rotors fast but accurate models are necessary, which need to be validated experimentally.

In the frame of the project, novel models for the herringbone grooved journal bearing are developed in order to resolve the rotating grooves spatially and by considering transient effects. For speeding-up computation time, bearing meta-models are derived, enabling multidimensional regression by applying artificial neural networks. The bearing models are integrated in rotordynamic systems and different rotordynamic modules are introduced. Based on full non-dimensional analysis the models are compared with each other, their limitations presented and finally experimentally validated by means of a modular test rig