等边三角形微孔端面机械密封多楔现象对性能的影响
|
摘要
微孔端面机械密封是通过设计改变微孔的几何特性以期望得到更优的密封性能,但几何特性如何影响密封性能却缺乏机理上的研究和指导。结合流体楔效应理论,采用数值计算的方法,基于Fluent多相流空化模型,针对等边三角形微孔端面机械密封,建立了其中1个微孔周期的间隙流体的3维数值计算模型,研究不同方向角下等边三角形微孔几何特性的改变对泄漏率和开启力的影响。首先,使用了流动因子判定流动状态、网格无关性分析确定网格尺寸、文献计算结果对比等方法,保证了数值计算模型的正确性。然后,结合楔效应理论与压力云图分析,提出了多楔现象,即:等边三角形微孔存在3个性质不同的楔。方向角的变化改变了各楔与密封端面旋转线速度间的夹角,故各楔的性质与强度随方向角的变化而变化。流体流经各楔,会产生不同的楔效应,多楔效应的组合影响了压力分布,最终决定了密封性能。最后,基于多楔现象,研究了等边三角形微孔端面机械密封的泄漏率与开启力。低压差下,方向角α=40°时泄漏率最小;高压差下,α=110°时泄漏率最小;增大转速将强化泄漏率的变化趋势。开启力在α∈[0°,120°]时,先减小后增大,α=60°时开启力最小;当α∈[0°,40°]及α∈[100°,120°]时,开启力随转速增加而增大;当α∈[40°,100°]时,开启力随转速增加而减小。
The mechanism of how the geometric features of dimples work on the performance of mechanical seal with micro-dimple has been rarely studied, although the geometric design of dimples is one of the most important means for enhancing the performance. In order treat this problem, based on the multiphase flow cavitation model in fluent, the wedge effect theory and the numerical calculation were employed to develop a three-dimensional numerical model of the lubricant in mechanical seal with equilateral triangular dimples for studying the effect of the geometric features on the leakage rate and the load-carrying capacity at different orientation angles. Firstly, the fluid factor was calculated for the flow pattern check, and the grid independence test of film was conducted for determining the grid size. The simulation result was also compared with the reference in order to ensure the accuracy of calculation model. Secondly, the multi-wedge phenomenon was proposed based on the wedge effect theory and the analysis of pressure contours. The equilateral triangular dimple has three different wedges. The orientation angle changes the angles between each wedge and the rotational velocity of seal face, which determines the character and intensity of the wedges. The cooperation of the three wedge effects influences the pressure distribution, and then determines the sealing performance. Finally, the leakage rate and load-carrying capacity of the mechanical seal with equilateral triangular dimples were studied based on the multi-wedge phenomenon. The leakage rate is minimal when the orientation angle α=40° for the low pressure difference, and α=110° for the high pressure difference. The increase of velocity enhances the change trend of leakage rate. The load-carrying capacity decreases at first, and then increases when α∈[0°,120°], and is minimal when α=60°. With the increase of velocity, the load-carrying capacity increases when α∈[0°,40°] and α∈[100°,120°], but decreases whenα∈[40°,100°].
The mechanism of how the geometric features of dimples work on the performance of mechanical seal with micro-dimple has been rarely studied, although the geometric design of dimples is one of the most important means for enhancing the performance. In order treat this problem, based on the multiphase flow cavitation model in fluent, the wedge effect theory and the numerical calculation were employed to develop a three-dimensional numerical model of the lubricant in mechanical seal with equilateral triangular dimples for studying the effect of the geometric features on the leakage rate and the load-carrying capacity at different orientation angles. Firstly, the fluid factor was calculated for the flow pattern check, and the grid independence test of film was conducted for determining the grid size. The simulation result was also compared with the reference in order to ensure the accuracy of calculation model. Secondly, the multi-wedge phenomenon was proposed based on the wedge effect theory and the analysis of pressure contours. The equilateral triangular dimple has three different wedges. The orientation angle changes the angles between each wedge and the rotational velocity of seal face, which determines the character and intensity of the wedges. The cooperation of the three wedge effects influences the pressure distribution, and then determines the sealing performance. Finally, the leakage rate and load-carrying capacity of the mechanical seal with equilateral triangular dimples were studied based on the multi-wedge phenomenon. The leakage rate is minimal when the orientation angle α=40° for the low pressure difference, and α=110° for the high pressure difference. The increase of velocity enhances the change trend of leakage rate. The load-carrying capacity decreases at first, and then increases when α∈[0°,120°], and is minimal when α=60°. With the increase of velocity, the load-carrying capacity increases when α∈[0°,40°] and α∈[100°,120°], but decreases whenα∈[40°,100°].
引文
[1]Etsion I,Micheal O.Enhancing sealing and dynamic performance with partially porous mechanical face seals[J].Tribology Transactions,1994,37(4):701-710.
[2]Etsion I.State of the art in laser surface texturing[J].Journal of Tribology,2005,127(1):248-253.
[3]Siripuram R B,Stephens L S.Effect of deterministic asperity geometry on hydrodynamic lubrication[J].Journal of Tribology,2004,126(3):527-534.
