Thermo-hydrodynamic behaviour of a thin lubricant film

An approach utilizing the automodel properties in describing the hydrodynamic behaviour of counter-current columns has been extended to regularly stacked beds. Two new kinds of the packing have been investigated: The so-called K-packing, developed in the German Democratic Republic and the Cellular packing, developed in Poland. The results of experiments have been presented in the form of plots of the normalized liquid hold-up, hp, versus the normalized liquid velocity, Ql, and two empirical correlations. A comparison with previous results with randomly packed counter-current trickle bed columns has also been made.

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Tribological characteristics of MoS2–Nb solid lubricant film in different tribo-test conditions

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2008.08.048 ◽

2008 ◽

Vol 203 (5-7) ◽

pp. 766-770 ◽

Cited By ~ 35

Author(s):

Ihsan Efeoglu ◽

Özlem Baran ◽

Fatih Yetim ◽

Sabri Altıntaş

Keyword(s):

Solid Lubricant ◽

Lubricant Film ◽

Tribological Characteristics ◽

Test Conditions

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Influences of Recess Geometry and Restrictor Dimension on Flow Patterns and Pressure Distribution of Hydrostatic Bearings

Volume 5: Turbo Expo 2007 ◽

10.1115/gt2007-28219 ◽

2007 ◽

Cited By ~ 2

Author(s):

Cheng-Hsien Chen ◽

Yuan Kang ◽

Yeon-Pun Chang ◽

De-Xing Peng ◽

Ding-Wen Yang

Keyword(s):

Pressure Distribution ◽

Stokes Equations ◽

Flow Patterns ◽

Lubricant Film ◽

Navier Stokes ◽

Width Ratio ◽

Navier Stokes Equations ◽

Hydrostatic Bearing ◽

Lubricant Flow ◽

Land Width

This paper studies the influences of recess geometry and restrictor dimensions on the flow patterns and pressure distribution of lubricant film, which are coupled effects of hybrid characteristics of a hydrostatic bearing. The lubricant flow is described by using the Navier-Stokes equations. The Galerkin weighted residual finite element method is applied to determine the lubricant velocities and pressure in the bearing clearance. The numerical simulations will evaluate the effects of the land-width ratio and restriction parameter as well as the influence of modified Reynolds number and the jet-strength coefficient on the flow patterns in the recess and pressure distribution in lubricant film. On the basis of the simulation drawn from this study, the simulated results are expected to help engineers make better use of the design of hydrostatic bearing and its restrictors.

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The hydrodynamic behaviour of biologically inspired bristled shark skin vortex generator in submarine

Materials Today Proceedings ◽

10.1016/j.matpr.2021.02.471 ◽

2021 ◽

Author(s):

Elango Natarajan ◽

Lídio Inácio Freitas ◽

Goh Rui Chang ◽

Ammar Abdulaziz Majeed Al-Talib ◽

C.S. Hassan ◽

...

Keyword(s):

Vortex Generator ◽

Biologically Inspired ◽

Shark Skin ◽

Hydrodynamic Behaviour

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A Numerical Study on Heat Transfer and Lubricant Depletion on an Anisotropic Multilayer Hard Disk

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.232.770 ◽

2012 ◽

Vol 232 ◽

pp. 770-774

Author(s):

Yan Zeng ◽

Xiao Yang Huang ◽

Wei Dong Zhou ◽

Sheng Kai Yu

Keyword(s):

Heat Transfer ◽

Laser Power ◽

Numerical Study ◽

Disk Surface ◽

Lubricant Film ◽

Multilayer Structures ◽

Lubricant Depletion ◽

Thermal Anisotropy ◽

Anisotropy Effect ◽

Higher Temperature

This paper presents a numerical investigation on the effect of thermal anisotropy of the top layer alloy on heat transfer and lubricant depletion on the disk surface in a heat-assisted magnetic recording (HAMR) system. The disk consists of multilayer structures and a thin layer of lubricant on the top surface. Cases under different laser powers and initial lubricant film thicknesses are examined. The top-layer alloy thermal anisotropy does show non-negligible effect on the heat transfer and lubricant depletion. With the top-layer alloy being more anisotropic, higher temperature increase and lager lubricant depletion can be observed on the disk surface. The results also show that the thermal anisotropy effect is more significant under a lower laser power but nearly keeps no much difference under different initial lubricant film thicknesses. Thus it is of importance to include the thermal anisotropy effect of the top-layer Co-alloy when simulating the heat transfer and lubricant depletion in practical multilayer HMAR systems, especially for the cases under the condition of lower laser power, as the effect cannot be neglected under such conditions.

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High-Speed Friction Measurements for a Molecularly Thin Lubricant Film Using a Fiber Wobbling Method

IEEE Transactions on Magnetics ◽

10.1109/tmag.2012.2194990 ◽

2012 ◽

Vol 48 (11) ◽

pp. 4467-4470 ◽

Cited By ~ 2

Author(s):

Shintaro Itoh ◽

Kenji Fukuzawa ◽

Koki Imai ◽

Koki Ishii ◽

Hedong Zhang

Keyword(s):

High Speed ◽

Lubricant Film ◽

Molecularly Thin Lubricant ◽

Friction Measurements

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Model and experiments to determine lubricant film formation and frictional torque in aircraft landing gear pin joints

Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology ◽

10.1177/1350650111434247 ◽

2012 ◽

Vol 226 (4) ◽

pp. 315-327 ◽

Cited By ~ 3

Author(s):

J Zhu ◽

S Pugh ◽

RS Dwyer-Joyce

Keyword(s):

Film Formation ◽

Landing Gear ◽

Lubricant Film ◽

Frictional Torque ◽

Aircraft Landing ◽

Aircraft Landing Gear

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Heat Transfer Analysis of Laminar Pulsating Flow in a Rectangular Channel Using Infrared Thermography

Journal of Heat Transfer ◽

10.1115/1.4052686 ◽

2021 ◽

Author(s):

Richard Blythman ◽

Sajad Alimohammadi ◽

Nicholas Jeffers ◽

Darina B. Murray ◽

Tim Persoons

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Analytical Solution ◽

Local Time ◽

Rectangular Channel ◽

Pulsating Flow ◽

Time Dependent ◽

Heat Transfer Analysis ◽

Flux Boundary Condition ◽

Hydrodynamic Behaviour

Abstract While numerous applied studies have successfully demonstrated the feasibility of unsteady cooling solutions, a consensus has yet to be reached on the local instantaneous conditions that result in heat transfer enhancement. The current work aims to experimentally validate a recent analytical solution (on a local time-dependent basis) for the common flow condition of a fully-developed incompressible pulsating flow in a uniformly-heated vessel. The experimental setup is found to approximate the ideal constant heat flux boundary condition well, especially for the decoupled unsteady scenario where the amplitude of the most significant secondary contributions (capacitance and lateral conduction) amounts to 1.2% and 0.2% of the generated heat flux, respectively. Overall, the experimental measurements for temperature and heat flux oscillations are found to coincide well with a recent analytical solution to the energy equation by the authors. Furthermore, local time-dependent heat flux enhancements and degradations are observed to be qualitatively similar to those of wall shear stress from a previous study, suggesting that the thermal performance is indeed influenced by hydrodynamic behaviour.

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