Innovative design of aerostatic bearings with enhanced dynamic stability inspired by the Laval nozzle principle

Microvibrations caused by airflow self-excitation within pressurized air films significantly degrade the dynamic stability of aerostatic bearings. However, effectively controlling supersonic flow velocity, which is critical for suppressing the turbulent airflows that cause this self-excitation, remains a significant challenge in the current designs of aerostatic bearings. To address this gap, a novel aerostatic restrictor inspired by the Laval nozzle principle is proposed to enhance the dynamic stability of bearings by decelerating supersonic pressurized airflows. Computational fluid dynamics (CFD) simulations are conducted to elucidate the underlying mechanism by which the proposed restrictor improves performance (i.e., by suppressing turbulent airflows by mitigating adverse pressure gradients). On the basis of the CFD simulation results, the key geometrical parameters of the newly designed restrictor are identified. The effectiveness of the proposed restrictor is evaluated through experimental testing, with the results indicating that it achieves improved dynamic stability and reduced vibration amplitude compared with a conventional aerostatic restrictor design. This work is expected to advance the theory of restrictor design by enhancing the dynamic stability of aerostatic bearings.