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Cupillard, Samuel
Publications (10 of 17) Show all publications
Cupillard, S., Cervantes, M. & Glavatskih, S. (2014). Thermohydrodynamic analysis of a journal bearing with a microgroove on the shaft (ed.). Paper presented at . Computational Thermal Sciences, 6(1), 47-57
Open this publication in new window or tab >>Thermohydrodynamic analysis of a journal bearing with a microgroove on the shaft
2014 (English)In: Computational Thermal Sciences, ISSN 1940-2503, E-ISSN 1940-2554, Vol. 6, no 1, p. 47-57Article in journal (Refereed) Published
Abstract [en]

In this study, thermohydrodynamic performance of a journal bearing with a microgroove created on the shaft is analyzed. A plain journal bearing is modeled using a computational fluid dynamics (CFD) software package. Navier-Stokes and energy equations are solved. The rotor-stator interaction is treated by using a computational grid deformation technique. The goal is to examine the pressure/temperature distribution in the bearing film. Results are presented in terms of typical bearing parameters as well as flow patterns. Results are also compared to the bearing with a smooth shaft. The effect induced by a microgroove on pressure distribution is explained for different bearing configurations, eccentricities, and microgroove depths. It is shown that the microgroove produces a local drop in pressure which, averaged over one revolution, decreases the load carrying capacity. The load carrying capacity is further decreased by using deeper microgrooves. With thermal effects considered, the microgroove carries more cold lubricant into the warmest regions of the bearing. This effect, more pronounced with deeper microgrooves, is due to a global flow recirculation inside the microgroove, which improves mixing

National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-4703 (URN)10.1615/ComputThermalScien.2014005894 (DOI)2-s2.0-84897783176 (Scopus ID)2af836ae-788a-453f-bbd7-79b2b8ebdb0c (Local ID)2af836ae-788a-453f-bbd7-79b2b8ebdb0c (Archive number)2af836ae-788a-453f-bbd7-79b2b8ebdb0c (OAI)
Note
Validerad; 2014; 20140422 (johsod)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Cervantes, M., Cupillard, S., Bance, K. & Kokkolaras, M. (2012). Shape optimization of a 3D slider with dimples (ed.). Journal of Civil Engineering and Architecture, 6(12), 1599-1607
Open this publication in new window or tab >>Shape optimization of a 3D slider with dimples
2012 (English)In: Journal of Civil Engineering and Architecture, ISSN 1934-7359, E-ISSN 1934-7367, Vol. 6, no 12, p. 1599-1607Article in journal (Refereed) Published
Abstract [en]

Sliding contacts in laminar flow regimes have been investigated extensively in recent years. The results indicate the possibility to increase load carrying capacity in a slider bearing for more than 10% with the addition of dimples. Parametric studies have been performed to determine optimal size and position, with emphasis in the optimal shape and position of the dimple for an operating condition. In this article, the numerical analysis of a 2D textured slider bearing with a dimple is initially considered with an isothermal laminar fluid. Position, depth, width and convergence ratio are optimized, the results demonstrate the importance of the width and convergence ratio to increase load. Then, the numerical analysis of a 3D textured slider bearing with fore-region and extended channels at the outlet and on the sides of a pad is considered. The simulations are also carried out for a laminar isothermal flow. Three dimples are considered and their depth is optimized.

National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-4361 (URN)10.17265/1934-7359/2012.12.001 (DOI)24cd5e8d-37e5-4547-b318-7d4588bc8172 (Local ID)24cd5e8d-37e5-4547-b318-7d4588bc8172 (Archive number)24cd5e8d-37e5-4547-b318-7d4588bc8172 (OAI)
Note

Validerad; 2013; 20130411 (cervante)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2020-03-19Bibliographically approved
Cervantes, M., Cupillard, S. & Kokkolaras, M. (2011). Shape optimisation of a 3D slider with a dimple (ed.). Paper presented at International Symposium on Transport Phenomena : 08/11/2011 - 11/11/2011. Paper presented at International Symposium on Transport Phenomena : 08/11/2011 - 11/11/2011.
Open this publication in new window or tab >>Shape optimisation of a 3D slider with a dimple
2011 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