[4]Peng Xudong,Du Dongbo,Sheng Songen,et al.Effect of face asperity geometry on performance of a liquid lubricated face seal[J].Tribology,2007,27(4):352-356.[彭旭东,杜东波,盛颂恩,等.端面微形体对液体润滑机械密封性能的影响[J].摩擦学学报,2007,27(4):352-356.]
[5]Bai Shaoxian,Peng Xudong,Li Yefeng,et al.A hydrodynamic laser surface-textured gas mechanical face seal[J].Tribology Letters,2010,38(2):187-194.
[6]Bai Shaoxian,Peng Xudong,Li Jiyun,et al.Experimental study on hydrodynamic effect of orientation micro-pored surfaces[J].Science China(Technological Sciences),2011,54(3):659-662.
[7]Meng Xiangkai,Bai Shaoxian,Peng Xudong.Lubricationfilm flow control by oriented dimples for liquid lubricated mechanical seals[J].Tribology International,2014,77:132-141.
[8]Uddin M S,Liu Y W.Design and optimization of a new geometric texture shape for the enhancement of hydrodynamic lubrication performance of parallel slider surfaces[J].Biosurface&Biotribology,2016,2(2):59-69.
[9]Hsu S M,Jing Y,Hua D,et al.Friction reduction using discrete surface textures:Principle and design[J].Journal of Physics D(Applied Physics),2014,47(33):335-307.
[10]Syed I,Sarangi M.Hydrodynamic lubrication with deterministic micro textures considering fluid inertia effect[J].Tribology International,2014,69:30-38.
[11]温诗铸,黄平.摩擦学原理[M].北京:清华大学出版社,2012:25-27.
[12]Lebeck A O.Principles and design of mechanical face seals[M].New York:John Wiley&Sons,Inc.,1991.
[13]Zhang Ke,Ji Hua,Li Yanlin,et al.Relationship between geometric convergent point and leakage rate of mechanical seal with elliptical dimples[J].Tribology,2017(5):602-609.[张科,吉华,李岩霖,等.椭圆微孔端面机械密封泄漏率与几何收敛点的关系[J].摩擦学学报,2017(5):602-609.]
[14]Yu Haiwu,Yuan Sihuan,Sun Zao,et al.Effect of microdimple shapes on tribological properties of specimen surfaces[J].Journal of South China University of Technology(Natural Science Edition),2011,39(1):106-110.[于海武,袁思欢,孙造,等.微凹坑形状对试件表面摩擦特性的影响[J].华南理工大学学报(自然科学版),2011,39(1):106-110.]
[15]Ibatan T,Uddin M S,Chowdhury M A K.Recent development on surface texturing in enhancing tribological performance of bearing sliders[J].Surface&Coatings Technology,2015,272:102-120.
[16]Chen Huilong,Wang Qiang,Li Wenyu,et al.Numerical simulation of 3-d flow in upstream pumping mechanical seals with spiral grooves based on Fluent[J].Lubrication Engineering,2012,37(2):16-19.[陈汇龙,王强,李雯瑜,等.基于Fluent的螺旋槽上游泵送机械密封三维微间隙流场数值模拟[J].润滑与密封,2012,37(2):16-19.]
[17]Chen Huilong,Zhai Xiao,Zhao Binjuan,et al.Comparison of numerical analysis on the mechanical seal with porous seal ring face by multi-grid and CFD methods[J].Lubrication Engineering,2009,34(10):36-40.[陈汇龙,翟晓,赵斌娟,等.基于多重网格法和CFD的多孔端面机械密封数值分析比较[J].润滑与密封,2009,34(10):36-40.]
[18]Huang Weifeng,Gao Zhi,Li Anwei,et al.Comparison between Reynolds equation and Navier-Stokes equation on spiral-grooved dry gas seals[J].Journal of Tsinghua University(Science and Technology),2010(11):1820-1824.[黄伟峰,高志,黎安伟,等.基于Reynolds方程和基于N-S方程的干气密封性能分析对比[J].清华大学学报(自然科学版),2010(11):1820-1824.]
[19]Chen Huilong,Wu Qiangbo,Chen Xu,et al.Research on cavitation regions of upstream pumping mechanical seal based on dynamic mesh technique[J].Advances in Mechanical Engineering,2014(11):1-8.
[20]Hao Muming,Zhuang Yuan,Zhang Dahai,et al.Numerical study on sealing performance of spiral groove liquid film seal considering effects of cavitation[J].Journal of China University of Petroleum(Natual Science Eidition),2015,39(3):132-137.[郝木明,庄媛,章大海,等.考虑空化效应的螺旋槽液膜密封特性数值研究[J].中国石油大学学报(自然科学版),2015,39(3):132-137.]
[21]Qiu Y,Khonsari M M.On the prediction of cavitation in dimples using a mass-conservative algorithm[J].Journal of Tribology,2009,131(4):1-11.
[2]Etsion I.State of the art in laser surface texturing[J].Journal of Tribology,2005,127(1):248-253.
