Effect of Fluid Compressibility on the Transient Response Characteristics of Open-Type Constant Flow Hydrostatic Bearings
Autor: | Liming Xie, Han Chen, Ling Yin, Kuanmin Mao, Longlong Gao, Yikang Du |
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Rok vydání: | 2017 |
Předmět: |
Bulk modulus
Work (thermodynamics) Bearing (mechanical) Materials science Mechanical Engineering 02 engineering and technology Surfaces and Interfaces Mechanics 021001 nanoscience & nanotechnology Surfaces Coatings and Films law.invention Physics::Fluid Dynamics 020303 mechanical engineering & transports 0203 mechanical engineering Mechanics of Materials law Compressibility Lubrication Mass flow rate Transient response Hydrostatic equilibrium 0210 nano-technology |
Zdroj: | Tribology Letters. 66 |
ISSN: | 1573-2711 1023-8883 |
DOI: | 10.1007/s11249-017-0959-9 |
Popis: | The present work describes an experimental and theoretical study to demonstrate the effect of fluid compressibility caused by air in the oil film on the transient performance of an open-type constant flow hydrostatic bearing. An experimental study is conducted to investigate the transient response of the hydrostatic bearing under a step force excitation, and the results demonstrate that the damping coefficient of the bearing decreases with increasing coefficient of oil compressibility when the bearing ascends, but negligible effects of compressibility are observed when the bearing descends. To analyze the mechanism of the compressibility effects due to air in the lubrication, the flow field of oil with air is numerically obtained by solving the incompressible Navier–Stokes equations, with an analytical model describing the dependence of the fluid bulk modulus on the pressure and density. Qualitative agreement between the experimental and numerical results is obtained, which indicates that an increase in the air concentration in the oil, hence a reduction in the bulk modulus of the fluid, results in transient enlargement of the mass flow rate and increased oil film thickness. This finding explains the decrease in the damping coefficient when the bearing ascends. |
Databáze: | OpenAIRE |
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