Publications associées à Lubrifiant (mécanique)

Computational fluid dynamics simulations of the heat transfer properties of graphene-based nanolubricants and application to hydrodynamic lubrication

In this paper, we consider experimental data available for graphene-based nanolubricants to evaluate their convective heat transfer performance by means of computational fluid dynamics (CFD) simulations. Single-phase models with temperature-dependent prope ...

Aip Publishing2024

Influence of Viscous Lubricant on Nucleation and Propagation of Frictional Ruptures

Marie Estelle Solange Violay, François Xavier Thibault Passelègue, Federica Paglialunga

Fluids are pervasive in the Earth's crust and saturate fractures and faults. The combination of fluids and gouge layers developing along faults can generate fluids of different viscosities. Such viscous fluids were found to influence the reactivation, fric ...

2023

Thermal management for gas lubricated, high-speed turbomachinery

Jürg Alexander Schiffmann, Luis Eric Olmedo Ocampo, Wei Liu, Wanhui Liu

High-speed turbomachinery is commonly designed to achieve high power densities. Limited space for active cooling results in a challenging thermal management. A thermal modeling approach leveraging modern declarative programming capabilities is presented, y ...

2023

Modeling the origins of adhesive wear across scales

Son-Jonathan Pham-Ba

Friction and wear occur at every interface between solid materials. In the design of mechanical devices, it is desirable to be able to quantify and control the amount of friction and wear, as well as predict their evolution with time. ``Tribology'' is the ...

EPFL2022

The Role of Geometrical Parameters in the Lubrication of the Swiss Lever Escapement

Stefano Mischler, Alejandro Roda Buch, Sandra Guadalupe Maldonado

The lubrication regimes of a contact pair escapement-ruby pallet of a Swiss lever escapement have been investigated combining the theory of fluid lubrication with a well-established kinematic and inverse dynamic multibody model. The kinematic analytical re ...

2021

A Simple Mechanistic Model for Friction of Rough Partially Lubricated Surfaces

Jean-François Molinari, Tobias Brink, Gianluca Costagliola, Julie Richard

We report experimental measurements of friction between an aluminum alloy sliding over steel with various lubricant densities. Using the topography scans of the surfaces as input, we calculate the real contact area using the boundary element method and the ...

2021

A lubricated tribocorrosion model incorporating surface roughness

Stefano Mischler, Shoufan Cao

This study presents an improvement of an existing tribocorrosion model developed for passive CoCrMo alloys. This model is based on an empirical formalism established by Duncan Dowson in his pioneering works on the relation between wear and elasto-hydrodyna ...

2021

Adhesive wear regimes on rough surfaces and interaction of micro-contacts

Jean-François Molinari, Son-Jonathan Pham-Ba

We develop an analytical model of adhesive wear between two unlubricated rough surfaces, forming micro-contacts under normal load. The model is based on an energy balance and a crack initiation criteria. We apply the model to the problem of self-affine rou ...

2021

Tribological properties of gold matrix composite coatings with carbon nanocapsules containing ionic liquid lubricants

Stefano Mischler, Anna Neus Igual Muñoz

Self-lubricating, gold matrix composite coatings were produced by electrochemical codeposition of carbon nanocapsules filled with ionic liquid (IL) from a colloidal galvanic bath on a nickel electrode. The tribological response of the composite coatings wa ...

ELSEVIER2020

Tribological Approach to the Watch Movements

Valentine Agnès Madeleine Magnin

Mechanical watches are complex and sensitive systems that have to maintain a faultless precision over their lifetime. However, this precision can be altered by disturbances occurring during the functioning time, such as friction, lubricant drying, or wear, ...

EPFL2020

Optimization of a Py-GC/MS method for silicone -based lubricants analysis

Christophe Roussel, Céline Burnier

Condom evidence can be analysed using several analytical techniques, such as FTIR, MALDI-MS or DART-TOF-MS, but the only one that was used on real samples for transfer and persistence studies in the context of sexual assault or rape cases was Py-GC/MS. How ...

