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王勇,阮奇
《中国工程科学》 2006年 第8卷 第6期 页码 83-88
管内湍动流体摩擦因数是雷诺数和相对粗糙度的二元非线性函数,由Colebrook隐式方程计算摩擦因数要用迭代的方法求解,很不方便。为了得到形式简单、精度高的计算摩擦因数的显式方程,提出了二元非线性多项式智能拟合法。该法将二元非线性多项式转化成多元线性多项式并建立线性最小二乘法标准矩阵,用遗传算法结合矩阵法对多项式的项数、项型式项指数及项系数进行搜索得到最优的拟合函数式。用该法拟合了Colebrook方程解的数据,得到一个计算管内湍动流体摩擦因数的显式新方程。在雷诺数3.000≤Re≤108、相对粗糙度0≤e/d≤0.05的范围内,该方程计算结果与Colebrook方程的平均偏差为0.5%,最大偏差不超过1.8%,与实验数据偏差为2.3%。新方程具有形式简单、精度高、适用范围广的优点,且便于简化成光滑管或阻力平方区等情况下的计算摩擦因数的方程。
许立忠,黄真
《中国工程科学》 2002年 第4卷 第3期 页码 63-67
文章通过相对运动关系分析,给出了超环面行星蜗杆传动中共轭运动零件行星轮与定子、行星轮与蜗杆之间相对滑动率的计算方法,得出了凸峰接触时行星轮与定子及蜗杆之间摩擦系数的计算公式;以弹流润滑理论为基础,给出了液体润滑时行星轮与定子及蜗杆之间齿面摩擦系数的计算公式;进而给出了混合摩擦状态下行星轮与定子及蜗杆之间摩擦系数的计算公式。然后,运用上述公式讨论了液体润滑时行星轮与定子及蜗杆之间齿面摩擦系数的相对大小及其随传动参数的变化规律;给出了行星轮与定子全部为凸峰接触时摩擦系数随传动参数的变化规律;讨论了混合摩擦状态下,行星轮与定子之间摩擦系数随膜厚比的变化规律。
Comparative study of oscillating flow characteristics of cryocooler regenerator at low temperatures
Yonglin JU , Qingqing SHEN ,
《能源前沿(英文)》 2009年 第3卷 第1期 页码 80-84 doi: 10.1007/s11708-009-0008-y
关键词: friction factor regenerator oscillating flow high frequency
Analysis of nonlinear channel friction inverse problem
CHENG Weiping, LIU Guohua
《结构与土木工程前沿(英文)》 2007年 第1卷 第2期 页码 205-210 doi: 10.1007/s11709-007-0024-0
Effects of leakage and friction on the miniaturization of a Wankel compressor
Yilin ZHANG, Wen WANG
《能源前沿(英文)》 2011年 第5卷 第1期 页码 83-92 doi: 10.1007/s11708-010-0125-7
A multi-probe micro-fabrication apparatus based on the friction-induced fabrication method
Zhijiang WU, Chenfei SONG, Jian GUO, Bingjun YU, Linmao QIAN
《机械工程前沿(英文)》 2013年 第8卷 第4期 页码 333-339 doi: 10.1007/s11465-013-0276-4
A novel multi-probe micro-fabrication apparatus was developed based on the friction-induced fabrication method. The main parts of the apparatus include actuating device, loading system, and control system. With a motorized linear stage, the maximum fabrication area of 50 mm × 50 mm can be achieved, and the maximum sliding speed of probes can be as high as 10 mm/s. Through locating steel micro balls into indents array, the preparation of multi-probe array can be realized by a simple and low-cost way. The cantilever was designed as a structure of deformable parallelogram with two beams, by which the fabrication force can be precisely controlled. Combining the friction-induced scanning with selective etching in KOH solution, various micro-patterns were fabricated on Si(100) surface without any masks or exposure. As a low-cost and high efficiency fabrication device, the multi-probe micro-fabrication apparatus may encourage the development of friction-induced fabrication method and shed new light on the texture engineering.
