Neural network surrogate model analysis of couple stress squeeze film flow with slip velocity and piezo-viscous effects over rough circular plates
Squeeze-film lubrication plays a crucial role in enhancing the performance, reliability, and service life of tribological components operating under high loads and varying lubrication conditions. This study investigates the squeeze-film lubrication characteristics of rough circular plates lubricated with a pressure-dependent viscous couple-stress fluid under slip velocity. A modified Reynolds equation is developed by incorporating Stokes’ couple stress fluid theory, the Barus pressure–viscosity relationship, slip boundary conditions, and Christensen’s stochastic surface roughness model. The governing equation is analyzed using a Neural network surrogate model (NNSM) to efficiently predict lubrication performance. The effects of the couple stress parameter, pressure–viscosity parameter, slip velocity, and surface roughness on dimensionless pressure, loadcarrying capacity, and squeeze-film time are examined through analytical and numerical analyses. Results indicate that increasing the couple stress parameter enhanced pressure generation, load-carrying capacity, and squeeze-film duration, whereas increasing slip velocity generally reduced pressure and load-carrying capacity. Pressure-dependent viscosity significantly affects pressure distribution and load-supporting capability, while surface roughness produced distinct effects depending on its statistical orientation. The novelty of this work lies in integrating the NNSM with a lubrication model that simultaneously accounts for couple-stress fluid behavior, pressure-dependent viscosity, slip velocity, and surface roughness. The proposed approach provides an efficient method for predicting lubrication characteristics and offers valuable insights for the design and optimization of bearings, gears, seals, dampers, biomedical devices, and other tribological systems.

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