The thermal capillary migration properties and controlling technique of ferrofluids

Dai, Qingwen; Wang, Jingqiu

doi:10.1177/1350650117698630

Cited by 6 publications

(3 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By solving the balance of these 2 forces, a theoretical expression for the migration velocity can be achieved . In practice, utilisation of specialty lubricants or lubricant additives provides an effective way to either mitigate or impede the thermocapillary migration. Surface energy barriers can also be generated via painting low‐surface energy fluorocarbon compounds around the rubbing or contacting areas to confine the lubricant movement at the desired locations and limit its migration …”

Section: Introductionmentioning

confidence: 99%

The thermocapillary migration on rough surfaces

Dai

Khonsari

et al. 2018

Lubrication Science

Self Cite

View full text Add to dashboard Cite

In tribo‐system, thermal gradients will drive the liquid lubricant to migrate from warm to cold regions, resulting in starved lubrication. This study reports an experimental investigation on the influence of surface topography on the migration behavior of paraffin oil lubricants. Experimental results are provided for specimens treated by polishing, shot‐blasting, and sandpaper grinding techniques. 3D surface parameters of average surface roughness Sa and developed interfacial area ratio Sdr are measured via a 3D optical microscope, and the influences on migration behavior are discussed. Experimental results demonstrate that shot‐blasting process is an effective approach to impede the thermocapillary migration, and that decreasing surface roughness will contribute to the obstruction effect. A particular attention is paid to the inherent correlation of the migration capacity with the contact angle and surface free energy.

show abstract

Section: Introductionmentioning

confidence: 99%

The thermocapillary migration on rough surfaces

Dai

Khonsari

et al. 2018

Lubrication Science

Self Cite

View full text Add to dashboard Cite

show abstract

“…Similar results were obtained for servomotors. Recently, Ke et al and Dai et al investigated the migration of ferrofluids (Fe 3 O 4 nanoparticles in PAO oil) on steel surfaces as a result of an applied temperature gradient [101,102]. Due to lubricant migration, the COF in ball-on-disc experiments increased shortly after the start of the experiment.…”

Section: Applied Research and Potential Applicationsmentioning

confidence: 99%

Thermocapillary lubricant migration on textured surfaces - a review of theoretical and experimental insights

Grützmacher¹,

Jalikop²,

Gachot³

et al. 2021

Surf. Topogr.: Metrol. Prop.

View full text Add to dashboard Cite

Thermocapillary migration in tribological systems such as gearboxes, piston ring-liner assemblies, or bearings can lead to lubricant starvation and, consequently, to severe damages. Due to surface tension gradients induced by local temperature gradients on the frictionally heated surface, lubricant may flow out of the hotter contact zone to colder adjacent regions. In order to manipulate lubricant migration, several approaches exist to create migration barriers or to guide lubricant in a well-defined way back into the contact. These approaches are either based upon surface topography (designed surface textures) and/or surface chemistry (designed chemical patterns). In this review article, the state-ofthe-art regarding thermocapillary migration is summarized from a theoretical and experimental point of view. After a brief introduction, theoretical models are presented to introduce the underlying theory of droplet spreading and thermocapillary migration. Subsequently, the influence of surface textures and chemical patterns on thermocapillary migration and the possibilities to use these approaches to manipulate lubricant migration are discussed. After addressing applied research in this field and potential applications, current challenges and future research directions are presented before closing with general conclusions.

show abstract

“…In addition, the influence of working conditions and structural parameters, as well as shear stress with a wider range of values applied on the interface of the solid surface and liquid film on the performance of the tribo-pair with a hydrodynamic groove can be further explored. Significantly, negative shear stress, possibly achieved using a temperature gradient [53,54], magnetic field [55], or electric field [56,57], can be applied to the liquid while the solid surface remains superslippery. This work provides guidelines for further enhancing the technical level of microelectromechanical systems, liquid film seals, liquid lubricated bearings, and other relevant fields based on microflow theory.…”

Section: Introductionmentioning

confidence: 99%

Mechanism of no-wear super-slip design of tribo-pair in load lifting and friction reduction

Hu¹,

Wang²,

Yang³

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

The concept of “super-slip design” is used to investigate the influence of multiple factors on the opening and frictional forces of a tribo-pair with microscale grooves. The results demonstrate that significantly improving the load-carrying capacity and reducing the viscous friction can be simultaneously realised by super-slip modification of the bottom surface of the hydrodynamic groove as a result of the joint action of the super-slip surface, groove geometrical parameters, and operating conditions. This is expected to further enhance the load-carrying capacity and reduce friction by applying shear stress on the interface of the liquid film and superslippery surface of the groove bottom. The superslippery surface does not fail because of rubbing, and the logical relationship between the performance parameters and groove depth changes unusually under this design.

show abstract

The thermal capillary migration properties and controlling technique of ferrofluids

Cited by 6 publications

References 34 publications

The thermocapillary migration on rough surfaces

The thermocapillary migration on rough surfaces

Thermocapillary lubricant migration on textured surfaces - a review of theoretical and experimental insights

Mechanism of no-wear super-slip design of tribo-pair in load lifting and friction reduction

Contact Info

Product

Resources

About