Robust design optimization of gas-lubricated herringbone grooved journal bearings: Surrogate modeling and experimental validation

This study experimentally validates robust designs for herringbone grooved journal bearings (HGJBs) in micro-turbocompressors, addressing manufacturing deviations that lead to rotor instabilities. Experiments on a Pelton-driven rotor system focused on maximizing the hypervolume (HV) of the feasible operational region and the signal-to-noise ratio (S/N), considering deviations in groove depths and bearing clearances. Robustness was tested at 15 points using various rotor and bushing combinations, compared with non-robust control points emphasizing stability, load capacity, and loss minimization. Results showed strong alignment between surrogate model predictions and experimental data, confirming the model's effectiveness. The successful validation highlights the potential of surrogate model-assisted robust design optimization to enhance HGJB robustness in practical applications.