유막온도경계조건이 평행 슬라이더 베어링의 윤활성능에 미치는 영향
Effect of Film-Temperature Boundary Conditions on the Lubrication Performance of Parallel Slider Bearing
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In sliding bearings, viscous friction due to high shear acting on the bearing surface raises the oil temperature. One of the mechanisms responsible for generating the load-carrying capacity in parallel surfaces is known as the viscosity wedge effect. In this paper, we investigate the effect of film-temperature boundary conditions on the thermohydrodynamic (THD) lubrication of parallel slider bearings. For this purpose, the continuity equation, Navier-Stokes equation, and the energy equation with temperature-viscosity-density relations are numerically analyzed using the commercial computational fluid dynamics (CFD) code FLUENT. Two different film-temperature boundary conditions are adopted to investigate the pressure generation mechanism. The temperature and viscosity distributions in the film thickness and flow directions were obtained, and the factors related to the pressure generation in the equation of motion were examined in detail. It was confirmed that the temperature gradients in the film and flow directions contribute heavily to the thermal wedge effect, due to which parallel slider bearing can not only support a considerable load but also reduce the frictional force, and its effect is significantly changed with the film-temperature boundary conditions. The present results can be used as basic data for THD analysis of surface-textured sliding bearings; however, further studies on various film-temperature boundary conditions are required.
Abstract
In sliding bearings, viscous friction due to high shear acting on the bearing surface raises the oil temperature. One of the mechanisms responsible for generating the load-carrying capacity in parallel surfaces is known as the viscosity wedge effect. In this paper, we investigate the effect of film-temperature boundary conditions on the thermohydrodynamic (THD) lubrication of parallel slider bearings. For this purpose, the continuity equation, Navier-Stokes equation, and the energy equation with temperature-viscosity-density relations are numerically analyzed using the commercial computational fluid dynamics (CFD) code FLUENT. Two different film-temperature boundary conditions are adopted to investigate the pressure generation mechanism. The temperature and viscosity distributions in the film thickness and flow directions were obtained, and the factors related to the pressure generation in the equation of motion were examined in detail. It was confirmed that the temperature gradients in the film and flow directions contribute heavily to the thermal wedge effect, due to which parallel slider bearing can not only support a considerable load but also reduce the frictional force, and its effect is significantly changed with the film-temperature boundary conditions. The present results can be used as basic data for THD analysis of surface-textured sliding bearings; however, further studies on various film-temperature boundary conditions are required.
참고문헌 (18)
- Lebeck, A. O., "Parallel sliding load support in the mixed friction regime. Part 1-The experimental data", ASME J. Tribol, 109(1), pp.189~195 (1987)
- Cameron, A., "The viscosity wedge", ASLE Trans, 1(2), pp.248~253 (1958)
- Khonsari, M. M., "A review of thermal effects in hydrodynamic bearings. Part I : Slider and thrust bearings", ASLE Trans, 30(1), pp.19~25 (1987)
- Cui, J., "The Relation between thermal wedge and thermal boundary conditions for the load-carrying capacity of a rectangular pad and a slider with parallel gaps", ASME J. Tribol., 138(2), pp.024502-1~024502-6
- Etsion, I., "State of the art in laser surface texturing", ASME J. Tribol, 127(1), pp.248~253 (2005)
- Gropper, D., "Hydrodynamic lubrication of textured surfaces : A review of modeling techniques and key findings", Tribol. Int., 94, pp.509~529 (2016)
- 박태조, "Laser Texturing한 평행 스러스트 베어링의 윤활특성 : 제1보 - 딤플깊이의 영향", 한국윤활학회지, 25(5), pp.305~310 (2009), 한국윤활학회
- 박태조, "Laser Texturing한 평행 스러스트 베어링의 윤활특성 : 제2보 - 딤플 위치의 영향", 한국윤활학회지, 26(1), pp.1~6 (2010), 한국윤활학회
- 박태조, "Laser Texturing한 평행 스러스트 베어링의 윤활특성 : 제3보 - 딤플 수의 영향", 한국윤활학회지, 27(6), pp.302~307 (2011), 한국윤활학회
- 박태조, "Laser Texturing한 평행 스러스트 베어링의 윤활특성 : 제4보 - 딤플 형상의 영향", 한국윤활학회지, 27(6), pp.338~343 (2011), 한국윤활학회
- 박태조, "Micro-Texturing한 Slider Bearing의 윤활특성 : 딤플 밀도의 영향", 대한기계학회논문집 A, 37(4), pp.437~442 (2013), 대한기계학회
- Dobrica, M. B., "Thermohydrodynamic behavior of a slider pocket bearing", ASME J. Tribol, 128(2), pp.312~318 (2006)
- Cupillard, S., "3D Thermohydrodynamic analysis of a textured slider", Tribol. Int, 42(10), pp.1487~1495 (2009)
- 정요한, "Surface Texturing한 평행 스러스트 베어링의 열유체윤활 해석: 딤플 반경과 깊이의 영향", 한국윤활학회지, 30(5), pp.303~310 (2014), 한국윤활학회[DOI]
- Meng, X., "On the effect of viscosity wedge in micro-textured parallel surfaces", Tribol. Int., 107, pp.116~124
- "ANSYS FLUENT User Guide, Release 14.0", ANSYS, Inc., ~ (2011)
- Brajdic-Mitidieri, P., "CFD analysis of a low friction pocketed pad bearing", ASME J. Tribol, 127, pp.803~812 (2005)
- Olver, A. V., "‘Inlet Suction’, a load support mechanism in nonconvergent, pocketed, hydrodynamic bearings", Proc. IMechE., J. Eng. Tribol, 220(2), pp.105~108 (2006)