[3]Siripuram R B,Stephens L S.Effect of deterministic asperity geometry on hydrodynamic lubrication[J].Journal of Tribology,2004,126(3):527-534.
[4]Peng Xudong,Du Dongbo,Sheng Songen,et al.Effect of face asperity geometry on performance of a liquid lubricated face seal[J].Tribology,2007,27(4):352-356.[彭旭东,杜东波,盛颂恩,等.端面微形体对液体润滑机械密封性能的影响[J].摩擦学学报,2007,27(4):352-356.]
[5]Bai Shaoxian,Peng Xudong,Li Yefeng,et al.A hydrodynamic laser surface-textured gas mechanical face seal[J].Tribology Letters,2010,38(2):187-194.
[6]Bai Shaoxian,Peng Xudong,Li Jiyun,et al.Experimental study on hydrodynamic effect of orientation micro-pored surfaces[J].Science China(Technological Sciences),2011,54(3):659-662.
[7]Meng Xiangkai,Bai Shaoxian,Peng Xudong.Lubricationfilm flow control by oriented dimples for liquid lubricated mechanical seals[J].Tribology International,2014,77:132-141.
[8]Uddin M S,Liu Y W.Design and optimization of a new geometric texture shape for the enhancement of hydrodynamic lubrication performance of parallel slider surfaces[J].Biosurface&Biotribology,2016,2(2):59-69.
[9]Hsu S M,Jing Y,Hua D,et al.Friction reduction using discrete surface textures:Principle and design[J].Journal of Physics D(Applied Physics),2014,47(33):335-307.
[10]Syed I,Sarangi M.Hydrodynamic lubrication with deterministic micro textures considering fluid inertia effect[J].Tribology International,2014,69:30-38.
[11]温诗铸,黄平.摩擦学原理[M].北京:清华大学出版社,2012:25-27.
[12]Lebeck A O.Principles and design of mechanical face seals[M].New York:John Wiley&Sons,Inc.,1991.
[13]Zhang Ke,Ji Hua,Li Yanlin,et al.Relationship between geometric convergent point and leakage rate of mechanical seal with elliptical dimples[J].Tribology,2017(5):602-609.[张科,吉华,李岩霖,等.椭圆微孔端面机械密封泄漏率与几何收敛点的关系[J].摩擦学学报,2017(5):602-609.]
[14]Yu Haiwu,Yuan Sihuan,Sun Zao,et al.Effect of microdimple shapes on tribological properties of specimen surfaces[J].Journal of South China University of Technology(Natural Science Edition),2011,39(1):106-110.[于海武,袁思欢,孙造,等.微凹坑形状对试件表面摩擦特性的影响[J].华南理工大学学报(自然科学版),2011,39(1):106-110.]
[15]Ibatan T,Uddin M S,Chowdhury M A K.Recent development on surface texturing in enhancing tribological performance of bearing sliders[J].Surface&Coatings Technology,2015,272:102-120.
[16]Chen Huilong,Wang Qiang,Li Wenyu,et al.Numerical simulation of 3-d flow in upstream pumping mechanical seals with spiral grooves based on Fluent[J].Lubrication Engineering,2012,37(2):16-19.[陈汇龙,王强,李雯瑜,等.基于Fluent的螺旋槽上游泵送机械密封三维微间隙流场数值模拟[J].润滑与密封,2012,37(2):16-19.]
[17]Chen Huilong,Zhai Xiao,Zhao Binjuan,et al.Comparison of numerical analysis on the mechanical seal with porous seal ring face by multi-grid and CFD methods[J].Lubrication Engineering,2009,34(10):36-40.[陈汇龙,翟晓,赵斌娟,等.基于多重网格法和CFD的多孔端面机械密封数值分析比较[J].润滑与密封,2009,34(10):36-40.]
[18]Huang Weifeng,Gao Zhi,Li Anwei,et al.Comparison between Reynolds equation and Navier-Stokes equation on spiral-grooved dry gas seals[J].Journal of Tsinghua University(Science and Technology),2010(11):1820-1824.[黄伟峰,高志,黎安伟,等.基于Reynolds方程和基于N-S方程的干气密封性能分析对比[J].清华大学学报(自然科学版),2010(11):1820-1824.]
[19]Chen Huilong,Wu Qiangbo,Chen Xu,et al.Research on cavitation regions of upstream pumping mechanical seal based on dynamic mesh technique[J].Advances in Mechanical Engineering,2014(11):1-8.
[20]Hao Muming,Zhuang Yuan,Zhang Dahai,et al.Numerical study on sealing performance of spiral groove liquid film seal considering effects of cavitation[J].Journal of China University of Petroleum(Natual Science Eidition),2015,39(3):132-137.[郝木明,庄媛,章大海,等.考虑空化效应的螺旋槽液膜密封特性数值研究[J].中国石油大学学报(自然科学版),2015,39(3):132-137.]
[21]Qiu Y,Khonsari M M.On the prediction of cavitation in dimples using a mass-conservative algorithm[J].Journal of Tribology,2009,131(4):1-11.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |