资源类型

期刊论文 884

年份

2024 1

2023 54

2022 66

2021 60

2020 65

2019 53

2018 43

2017 40

2016 38

2015 37

2014 26

2013 31

2012 38

2011 39

2010 45

2009 38

2008 56

2007 58

2006 18

2005 19

展开 ︾

关键词

动力特性 5

动力学 4

临床特征 3

动力响应 3

动态规划 3

2035 2

个人热管理 2

中国 2

中国特色 2

力学性能 2

动力气垫 2

动态管理 2

扬矿管 2

有限元 2

模态 2

海上风电场 2

深海采矿 2

燃烧性能 2

航天器 2

展开 ︾

检索范围：

排序： 展示方式：

Transfer function solving, simulating and testing of thermal dynamics characteristics of a ballscrew

Junyong XIA, Bo WU, Youmin HU, Tielin SHI,

《机械工程前沿（英文）》 2010年 第5卷 第2期   页码 233-241 doi: 10.1007/s11465-010-0014-0

摘要： Based on the theory of heat transfer, the transfer function between the thermal deformation of any point on the lead screw and the temperature of heat sources of a ballscrew under the influence of multi-changeable heat sources is solved by using the Laplace transform method. By solving the amplitude-frequency characteristics and phase-frequency characteristics of the transfer function, the steady-state response of thermal deformation of the ballscrew is obtained, and the thermal dynamics characteristics of the lead screw under the influence of multi-heat sources are further studied. Comparing with the result of finite-element simulation, the theoretical analyzing result accords with the steady-state part of the finite-element simulating result. Through tests of the steady-state response of thermal deformation, the thermal dynamics characteristics are further studied. The curves of tests by and large accord with the theoretical analyzing result, which shows that the method of transfer function is correct and valid in solving the steady-state response of thermal deformation.

关键词： ballscrew     Laplace transform     transfer function     thermal dynamic characteristics    

HTML PDF 收藏

Numerical solution, simulation and testing of the thermal dynamic characteristics of ball-screws

XIA Junyong, HU Youmin, WU Bo, SHI Tielin

《机械工程前沿（英文）》 2008年 第3卷 第1期   页码 28-36 doi: 10.1007/s11465-008-0007-4

摘要： This research focuses on the characteristics of how a ball-screw changes its temperature corresponding to the periodic change of the end-most heat source. Based on the theory of heat transfer, this paper supplies a numerical solution to the non-homogeneous equation of heat transfer through the group explicit (GE) finite difference approach. The temperature distribution for the ball-screw at different times and directions is shown. By simulating and modeling the temperature field and thermal deformation of the ball-screw under periodically varying heat sources, this paper describes the thermal dynamic characteristics of the ball-screw under such conditions. By testing the thermal dynamic characteristics of the ball-screw, the numerical solution is validated.

关键词： numerical solution     temperature corresponding     temperature distribution     end-most     ball-screw    

HTML PDF 收藏

Numerical study of thermal characteristics of double skin facade system with middle shade

Shaoning LIU, Xiangfei KONG, Hua YANG, Minchao FAN, Xin ZHAN

《能源前沿（英文）》 2021年 第15卷 第1期   页码 222-234 doi: 10.1007/s11708-017-0480-8

摘要： Architectural shade is an effective method for improving building energy efficiency. A new shade combined with the double skin façade (DSF) system, called middle shade (MS), was introduced and developed for buildings. In this paper, a 3D dynamic simulation was conducted to analyze the influence of MS combined with DSF on the indoor thermal characteristics. The research on MS for DSF involves the temperature, the ventilation rate, the velocity distribution of the air flow duct, and the indoor temperature. The results show that the angle and position of the shade in the three seasons are different, and different conditions effectively enhance the indoor thermal characteristics. In summer, the appearance of MS in DSF makes the indoor temperature significantly lower. The indoor temperature is obviously lower than that of the air flow duct, and the temperature of the air flow duct is less affected by MS. The influence of the position of blinds on indoor temperature and ventilation rate is greater than the influence of the angle of blinds. According to the climate characteristics of winter and transition season, in winter, early spring, and late autumn, the indoor temperature decreases with the increase of the position of blinds at daytime, but the opposite is true at night. The results found in this paper can provide reference for the design and use of MS combined with DSF in hot summer and cold winter zone.

