Piezo viscous averaged inertia analysis of squeeze film lubrication in annular disks with micropolar fluids

This study investigates the combined influence of piezo-viscous behavior, micropolar fluid characteristics, and averaged inertial effects on squeeze film lubrication between parallel annular disks. The analysis incorporates a nonlinear dependence of viscosity on pressure and includes micropolar parameters to capture microstructural fluid effects. Using an averaged inertia approach, the impact of convective inertia on pressure distribution, load-carrying capacity, and response time is examined. Findings reveal that pressure-dependent viscosity enhances load support compared to the iso-viscous case by resisting inertial momentum spreading. Additionally, increasing the micropolar couple stress parameter can decrease load-carrying capacity when fluid rotation weakens pressure gradients. However, an increase in cross-viscosity and microrotation effects enhance load support. As the micropolar couple stress parameter increases significantly, the results gradually approach classical Newtonian squeeze film behavior, mainly when the annular ring effect is absent. The effectiveness of lubrication systems in aerospace, high-speed rotary machinery, and precision engineering is significantly affected by pressure-dependent viscosity changes and inertial effects. These findings are relevant to these applications.