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Sarkar, Chiranjit
Publications (5 of 5) Show all publications
Sarkar, C., Westerberg, L.-G., Höglund, E. & Lundström, S. T. (2018). Numerical simulations of lubricating grease flow in a rectangular channel with and without restrictions. Tribology Transactions, 61(1), 144-156
Open this publication in new window or tab >>Numerical simulations of lubricating grease flow in a rectangular channel with and without restrictions
2018 (English)In: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397X, Vol. 61, no 1, p. 144-156Article in journal (Refereed) Published
Abstract [en]

This article presents numerical simulations of the laminar flow of lubricating greases in a channel with rectangular cross section. Three greases with different consistencies (NLGI grades 00, 1, and 2) have been considered in three different configurations composed of a rectangular channel without restrictions, one rectangular step restriction, and one double-lip restriction. The driving pressure drop over the channel spans from 30 to 250 kPa. The grease rheology is described by the Herschel-Bulkley rheology model, and both the numerical code and rheology model have been validated with analytical solutions and flow measurements using micro-particle image velocimetry.

Place, publisher, year, edition, pages
Taylor & Francis, 2018
National Category
Fluid Mechanics and Acoustics Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Fluid Mechanics; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-61479 (URN)10.1080/10402004.2017.1285090 (DOI)000432222500015 ()
Note

Validerad;2018;Nivå 2;2018-02-01 (rokbeg)

Available from: 2017-01-17 Created: 2017-01-17 Last updated: 2018-06-04Bibliographically approved
Westerberg, L.-G., Sarkar, C., Farré, J., Lundström, S. & Höglund, E. (2017). Lubricating grease flow in a double restriction seal geometry: a Computational Fluid Dynamics approach. Tribology letters, 65(3), Article ID 82.
Open this publication in new window or tab >>Lubricating grease flow in a double restriction seal geometry: a Computational Fluid Dynamics approach
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2017 (English)In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 65, no 3, article id 82Article in journal (Refereed) Published
Abstract [en]

In this paper, numerical simulations of lubricating grease flow in the grease pocket of a double restriction seal geometry using computational fluid dynamics are presented. The grease is treated as a single-phase Herschel–Bulkley fluid with different rheological properties corresponding to NLGI grade 00, 1 and 2. The numerical code and rheology model have been validated with a semi-analytical solution based on flow measurements using microparticle image velocimetry. The flow has been modelled for low and high rotational speeds driving the flow, and elevated temperatures. Also, the evolution of contaminant particles in the grease pocket is investigated. It was found that the flow and velocity distribution in the pocket—and consequently the contaminant particle concentration evolution, is characterized by the shear thinning rheology of the grease. With higher shear rates in the grease and higher temperatures, the grease approaches a more Newtonian type of behaviour leading to a reduced yield and shear thinning characteristics directly affecting the grease ability to transport contaminant particles.

Place, publisher, year, edition, pages
Springer, 2017
National Category
Fluid Mechanics and Acoustics Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Fluid Mechanics; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-63306 (URN)10.1007/s11249-017-0864-2 (DOI)000405488400008 ()2-s2.0-85019554610 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-05-24 (andbra)

Available from: 2017-05-10 Created: 2017-05-10 Last updated: 2018-07-10Bibliographically approved
Westerberg, L.-G., Höglund, E. & Sarkar, C. (2016). Modelling and experimental validation of grease flow. Eurogrease Magazine (4), 17-32
Open this publication in new window or tab >>Modelling and experimental validation of grease flow
2016 (English)In: Eurogrease Magazine, no 4, p. 17-32Article in journal (Other academic) Published
National Category
Signal Processing Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements; Signal Processing
Identifiers
urn:nbn:se:ltu:diva-61057 (URN)
Available from: 2016-12-13 Created: 2016-12-13 Last updated: 2018-03-09Bibliographically approved
Westerberg, L.-G., Höglund, E. & Sarkar, C. (2016). Modelling and experimental validation of lubricating grease flow (ed.). Paper presented at ELGI Annual General Meeting : 16/04/2016 - 19/04/2016. Paper presented at ELGI Annual General Meeting : 16/04/2016 - 19/04/2016.
Open this publication in new window or tab >>Modelling and experimental validation of lubricating grease flow
2016 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

Being able to fully model the flow dynamics of grease, including phase separation, will be highly valuable in the design of lubricated machine elements such as rolling element bearings. Complete models will also be a valuable tool in the process of providing tailor-made greases for different applications. An understanding of the grease flow dynamics enables prediction of grease distribution for optimum lubrication and for the migration of wear- and contaminant particles. In this paper the potential of combined analytical modelling, flow visualizations, and numerical modelling in grease flow dynamics is presented. Specifically, the relation between the rheology of the grease and its impact on the flow motion is of interest in combination with validation of the numerical models in simplified geometries. The numerical models then enable simulations in more complex geometries of particular interest for the grease and bearing industry. It is shown that grease flow is heavily influenced by its non-Newtonian properties and the shear rates in the contact, resulting in distinct regions of yielded and un-yielded grease. Further, the numerical models are shown to match well with experiments and analytical models, enabling numerical models on more complicated geometries.

National Category
Fluid Mechanics and Acoustics Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Fluid Mechanics; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-27623 (URN)11f18ac7-117b-465d-ad80-3db6b169c403 (Local ID)11f18ac7-117b-465d-ad80-3db6b169c403 (Archive number)11f18ac7-117b-465d-ad80-3db6b169c403 (OAI)
Conference
ELGI Annual General Meeting : 16/04/2016 - 19/04/2016
Note
Godkänd; 2016; 20160425 (andbra)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-03-09Bibliographically approved
Westerberg, L.-G., Höglund, E. & Sarkar, C. (2016). On the Flow of Lubricating Greases: a Computational Fluid Dynamics Approach. In: : . Paper presented at STLE Tribology Frontiers Conference, Chicago, Nov. 13-15, 2016.
Open this publication in new window or tab >>On the Flow of Lubricating Greases: a Computational Fluid Dynamics Approach
2016 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Being able to model the flow dynamics of grease is highly valuable in the design of lubricated machine elements such as rolling element bearings. An understanding of the grease flow dynamics enables prediction of grease distribution for optimum lubrication and for the migration of wear- and contaminant particles. In this paper the potential of combined analytical modelling, flow visualizations, and numerical modelling in grease flow dynamics is presented. Specifically, the relation between the rheology of the grease and its impact on the flow motion is of interest in combination with validation of the numerical models in simplified geometries. The numerical models then enable simulations in more complex geometries of particular interest for the grease and bearing industry. It is shown that grease flow is heavily influenced by its non-Newtonian properties and the shear rates in the contact, resulting in distinct regions of yielded and un-yielded grease. Further, the numerical models are shown to match well with experiments and analytical models, enabling numerical models on more intricate geometries in the bearing industry.

National Category
Fluid Mechanics and Acoustics Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Fluid Mechanics; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-61046 (URN)
Conference
STLE Tribology Frontiers Conference, Chicago, Nov. 13-15, 2016
Available from: 2016-12-13 Created: 2016-12-13 Last updated: 2018-03-09Bibliographically approved
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