2020

Tribocorrosion of a CoCrMo alloy in sulfuric acid - Glycerol mixtures

Stefano Mischler, Shoufan Cao

This work reports on the tribocorrosion properties of a CoCrMo alloy sliding under imposed passive potential against alumina in sulfuric acid-glycerol mixtures exhibiting different viscosities and thus, in principle, lubrication properties. As expected, we ...

ELSEVIER SCIENCE SA2020

Influence of Bovine Serum Albumin (BSA) on the Tribocorrosion Behaviour of a Low Carbon CoCrMo Alloy in Simulated Body Fluids

Stefano Mischler, Shoufan Cao, Choshun Yoneyama

Tribocorrosion, as the interaction between mechanical wear and electrochemical corrosion, has been found to be the main problem causing the failure and limiting the lifetime of metal-on-metal artificial hip joints. Better understanding of the tribocorrosio ...

2020

Boosting contact sliding and wear protection via atomic intermixing and tailoring of nanoscale interfaces

Reuben Yeo Jueyuan

Friction and wear cause energy wastage and system failure. Usually, thicker overcoats serve to combat such tribological concerns, but in many contact sliding systems, their large thickness hinders active components of the systems, degrades functionality, a ...

American Association for the Advancement of Science (AAAS)2019

Film thickness distribution in gravity-driven pancake-shaped droplets rising in a Hele-Shaw cell

François Gallaire, Gioele Mariano Nicolò Balestra, Nicolas Igor Jacques Kofman, Lailai Zhu, Isha Shukla

We study here experimentally, numerically and using a lubrication approach, the shape, velocity and lubrication film thickness distribution of a droplet rising in a vertical Hele-Shaw cell. The droplet is surrounded by a stationary immiscible fluid and mov ...

Cambridge University Press2019

Tribological response of multilayered gold nickel coating deposited on fine turned surfaces

Stefano Mischler, Valentine Agnès Madeleine Magnin

Gold coating are widely used in industry due to their corrosion resistance, electrical conductivity and low contact resistance. However, friction and wear can limit their functionality and lifetime. This study addresses the degradation of a commercial fine ...

ELSEVIER SCIENCE SA2019

Thin Gas Film Isothermal Condensation in Aerodynamic Bearings

Jürg Alexander Schiffmann, Eliott Philippe Guenat

High-speed small-scale turbomachinery for waste heat recovery and vapor compression cycles is typically supported on gas-lubricated bearings operating close to the saturation conditions of the lubricant. Under particular conditions, the gas film might loca ...

2019

Flexible support and enhanced groove geometries for gas lubricated bearings

Philipp Kaspar Bättig

Gas lubricated Herringbone-Grooved Journal Bearings (HGJB) are a promising solution to support high-speed rotors in oil-free turbo-machinery due to their compactness, relatively low losses, no need for lubrication and low wear. Gas lubricated bearings, how ...

EPFL2019

Tribological and tribocorrosion behavior of nickel sliding against oxide ceramics

Stefano Mischler, Anna Neus Igual Muñoz, Shoufan Cao, Junxiao Du

Nickel is widely used as a coating material in electroplating because of its good corrosion and wear resistance even at high temperature. Tribocorrosion has been identified as one of the main degradation mechanisms of nickel. This study evaluated the tribo ...

ELSEVIER SCIENCE SA2019

Miniaturized tube fixed plug drawing: determination of the friction coefficients and drawing limit of 316 LVM stainless steel

Jean-Marie Drezet, Stefano Mischler, Nicolas Paul Henry Chobaut, Bastien De Marco, Vance Nguyen, Stéphane Dobler

Tube drawing with a ﬁxed plug is investigated experimentally and numerically in order to optimise an industrial pass sequence. Tube drawings are performed on a laboratory drawing bench equipped with force, displacement and temperature sensors. The drawing ...

2018