Sliding contacts under laminar regime have been extensively investigated under the last years. The results indicate the possibility to increase load carrying capacity in a slider bearing with more than 10% with the addition of dimples. Parametric studies have been performed on size and position, while an optimisation to determine the true potential have not yet been examined. Of interest is the optimal shape of the dimple function of the operating condition and position. In the present work, the numerical analysis of a 2D textured slider bearing with fore-region is initially considered with an isothermal laminar fluid. One dimple is considered and the shape optimized for different operating conditions and positions. Then, the numerical analysis of a 3D textured slider bearing with fore-region and extended channels at the outlet and on the sides of a pad is considered with a temper-ature dependent fluid. The simulations are also carried out for a laminar flow. One dimple is considered and the shape optimized for different operating conditions and positions.

National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-34375 (URN)88d9367e-c6be-4d1d-8fba-7e2e38434bdc (Local ID)88d9367e-c6be-4d1d-8fba-7e2e38434bdc (Archive number)88d9367e-c6be-4d1d-8fba-7e2e38434bdc (OAI)
Conference
International Symposium on Transport Phenomena : 08/11/2011 - 11/11/2011
Note
Godkänd; 2011; 20111113 (cervante)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Cupillard, S., Cervantes, M. & Glavatskih, S. (2011). Thermohydrodynamic analysis of a journal bearing with a microgroove on the shaft (ed.). Paper presented at International Symposium on Transport Phenomena : 08/11/2011 - 11/11/2011. Paper presented at International Symposium on Transport Phenomena : 08/11/2011 - 11/11/2011.
Open this publication in new window or tab >>Thermohydrodynamic analysis of a journal bearing with a microgroove on the shaft
2011 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

In this study, thermohydrodynamic performance of a journal bearing with a microgroove created on the shaft is analysed. A plain journal bearing is modelled using a computational fluid dynamics (CFD) software package. Navier-Stokes and energy equations are solved. The rotor-stator interaction is treated by using a computational grid deformation technique. Results are presented in terms of typical bearing parameters as well as flow patterns. Results are also compared to the bearing with a smooth shaft. The effect induced by a microgroove on pressure distribution is explained for different bearing configurations, eccentricities and microgroove depths. It is shown that the microgroove produces a local drop in pressure which, averaged over one revolution, decreases the load carrying capacity. The load carrying capacity is further decreased by using deeper microgrooves. With thermal effects considered, the microgroove carries more cold lubricant into the warmest regions of the bearing. This effect, more pronounced with deeper microgrooves, is due to a global flow recirculation inside the microgroove, which improve mixing

National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-38845 (URN)d5c0a664-f793-4534-a346-710199af7c21 (Local ID)d5c0a664-f793-4534-a346-710199af7c21 (Archive number)d5c0a664-f793-4534-a346-710199af7c21 (OAI)
Conference
International Symposium on Transport Phenomena : 08/11/2011 - 11/11/2011
Note
Godkänd; 2011; 20111113 (cervante)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2017-11-25Bibliographically approved
Cervantes, M. & Cupillard, S. (2010). 3D thermodynamic analysis of a turbulent textured slider (ed.). Paper presented at International Symposium on Transport Phenomena : 02/11/2010 - 05/11/2010. Paper presented at International Symposium on Transport Phenomena : 02/11/2010 - 05/11/2010.
Open this publication in new window or tab >>3D thermodynamic analysis of a turbulent textured slider
2010 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

Sliding contacts under laminar regime have been extensively investigated under the last years. The results indicate the possibility to increase load carrying capacity in a slider bearing with more than 10%. The effect of dimples on a slider bearing under a turbulent regime has not yet been investigated. It is the object of the present study. The numerical analysis of a 3D textured slider bearing with fore-region and extended channels at the outlet and on the sides of a pad is considered with a temperature dependent fluid, 2 different types of dimple shape and different operating conditions. The simulations are carried out for a turbulent flow (Re=4.4•10^3- 15•10^3) using Detached Eddy Simulation. The results indicate no gain on the load carrying capacity with the dimple shapes (rectangular and oblique) investigated. A higher operating temperature is found in the presence of dimples.

