Year: 2024
Type: article
Abstract: Developed in this study is a theoretical description of squeeze-film lubrication systems that involve the flexural oscillation of a thin plate near a parallel wall. Such systems were discovered in recent experiments to produce load-bearing attractive forces that are a thousandfold stronger than those generated by rigid oscillators, which typically favour repulsion. Analyses of squeeze-film gas flow driven by a presumed plate deformation reproduce the observed magnification of attractive load capacity, but exhibit serious discrepancies with crucial aspects of the experimental measurements – most importantly, the precise distribution of air pressure along the film. The discrepancies are resolved in this study by accounting for the presence of two-way-coupled fluid–structure interactions whereby the undulations of the plate, modelled here with use of the classical Kirchhoff–Love equation, are affected non-negligibly by the evolving pressure, described by a modified Reynolds lubrication equation that accounts for compressibility. The resulting problem of elastohydrodynamic lubrication is solved with use of perturbation methods that exploit the limit of small oscillation amplitudes. The analysis ultimately provides an explicit expression specifying the attractive load capacity of a squeeze-film system as a function of relevant operating parameters – including, in particular, the amplitude and frequency of the localized excitation force exerted on the plate. The rudimentary theory derived here may be readily generalized to guide the analysis and development of a wide variety of emerging engineering systems that exploit the vibration-induced squeeze-film effect – such as wall-climbing soft robots and contactless grippers.
Source: Journal of Fluid Mechanics
Authors: S. Ramanarayanan, A.L. Sánchez
Institution: University of California San Diego
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,450
OpenAlex ID: W4405591825