Evaluation of Various Shear-Thinning Models for Squalane Using Traction Measurements, TEHD and NEMD Simulations
The accurate prediction of friction in highly loaded concentrated contacts is one of the most challenging aspects of thermal elastohydrodynamic (TEHD) simulation. The correct modelling of fluid behaviour on the macroscale, in particular non-Newtonian flow behaviour, is an essential prerequisite. For...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-04-01
|
| Series: | Lubricants |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-4442/11/4/178 |
| _version_ | 1797604585707143168 |
|---|---|
| author | Thomas Neupert Dirk Bartel |
| author_facet | Thomas Neupert Dirk Bartel |
| author_sort | Thomas Neupert |
| collection | DOAJ |
| description | The accurate prediction of friction in highly loaded concentrated contacts is one of the most challenging aspects of thermal elastohydrodynamic (TEHD) simulation. The correct modelling of fluid behaviour on the macroscale, in particular non-Newtonian flow behaviour, is an essential prerequisite. For many years, shear-thinning models have been developed and validated with different approaches and controversially discussed. In basic research, model fluids are often used in this context, which have a similar behaviour to practical lubricants. Accompanied by earlier research results, this paper carries out comprehensive investigations on the rheometric behaviour of the model fluid squalane. Based on traction measurements at four different tribometers, an overall parameter optimisation and performance evaluation of three different shear-thinning models is performed using numerical TEHD simulations. In order to additionally validate the theoretical viscosity behaviour, the optimised shear-thinning curves are then compared with comprehensive non-equilibrium molecular dynamics (NEMD) simulations. The key aspect of this paper is the simultaneous consideration of the shear-thinning models in terms of rheometric, experimental, and simulative investigations without changing the parameters. All investigations show that the Eyring model, despite its simplicity, provides the best agreement in both the numerical contact simulation and the NEMD simulations. |
| first_indexed | 2024-03-11T04:48:21Z |
| format | Article |
| id | doaj.art-26ccf051f3ae482ebf9df11ff57a2c6d |
| institution | Directory Open Access Journal |
| issn | 2075-4442 |
| language | English |
| last_indexed | 2024-03-11T04:48:21Z |
| publishDate | 2023-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Lubricants |
| spelling | doaj.art-26ccf051f3ae482ebf9df11ff57a2c6d2023-11-17T20:08:08ZengMDPI AGLubricants2075-44422023-04-0111417810.3390/lubricants11040178Evaluation of Various Shear-Thinning Models for Squalane Using Traction Measurements, TEHD and NEMD SimulationsThomas Neupert0Dirk Bartel1Tribo Technologies GmbH, 39106 Magdeburg, GermanyFaculty of Mechanical Engineering, Otto von Guericke University Magdeburg, Chair of Machine Elements and Tribology, 39106 Magdeburg, GermanyThe accurate prediction of friction in highly loaded concentrated contacts is one of the most challenging aspects of thermal elastohydrodynamic (TEHD) simulation. The correct modelling of fluid behaviour on the macroscale, in particular non-Newtonian flow behaviour, is an essential prerequisite. For many years, shear-thinning models have been developed and validated with different approaches and controversially discussed. In basic research, model fluids are often used in this context, which have a similar behaviour to practical lubricants. Accompanied by earlier research results, this paper carries out comprehensive investigations on the rheometric behaviour of the model fluid squalane. Based on traction measurements at four different tribometers, an overall parameter optimisation and performance evaluation of three different shear-thinning models is performed using numerical TEHD simulations. In order to additionally validate the theoretical viscosity behaviour, the optimised shear-thinning curves are then compared with comprehensive non-equilibrium molecular dynamics (NEMD) simulations. The key aspect of this paper is the simultaneous consideration of the shear-thinning models in terms of rheometric, experimental, and simulative investigations without changing the parameters. All investigations show that the Eyring model, despite its simplicity, provides the best agreement in both the numerical contact simulation and the NEMD simulations.https://www.mdpi.com/2075-4442/11/4/178shear-thinningsqualanetraction measurementsTEHD simulationNEMD simulationfluid mechanics |
| spellingShingle | Thomas Neupert Dirk Bartel Evaluation of Various Shear-Thinning Models for Squalane Using Traction Measurements, TEHD and NEMD Simulations Lubricants shear-thinning squalane traction measurements TEHD simulation NEMD simulation fluid mechanics |
| title | Evaluation of Various Shear-Thinning Models for Squalane Using Traction Measurements, TEHD and NEMD Simulations |
| title_full | Evaluation of Various Shear-Thinning Models for Squalane Using Traction Measurements, TEHD and NEMD Simulations |
| title_fullStr | Evaluation of Various Shear-Thinning Models for Squalane Using Traction Measurements, TEHD and NEMD Simulations |
| title_full_unstemmed | Evaluation of Various Shear-Thinning Models for Squalane Using Traction Measurements, TEHD and NEMD Simulations |
| title_short | Evaluation of Various Shear-Thinning Models for Squalane Using Traction Measurements, TEHD and NEMD Simulations |
| title_sort | evaluation of various shear thinning models for squalane using traction measurements tehd and nemd simulations |
| topic | shear-thinning squalane traction measurements TEHD simulation NEMD simulation fluid mechanics |
| url | https://www.mdpi.com/2075-4442/11/4/178 |
| work_keys_str_mv | AT thomasneupert evaluationofvariousshearthinningmodelsforsqualaneusingtractionmeasurementstehdandnemdsimulations AT dirkbartel evaluationofvariousshearthinningmodelsforsqualaneusingtractionmeasurementstehdandnemdsimulations |