E-Thesis 44 views 13 downloads
A particle-based fluid modelling and its application to lubricating grease / KAZUYA YAMAMOTO
Swansea University Author: KAZUYA YAMAMOTO
DOI (Published version): 10.23889/SUThesis.67951
Abstract
Lubricating grease is used in a wide range of applications, such as gearboxes and ball bearings due to its unique advantages over oil, such as low maintenance and leak resistance. This study is sponsoredby NSK, the author's employer and a leading bearing manufacturer in Japan. In their product...
| Published: |
Swansea University, Wales, UK
2024
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Li, C. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa67951 |
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| Abstract: |
Lubricating grease is used in a wide range of applications, such as gearboxes and ball bearings due to its unique advantages over oil, such as low maintenance and leak resistance. This study is sponsoredby NSK, the author's employer and a leading bearing manufacturer in Japan. In their product development process of the most important product, ball bearings, a significant amount of trial and error is required in the experiment. Fast and accurate grease simulation could alleviate the situation, but in the relevant academic field, there have only been a limited number of works on grease simulation. More-over, those works hardly discuss the difference between greases with different material properties most likely because of the limited re-producibility of grease in simulation while there have been numerous experiment-based studies about the complex material properties of grease and the ball bearing performance. The simulation process is also reported to be time-consuming Setting the ultimate goal as the utilisation of the simulation in the speedy product development of grease-lubricated ball bearings, this study expands upon the material properties of grease by adding elastoplasticity to previously used strain-rate dependent viscosity, and examines the effectiveness of the widely used cone penetration test and a newly designed plate separation test, approximately representing the responses to compression and tension respectively. The model was found to improve the result in the cone penetration test, but some discrepancy was found in the plate separation test. This study was performed with an improved smoothed particle hydrodynamics called the reproducing kernel particle method, which was implemented from scratch. Considering the need for efficiency in product development, GPU parallel computing was deployed to accelerate simulation. While there was a significant speed-up compared to a serial CPU equivalent, the overall performance was limited by the time step constraint, an issue that exists regardless of whether a CPU or GPU is used. |
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| Item Description: |
A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information. |
| Keywords: |
Grease, ball bearings, cone penetration, lubrication, CFD, particle methods |
| College: |
Faculty of Science and Engineering |
| Funders: |
NSK LTD |