关键词: friction-induced fabrication silicon surface texture friction multi-probe
M. ARULPRAKASAJOTHI,K. ELANGOVAN,K. HEMA CHANDRA REDDY,S. SURESH
《能源前沿(英文)》 2016年 第10卷 第2期 页码 136-142 doi: 10.1007/s11708-015-0389-z
王渭源
《中国工程科学》 2001年 第3卷 第8期 页码 29-32
当前,工程师和科学家都对微牛和纳牛量级载荷静摩擦系数(以下简称微牛纳牛静摩擦系数)很感兴趣。但文献中至今没有详细讨论过微牛纳牛静摩擦系数与载荷的关系,而且发表的实验结果都不相互讨论。从微分静摩擦系数的定义出发,导出几种典型模型下微分静摩擦系数和表观静摩擦系数的表式,并据此广泛讨论这些文献中的实验结果。
Air-side heat transfer and friction characteristics of biofouled evaporator under wet conditions
Hui PU, Guoliang DING, Xiaokui MA, Haitao HU, Yifeng GAO,
《能源前沿(英文)》 2010年 第4卷 第3期 页码 306-312 doi: 10.1007/s11708-009-0067-0
Modeling of the minimum cutting thickness in micro cutting with consideration of the friction around
Tianfeng ZHOU, Ying WANG, Benshuai RUAN, Zhiqiang LIANG, Xibin WANG
《机械工程前沿(英文)》 2020年 第15卷 第1期 页码 81-88 doi: 10.1007/s11465-019-0561-y
关键词: tool friction minimum cutting thickness finite element method tool edge radius micro cutting
Study of base friction simulation tests based on a complicated engineered bridge slope
Liu HE, Guang WU, Hua WANG
《结构与土木工程前沿(英文)》 2012年 第6卷 第4期 页码 393-397 doi: 10.1007/s11709-012-0174-6
关键词: base friction test slope stability evaluation bridge slope
Parametric study on the Multangular-Pyramid Concave Friction System (MPCFS) for seismic isolation
Wei XIONG, Shan-Jun ZHANG, Li-Zhong JIANG, Yao-Zhuang LI
《结构与土木工程前沿(英文)》 2020年 第14卷 第5期 页码 1152-1165 doi: 10.1007/s11709-020-0659-7
关键词: seismic isolation variable frequency near-fault earthquake numerical study Multangular-Pyramid Concave Friction System
Laboratory and field evaluation of asphalt pavement surface friction resistance
Zhong WU, Chris ABADIE
《结构与土木工程前沿(英文)》 2018年 第12卷 第3期 页码 372-381 doi: 10.1007/s11709-017-0463-1
Pavement surface friction is a significant factor for driving safety and plays a critical role in reducing wet-pavement crashes. However, the current asphalt mixture design procedure does not directly consider friction as a requirement. The objective of this study was to develop a surface friction prediction model that can be used during a wearing course mixture design. To achieve the objective, an experimental study was conducted on the frictional characteristics of typical wearing course mixtures in Louisiana. Twelve wearing course mixtures including dense-graded and open-graded mixes with different combinations of aggregate sources were evaluated in laboratory using an accelerated polishing and testing procedure considering both micro- and macro texture properties. In addition, the surface frictional properties of asphalt mixtures were measured on twenty-two selected asphalt pavement sections using different in situ devices including Dynamic Friction Tester (DFT), Circular Texture Meter (CTM), and Lock-Wheel Skid Trailer (LWST). The results have led to develop a procedure for predicting pavement end-of-life skid resistance based on the aggregate blend polish stone value, gradation parameters, and traffic, which is suited in checking whether the selected aggregates in a wearing course mix design would meet field friction requirements under a certain design traffic polishing.
关键词: friction skid resistance polishing PSV LWST micro-texture macro-texture
Subhash ANURAG, Yuebin GUO,
《机械工程前沿(英文)》 2010年 第5卷 第3期 页码 247-255 doi: 10.1007/s11465-010-0097-7
关键词: surface temperature friction residual stress finite element analysis (FEA) dry cutting tool property
Effect of friction coefficients on the dynamic response of gear systems
Lingli JIANG, Zhenyong DENG, Fengshou GU, Andrew D. BALL, Xuejun LI
《机械工程前沿(英文)》 2017年 第12卷 第3期 页码 397-405 doi: 10.1007/s11465-017-0415-4
The inevitable deterioration of the lubrication conditions in a gearbox in service can change the tribological properties of the meshing teeth. In turn, such changes can significantly affect the dynamic responses and running status of gear systems. This paper investigates such an effect by utilizing virtual prototype technology to model and simulate the dynamics of a wind turbine gearbox system. The change in the lubrication conditions is modeled by the changes in the friction coefficients, thereby indicating that poor lubrication causes not only increased frictional losses but also significant changes in the dynamic responses. These results are further demonstrated by the mean and root mean square values calculated by the simulated responses under different friction coefficients. In addition, the spectrum exhibits significant changes in the first, second, and third harmonics of the meshing components. The findings and simulation method of this study provide theoretical bases for the development of accurate diagnostic techniques.
关键词: dynamic response friction coefficient wind loads wind turbine gearbox
标题 作者 时间 类型 操作
Comparative study of oscillating flow characteristics of cryocooler regenerator at low temperatures
Yonglin JU , Qingqing SHEN ,
期刊论文
Effects of leakage and friction on the miniaturization of a Wankel compressor
Yilin ZHANG, Wen WANG
期刊论文
A multi-probe micro-fabrication apparatus based on the friction-induced fabrication method
Zhijiang WU, Chenfei SONG, Jian GUO, Bingjun YU, Linmao QIAN
期刊论文
Experimental investigation on heat transfer effect of conical strip inserts in a circular tube under laminar flow
M. ARULPRAKASAJOTHI,K. ELANGOVAN,K. HEMA CHANDRA REDDY,S. SURESH
期刊论文
Air-side heat transfer and friction characteristics of biofouled evaporator under wet conditions
Hui PU, Guoliang DING, Xiaokui MA, Haitao HU, Yifeng GAO,
期刊论文
Modeling of the minimum cutting thickness in micro cutting with consideration of the friction around
Tianfeng ZHOU, Ying WANG, Benshuai RUAN, Zhiqiang LIANG, Xibin WANG
期刊论文
Study of base friction simulation tests based on a complicated engineered bridge slope
Liu HE, Guang WU, Hua WANG
期刊论文
Parametric study on the Multangular-Pyramid Concave Friction System (MPCFS) for seismic isolation
Wei XIONG, Shan-Jun ZHANG, Li-Zhong JIANG, Yao-Zhuang LI
期刊论文
Laboratory and field evaluation of asphalt pavement surface friction resistance
Zhong WU, Chris ABADIE
期刊论文
Predictive model to decouple the contributions of friction and plastic deformation to machined surface
Subhash ANURAG, Yuebin GUO,
期刊论文