Tangential motion mechanism and reverse hydrodynamic effects of acoustic platform with nonparallel squeeze film

• Published in: Proceedings of the Institution of Mechanical Engineers. Part J, Journal of engineering tribology Journal of engineering tribology, 2019-01, Vol.233 (1), p.194-204
• Main Authors: Bin, Wei, Shaham, Ran, Bucher, Izhak, Luo, Jianbin
• Format: Article
• Language: English
• Subjects: Acoustics; Computational fluid dynamics; Fluid mechanics; Gravitation theory; Levitation; Lubrication; Mathematical models; Mechanical engineering; Reynolds equation; Traveling waves; Viscous fluids
• ISSN: 1350-6501; 2041-305X
• DOI: 10.1177/1350650118774426

In order to explain the reverse hydrodynamic effects on acoustic platform with nonparallel squeeze film, a theoretical model was proposed to evaluate the levitation and movement capacity in this paper. The mechanism of movement and levitation was revealed by the viscous fluid mechanics and dynamic lubrication theory. The transient pressure gradient and steady average velocity were calculated in different deflection angles of nonparallel squeeze film by means of numerical calculation of Reynolds equation. The theoretical results indicated that the platform of nonparallel squeeze film was provided with a bearing and pushing capacity in both normal and tangential directions and it was amazing that the reverse hydrodynamic effects made the levitated plate move into the opposite direction of gravitational tangential component. This proposed theoretical model for acoustic platform with nonparallel squeeze film was different with the original parallel one. Its driving mechanism was the reverse hydrodynamic effect instead of travelling waves. This reverse hydrodynamic effect was proved in the experiments, which could be used in levitation and transport field for precise component in future.