关键词： middle shade     position     thermal characteristics     double skin facade    

HTML PDF 收藏

Dynamic characteristics of molten droplets and hot particles falling in liquid pool

Liangxing LI, Weimin MA, Huixiong LI, Tingkuan CHEN,

《能源前沿（英文）》 2010年 第4卷 第2期   页码 246-251 doi: 10.1007/s11708-009-0077-y

摘要： The dynamic characteristics of molten droplets and hot particles at the very beginning of their fall into coolant pools are presented. The falling course of a single droplet or a single hot particle was recorded by a high-speed camera and a curve of velocity . time was obtained. Emphasis was placed on the effects of the droplet’s size and temperature, the coolant’s temperature and properties, and the droplet’s physical properties on the moving behavior. The results for the all cases showed that the velocity of a falling droplet/particle decreased rapidly but rebounded shortly, at the beginning of droplet/particle falling in the coolant. Following such a V-shaped evolution in velocity, the droplet/particle slows down gradually to a comparatively steady velocity. An increase in either coolant temperature or droplet temperature results in a larger velocity variation in the “J-region”, but a smaller deceleration when it moves out of the “J-region”. The elevated volatility of a coolant leads to a steeper deceleration in the “J-region” and beyond. The bigger size of a particle leads to a greater velocity variation in the “J-region” and terminal velocity. A high melting point and thermal conductivity as well as lower heat capacity contribute to dramatic variation in the “J-region” and low terminal velocity.

关键词： dynamic characteristics     molten droplets     high-temperature particles     fuel and coolant interactions    

HTML PDF 收藏

Air-bearing position optimization based on dynamic characteristics of ultra-precision linear stages

CHEN Xuedong, LI Zhixin

《机械工程前沿（英文）》 2008年 第3卷 第4期   页码 400-407 doi: 10.1007/s11465-008-0060-z

摘要： Air-bearings are installed between the stator and the mover of ultra-precision linear stages to suppress vibration and mechanical contact. Spring-damping elements are used to emulate the complex interaction of the finite element model (FEM) developed in this paper and the system dynamic behaviors are analyzed. Through the experimental modal test, the validity and reliability of the model are proven. However, the dynamic characteristics including mode frequency, mode shape, and response amplitude are obviously changed with the position of air-bearings. The combined optimization method is used to optimize the air-bearings position. The best and worst positions are obtained using the dynamic characteristic analysis. The method can be generalized to the connection position of different components in manufacture elements and to implement the system dynamic characteristics optimization when the connection position can be changed.

关键词： manufacture     different     interaction     air-bearings     response amplitude    

HTML PDF 收藏

Dynamic characteristics of NC table with SVD

WANG Linhong, WU Bo, DU Runsheng, YANG Shuzi

《机械工程前沿（英文）》 2008年 第3卷 第4期   页码 385-391 doi: 10.1007/s11465-008-0052-z

摘要： This paper employs the SVD (singular value decomposition) method to study dynamic characteristics of a numerical control (NC) table. Acceleration signals of the NC table at three directions are tested; the singular spectrum of the signals is acquired with SVD; principal components of the signals are found out; dynamic characteristics of the signals and their contributing factors are studied by extracting dynamic characteristics of principal components; and signals and principal components are quantitatively analyzed by calculating signal energy. Results indicate that signal characteristics of the previous two principal components are apparent, based on which dynamic characteristics of chaotic signal can be extracted. Signal at the perpendicular direction of the table is significantly correlated with that at the horizontal motion direction, which indicates that they are excited from the same vibration source. However, signals perpendicular to each other in terms of the motion direction at the horizontal level are rarely correlated; the total signal energy is maximum at the motion direction, minimum at the horizontal non-motion direction, and medium at the perpendicular non-motion direction. Bending vibration of the lead screw at the perpendicular direction is far more violent than that at the horizontal direction.

