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Purpose: The purpose of this research is to study the dynamic behavior of hydrostatic squeeze film dampers made of four hydrostatic pads, fed through four capillary restrictors with micropolar lubricant. Design/methodology/approach: The modified version of Reynolds equation is solved numerically by the finite differences and the Gauss–Seidel methods to determine the pressure field generated on the hydrostatic bearing flat pads. In the first step, the effects of the pad dimension ratios on the stiffness and damping coefficients are investigated. In the second step, the damping factor is evaluated with respect to the micropolar properties. Findings: The analysis revealed that the hydrostatic squeeze film dampers lubricated with micropolar lubricants produces the maximum damping factor for characteristic length of micropolar lubricant less than 5, while the same bearing operating with Newtonian lubricants reaches its maximum damping factor at eccentricity ratios larger than 0.4. Originality/value: The results obtained show that the effects of micropolar lubricants on the dynamic performances are predominantly affected by the pad geometry and eccentricity ratio. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this paper is to study the influence of different flow regimes on the dynamic characteristics of four-pad hydrostatic squeeze film dampers (SFDs) loaded between pads.Design/methodology/approach A numerical model based on Constantinescu's turbulent lubrication theory using the finite difference method has been developed and presented to study the effect of eccentricity ratio on the performance characteristics of four-pad hydrostatic SFDs under different flow regimes.Findings It was found that the influence of turbulent flow on the dimensionless damping of four-pad hydrostatic SFDs appears to be essentially controlled by the eccentricity ratio. It was also found that the laminar flow presents higher values of load capacity compared to bearings operating under turbulent flow conditions.Originality/value In fact, the results obtained show that the journal bearing performances are significantly influenced by the turbulent flow regime. The study is expected to be useful to bearing designers. [ABSTRACT FROM AUTHOR]

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Significant progress in turbo-machinery’s speed is made recently. To cope with that; many fluids having large differences in rheological properties are introduced as lubricant in hydrostatic bearing systems. The present study aims to improve the understanding of the pressure patterns within hydrostatic bearing flat pads according to different parameters. The main ones are the squeeze film velocity, the feeding pressure and the fluid viscosity. To consider efficiently, the influence of the turbulent and inertia effects numerical simulation are based on transient Navier-Stokes equations. The results of the present study confirm many patterns already mentioned by other authors, and also showed different flow behaviour in terms of vortex evolution according to the studied parameters combinations. [ABSTRACT FROM PUBLISHER]