National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-27600 (URN)1177669d-c5ed-4b47-bda0-bfb77cc051d8 (Local ID)1177669d-c5ed-4b47-bda0-bfb77cc051d8 (Archive number)1177669d-c5ed-4b47-bda0-bfb77cc051d8 (OAI)
Conference
International Symposium on Transport Phenomena : 02/11/2010 - 05/11/2010
Note
Godkänd; 2010; 20120926 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Cupillard, S., Glavatskih, S. & Cervantes, M. (2010). Inertia effects in textured hydrodynamic contacts (ed.). Paper presented at . Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, 224(8), 751-756
Open this publication in new window or tab >>Inertia effects in textured hydrodynamic contacts
2010 (English)In: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, ISSN 1350-6501, E-ISSN 2041-305X, Vol. 224, no 8, p. 751-756Article in journal (Refereed) Published
Abstract [en]

A flow analysis is carried out for a parallel textured slider to investigate the role of fluid inertia. Numerical simulations are performed for a laminar, two-dimensional, steady and isothermal flow. Stokes solutions are compared with Navier-Stokes solutions at the same Reynolds number. A range of texture depths is analysed. It is shown that there is an optimum value of texture depth that provides maximum load-carrying capacity. It is also shown that there is a critical depth value. Inertia has a negative effect on the load-carrying capacity for depths higher than the critical value, whereas it has a positive effect for lower depths. For a given texture depth, these effects are amplified as the Reynolds number increases. The global effect of inertia is positive when a realistic configuration of a parallel textured slider with a fore-region is considered.

National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Fluid Mechanics and Acoustics
Research subject
Machine Elements; Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-14194 (URN)10.1243/13506501JET697 (DOI)000281483600007 ()2-s2.0-77955635133 (Scopus ID)d8b8ebe0-b989-11df-a707-000ea68e967b (Local ID)d8b8ebe0-b989-11df-a707-000ea68e967b (Archive number)d8b8ebe0-b989-11df-a707-000ea68e967b (OAI)
Note
Validerad; 2010; 20100906 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Cupillard, S., Glavatskih, S. & Cervantes, M. (2009). 3D thermohydrodynamic analysis of a textured slider (ed.). Paper presented at . Tribology International, 42(10), 1487-1495
Open this publication in new window or tab >>3D thermohydrodynamic analysis of a textured slider
2009 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 42, no 10, p. 1487-1495Article in journal (Refereed) Published
Abstract [en]

Analysis of a 3D inlet textured slider bearing with a temperature dependent fluid is performed. Numerical simulations are carried out for a laminar and steady flow. Hot and cold lubricant mixing in the groove is modelled and examined for different operating conditions. Thermohydrodynamic performance of the bearing is analysed for different texture lengths. Results show that texture has a stronger and positive influence on load carrying capacity when thermal effects are considered. This beneficial effect is at a maximum for the longest dimples with a length shorter than the pad length. Texture is also beneficial for the load carrying capacity when the sliding speed and inlet flow rate are varied. The load carrying capacity of the slider can be increased by up to 16% in severe operating conditions (high sliding speed).