关键词： Acceleration     vibration source     chaotic     energy     dynamic    

HTML PDF 收藏

Experimental investigations on operating characteristics of a closed loop pulsating heat pipe

Yu WANG

《能源前沿（英文）》 2015年 第9卷 第2期   页码 134-141 doi: 10.1007/s11708-015-0354-x

摘要： The operating mechanism of the pulsating heat pipe (PHP) is not well understood and the present technology cannot predict required design parameters for a given task. The aim of research work presented in this paper is to better understand the operation regimes of the PHP through experimental investigations. A series of experiments were conducted on a closed loop PHP with 5 turns made of copper capillary tube of 2 mm in inner diameter. Two different working fluids viz. ethanol and acetone were employed. The operating characteristics were studied for the variation of heat input, filling ratio (FR) and inclination angle of the tested device. The results strongly demonstrate the effect of the filling ratio of the working fluid on the operational stability and heat transfer capability of the device. Important insight into the operational characteristics of PHP has been obtained.

关键词： closed loop pulsating heat pipe     thermal performance     operation limit     thermography    

HTML PDF 收藏

Thermal and hydraulic characteristics of a large-scaled parabolic trough solar field (PTSF) under cloud

Linrui MA, Zhifeng WANG, Ershu XU, Li XU

《能源前沿（英文）》 2020年 第14卷 第2期   页码 283-297 doi: 10.1007/s11708-019-0649-4

摘要： To better understand the characteristics of a large-scaled parabolic trough solar field (PTSF) under cloud passages, a novel method which combines a closed-loop thermal hydraulic model (CLTHM) and cloud vector (CV) is developed. Besides, the CLTHM is established and validated based on a pilot plant. Moreover, some key parameters which are used to characterize a typical PTSF and CV are presented for further simulation. Furthermore, two sets of results simulated by the CLTHM are compared and discussed. One set deals with cloud passages by the CV, while the other by the traditionally distributed weather stations (DWSs). Because of considering the solar irradiance distribution in a more detailed and realistically way, compared with the distributed weather station (DWS) simulation, all essential parameters, such as the total flowrate, flow distribution, outlet temperature, thermal and exergetic efficiency, and exergetic destruction tend to be more precise and smoother in the CV simulation. For example, for the runner outlet temperature, which is the most crucial parameter for a running PTSF, the maximum relative error reaches −15% in the comparison. In addition, the mechanism of thermal and hydraulic unbalance caused by cloud passages are explained based on the simulation.

关键词： parabolic trough solar field (PTSF)     thermal hydraulic model     cloud passages     transients    

HTML PDF 收藏

Experimental research on dynamic operating characteristics of a novel silica gel-water adsorption chiller

WANG Dechang, WU Jingyi, WANG Ruzhu, DOU Weidong

《能源前沿（英文）》 2007年 第1卷 第3期   页码 347-351 doi: 10.1007/s11708-007-0052-4

摘要： A novel silica gel-water adsorption chiller consisting of two adsorption/desorption chambers and an evaporator with one heat-pipe working chamber is experimentally studied. The dynamic operating characteristics of the chiller and the thermodynamic characteristics of the adsorber are obtained. The experimental results show that the dynamic operating characteristics of the chiller and the thermodynamic characteristics of the adsorber are satisfactory and that the cycle is a novel and effective adsorption cycle. A mass recovery process increases the cyclic adsorption capacity of the system and improves adaptability of the chiller to a low-grade heat source. In addition, the experiment indicates that this novel chiller is highly suitable for an air conditioning system with a low dehumidification requirement or a system with a large cycle flowrate and an industrial cooling water system.

关键词： satisfactory     suitable     recovery     adsorption capacity     thermodynamic    

HTML PDF 收藏

Dynamic characteristics analysis of active constrained layer damping plate with various boundary conditions

Jing LU, Yu XIANG, Qiao NI

《机械工程前沿（英文）》 2011年 第6卷 第4期   页码 449-455 doi: 10.1007/s11465-011-0240-0

摘要：

Considering the direct and converse piezoelectric effect, expressions of piezoelectric membrane internal forces in the piezoelectric constrained layer were given. The control equations of the piezoelectric constrained layer and host plate were obtained in according with the thin plate theory. Based on the layer wised principle, the integrated first order differential equation of an active constrained layer damping (ACLD) plate was derived for the simply supported boundary condition. Then, this method was expanded to the ACLD plate with cantilever boundary condition by virtue of geometric analogy method. Employing the extended homogeneous capacity precision integration approach, a high precision semi-analytical method was proposed to analyze the dynamic characteristics of the ACLD plate with various boundary conditions. The comparison with the literature results has verified the accuracy and effectiveness of the present method.

