The research on surface texture is developing from single macro-texture to composite micro-nano texture.The current research on the anti-friction mechanism and theoretical models of textures is relatively weak.Studyin...The research on surface texture is developing from single macro-texture to composite micro-nano texture.The current research on the anti-friction mechanism and theoretical models of textures is relatively weak.Studying the characteristics of different types of surface textures and determining the applicable working conditions of each texture is the focus of current research.In this paper,a mathematical model of hydrodynamic lubrication is established based on Navier-Stokes equations.The FLUENT software is used to simulate and analyze the four texture models,explore the dynamic pressure lubrication characteristics of different texture types,and provide data support for texture optimization.The key variable values required by the mathematical model are obtained through the simulation data.The friction coefficient of the texture under different working conditions was measured through friction and wear experiments,and the mathematical model was verified by the experimental results.The research results show that circular texture is suitable for low to medium speed and high load conditions,chevron texture is suitable for medium to high speed and medium to high load conditions,groove texture is suitable for high speed and low load conditions,and composite texture is suitable for high speed and medium to high load conditions.Comparing the experimental results with the results obtained by the mathematical model,it is found that the two are basically the same in the ranking of the anti-friction performance of different textures,and there is an error of 10%−40%in the friction coefficient value.In this study,a mathematical model of hydrodynamic lubrication was proposed,and the solution method of the optimal surface texture model was determined.展开更多
We study the periodic boundary value problems for nonlinear integro-differential equa-tions of Volterra type with Carathéodory functions. For two situations relative to lower and uppersolutions α and β:αβ or...We study the periodic boundary value problems for nonlinear integro-differential equa-tions of Volterra type with Carathéodory functions. For two situations relative to lower and uppersolutions α and β:αβ or βα, the existence of solutions and the monotone iterative method forestablishing extreme solutions are considered.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.51575234,51872122)Postdoctoral Science Foundation of China(Grant No.2017M620286)+3 种基金Key Research and Development Program of Shandong,Province,China(Grant No.2018CXGC0809)Major basic research projects of Shandong Natural Science Foundation(Grant No.ZR2020ZD06)Project of Shandong Province Higher,Educational Youth Innovation Science and Technology,Program(Grant No.2019KJB021)Experts from Taishan Scholars,and Youth Innovation in Science&Technology Support Plan of Shandong Province University.
文摘The research on surface texture is developing from single macro-texture to composite micro-nano texture.The current research on the anti-friction mechanism and theoretical models of textures is relatively weak.Studying the characteristics of different types of surface textures and determining the applicable working conditions of each texture is the focus of current research.In this paper,a mathematical model of hydrodynamic lubrication is established based on Navier-Stokes equations.The FLUENT software is used to simulate and analyze the four texture models,explore the dynamic pressure lubrication characteristics of different texture types,and provide data support for texture optimization.The key variable values required by the mathematical model are obtained through the simulation data.The friction coefficient of the texture under different working conditions was measured through friction and wear experiments,and the mathematical model was verified by the experimental results.The research results show that circular texture is suitable for low to medium speed and high load conditions,chevron texture is suitable for medium to high speed and medium to high load conditions,groove texture is suitable for high speed and low load conditions,and composite texture is suitable for high speed and medium to high load conditions.Comparing the experimental results with the results obtained by the mathematical model,it is found that the two are basically the same in the ranking of the anti-friction performance of different textures,and there is an error of 10%−40%in the friction coefficient value.In this study,a mathematical model of hydrodynamic lubrication was proposed,and the solution method of the optimal surface texture model was determined.
基金Project supported by the National Natural Science Foundation of China
文摘We study the periodic boundary value problems for nonlinear integro-differential equa-tions of Volterra type with Carathéodory functions. For two situations relative to lower and uppersolutions α and β:αβ or βα, the existence of solutions and the monotone iterative method forestablishing extreme solutions are considered.