National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Fluid Mechanics and Acoustics
Research subject
Machine Elements; Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-12301 (URN)10.1016/j.triboint.2009.05.021 (DOI)000270126500012 ()2-s2.0-68349155815 (Scopus ID)b695c9d0-4e9f-11de-afea-000ea68e967b (Local ID)b695c9d0-4e9f-11de-afea-000ea68e967b (Archive number)b695c9d0-4e9f-11de-afea-000ea68e967b (OAI)
Note
Validerad; 2009; 20090601 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Cupillard, S. (2009). Thermohydrodynamics of sliding contacts with textured surfaces (ed.). (Doctoral dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Thermohydrodynamics of sliding contacts with textured surfaces
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Hydrodynamic sliding contacts like those found in journal or thrust bearings are frequently encountered in various types of machinery from computers to large turbines. These contacts, involving a variation in film thickness, are used to generate pressure in the lubricant film and separate the surfaces in relative motion. The contacts must carry a load while maintaining friction as low as possible. Environmental and economic concerns require the machines to operate with minimal power consumption. A number of design modifications have been proposed over the years in order to improve performance of such hydrodynamic contacts. There are experimental indications that textured surfaces, composed of a pattern of well-defined identical shapes, can improve hydrodynamic performance. There is therefore a need to understand and explain the effects of textured surfaces on hydrodynamic contact performance. A Computational Fluid Dynamics (CFD) analysis of the flow field can provide such an understanding. The full Navier-Stokes equations are solved using CFD code for both a slider and a journal bearing. Thermal and cavitation effects are considered. Numerical techniques that deform the computational grid in time are used to recalculate the film gap and simulate the motion of a microgroove located on a moving surface.For a texture located in the inlet part of the stationary surface of an inclined slider, the pressure build-up mechanism is investigated. Such a texture decreases losses locally and allows for increased pressure and a higher load carrying capacity. A critical value of the texture depth separates positive and negative effects of inertia on the load carrying capacity of the slider. The texture studied here provides maximum efficiency when its depth is such that the lubricant flow occurs at the onset of recirculation. In 3D, the texture length should be close to the pad length to generate the highest load carrying capacity. Improvements in performance are shown for different operating conditions. One important effect is that the load carrying capacity of the slider can be increased by up to 16% under severe thermal operating conditions. A journal bearing textured with microgrooves on the stationary surface is investigated. The coefficient of friction can be reduced if grooves of suitable depth are introduced. Under light loading (eccentricity ratios less than 0.15), shallow microgrooves (with a depth less than the minimum film thickness) placed in the maximum film region increase the minimum film thickness while reducing the friction force. The load carrying capacity is enhanced based on the same principle as for the inlet textured slider. Under high loading (eccentricity ratios greater than 0.5), deep microgrooves (with a depth greater than the minimum film thickness) placed in the maximum pressure region reduce both friction force and minimum film thickness. Nevertheless, for high loading, the texture provides better reduction in friction force than a smooth bearing operating with a thinner lubricant.A microgroove positioned on the moving surface, i.e., on the shaft of a journal bearing is also studied. A 2D isothermal case is investigated to explain the effect of the microgroove on the pressure profile and the behaviour of the load carrying capacity over one shaft revolution. The microgroove decreases pressure locally at every circumferential position, resulting in a decrease in the averaged load carrying capacity. A 3D thermal case is analysed to show how lubricant transport is modified by a microgroove. The microgroove affects thermal mixing as it carries a greater amount of cold lubricant to regions with high temperatures. This effect, more pronounced with deeper microgrooves, is due to a global flow recirculation inside the microgroove, which improves mixing.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2009. p. 59
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
Keywords
Engineering mechanics - Fluid mechanics, Teknisk mekanik - Strömningsmekanik
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-26208 (URN)d2c9eff0-b362-11de-b4d6-000ea68e967b (Local ID)978-91-7439-009-4 (ISBN)d2c9eff0-b362-11de-b4d6-000ea68e967b (Archive number)d2c9eff0-b362-11de-b4d6-000ea68e967b (OAI)
Note

Godkänd; 2009; 20091007 (samcup); DISPUTATION Ämnesområde: Maskinelement/Machine Elements Opponent: Professor Paul Allaire, University of Virginia, USA Ordförande: Professor Sergei Glavatskih, Luleå tekniska universitet Tid: Torsdag den 12 november 2009, kl 10.00 Plats: E 231, Luleå tekniska universitet

Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-02-26Bibliographically approved
Cupillard, S., Glavatskih, S. & Cervantes, M. (2008). 3D thermodynamic analysis of a textured slider (ed.). In: (Ed.), Jaakko Kleemola; Arto Lehtovaara (Ed.), Proceedings of NORDTRIB 2008, 13th Nordic Symposium on Tribology: Scandic Rosendahl Hotel, Tampere, Finland, June 10 - 13, 2008. Paper presented at Nordic Symposium on Tribology : 10/06/2008 - 13/06/2008. Tampere: Tampere University of Technology
Open this publication in new window or tab >>3D thermodynamic analysis of a textured slider
2008 (English)In: Proceedings of NORDTRIB 2008, 13th Nordic Symposium on Tribology: Scandic Rosendahl Hotel, Tampere, Finland, June 10 - 13, 2008 / [ed] Jaakko Kleemola; Arto Lehtovaara, Tampere: Tampere University of Technology, 2008Conference paper, Published paper (Refereed)
Abstract [en]

Analysis of a 3D inlet textured slider bearing with a temperature dependent fluid is performed. Numerical simulations are carried out for a laminar and steady flow. Hot and cold lubricant mixing in the groove is modelled and examined for different operating conditions. Thermohydrodynamic performance of the bearing is analysed for different texture lengths. Results show that texture has a stronger and positive influence on load carrying capacity when thermal effects are considered. This beneficial effect is at a maximum for the longest dimples with a length shorter than the pad length. Texture is also beneficial for the load carrying capacity when the sliding speed and inlet flow rate are varied: with an appropriate supply mass flow, load carrying capacity can be increased by 6-7% at low sliding speeds.

Place, publisher, year, edition, pages
Tampere: Tampere University of Technology, 2008
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-34135 (URN)840aeec0-6834-11dd-9c8e-000ea68e967b (Local ID)978-952-15-1959-8 (ISBN)840aeec0-6834-11dd-9c8e-000ea68e967b (Archive number)840aeec0-6834-11dd-9c8e-000ea68e967b (OAI)
Conference
Nordic Symposium on Tribology : 10/06/2008 - 13/06/2008
Note
Godkänd; 2008; Bibliografisk uppgift: 1 CD-ROM; 20080812 (cervante)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-01-14Bibliographically approved
Cupillard, S., Cervantes, M. & Glavatskih, S. (2008). A CFD study of a finite textured journal bearing (ed.). In: (Ed.), Hydro technology and the evironment for the new century: 24th IAHR Symposium on Hydraulic Machinery and Systems, October 27 - 31, 2008, Foz do Iguassu, Brazil. Paper presented at IAHR Symposium on Hydraulic Machinery and Systems : 27/10/2008 - 31/10/2008. Foz do Iguassu
Open this publication in new window or tab >>A CFD study of a finite textured journal bearing
2008 (English)In: Hydro technology and the evironment for the new century: 24th IAHR Symposium on Hydraulic Machinery and Systems, October 27 - 31, 2008, Foz do Iguassu, Brazil, Foz do Iguassu, 2008Conference paper, Published paper (Refereed)
Abstract [en]

An analysis of a lubricated journal bearing is performed with special attention to the influence of textured surfaces which may improve hydrodynamic performance. The bearing is subjected to an external applied load and the force balance is fulfilled with the force of the flow acting on the bearing. The position of the shaft is fixed whereas the bearing, centred at the starting time, moves under the forces until equilibrium is reached. A mesh deformation technique is used with CFD (Computational Fluid Dynamics) in order to perform the simulations. The flow is laminar, isothermal, three-dimensional (3D) and unsteady. Cavitation is taken into account. Results are analysed with smooth and textured surfaces on the bearing. Friction force and eccentricity ratio are compared for different configurations.It is found that shallow grooves under light loading (ε < 0.15) enhance the minimum film thickness while reducing the friction force. Under high loading (ε > 0.5), deep grooves are able to reduce the friction force despite a reduced minimum film thickness. For the second case, the predicted performance is superior to those of a smooth journal bearing with thinner lubricant.

Place, publisher, year, edition, pages
Foz do Iguassu: , 2008
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-27393 (URN)0d536f40-b010-11dd-b677-000ea68e967b (Local ID)0d536f40-b010-11dd-b677-000ea68e967b (Archive number)0d536f40-b010-11dd-b677-000ea68e967b (OAI)
Conference
IAHR Symposium on Hydraulic Machinery and Systems : 27/10/2008 - 31/10/2008
Note

Godkänd; 2008; Bibliografisk uppgift: 1 CD-ROM; 20081111 (ysko)

Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-01-14Bibliographically approved

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