关键词： active constrained layer damping (ACLD) plate     dynamic characteristics     semi-analytical method     extended homogeneous capacity precision integration approach    

HTML PDF 收藏

On the improvement design of dynamic characteristics for the roller follower of a variable-speed plate

Hui Ching FAN, Hong Sen YAN

《机械工程前沿（英文）》 2012年 第7卷 第1期   页码 5-15 doi: 10.1007/s11465-012-0310-y

摘要：

Without modifying the cam contour, a cam mechanism with a variable input speed trajectory offers an alternative solution to flexibly achieve kinematic and dynamic characteristics, and then decrease the follower’s residual vibration. Firstly, the speed trajectory of cam is derived by employing Bezier curve, and motion continuity conditions are investigated. Then the motion characteristics between the plate cam and its roller follower are derived. To analyze the residual vibration, a single degree of freedom dynamic model of the elastic cam-follower system is introduced. Based on the motion equation derived from the dynamic model, the residual vibration of the follower is yielded. The design procedure to improve the kinematic and dynamic motion characteristics is presented and two design examples with discussions are provided. Finally, the simulations of the kinematic and dynamic models by ADAMS are carried out and verified that the design models as well as the performances of the mechanism are feasible.

关键词： cam mechanism     variable input speed     kinematic design     dynamic design     optimal design    

HTML PDF 收藏

Theory analysis and system identification methods on thermal dynamics characteristics of ballscrews

XIA Junyong, HU Youmin, WU Bo, SHI Tielin

《机械工程前沿（英文）》 2008年 第3卷 第4期   页码 408-415 doi: 10.1007/s11465-008-0061-y

摘要： Empirical model of machine tools on thermal error has been widely researched, which can compensate for thermal error to some extent but not suitable for thermal dynamic errors produced by dynamic heat sources. The thermoelastic phenomenon of unidimensional heat transfer of ballscrews influenced by changeable heat sources is analyzed based on the theory of heat transfer. Two methods for system identification (the least square system identification and BP artificial neural network (ANN) system identification) are put forward to establish a dynamic characteristic model of thermal deformation of ballscrews. The model of thermal error of the axis in a feed system of DM4600 vertical miller is established with a fine identification effect. Comparing the results of the two identification methods, the BP ANN system identification is more precise than the least square system identification.

关键词： square system     network     vertical miller     transfer     ANN    

HTML PDF 收藏

Isogeometric analysis of coupled thermo-elastodynamic problems under cyclic thermal shock

Asghar AMANI DASHLEJEH

《结构与土木工程前沿（英文）》 2019年 第13卷 第2期   页码 397-405 doi: 10.1007/s11709-018-0473-7

摘要： The isogeometric analysis (IGA) method was extended for the solution of the coupled thermo-elastodynamic equations. The dimensionless formulation was accepted in discretization of the uncoupled and coupled thermoelasticity equations and the Generalized Newmark method was used in the time integration procedure. First, the performance of the proposed method was verified against a two-dimensional benchmark example subjected to constant thermal shock with available exact analytical solutions. Then a two-dimensional half-space benchmark example under thermal shock was solved. Finally, cyclic thermal shock (CTS) loading was applied on the half-space problem. The results dedicated that IGA can be used as a suitable approach in the analysis of the general thermomechanical problems.

关键词： isogeometric analysis     coupled thermo-elastodynamic     dynamic analysis     generalized newmark     cyclic thermal shock    

HTML PDF 收藏

Computational fluid dynamic analysis of flutter characteristics for self-anchored suspension bridges

ZHU Zhiwen, WANG Zhaoxiang, CHEN Zhengqing

《结构与土木工程前沿（英文）》 2008年 第2卷 第3期   页码 267-273 doi: 10.1007/s11709-008-0034-6

摘要： This paper outlines the essentials and procedures of computational fluid dynamics (CFD) simulation applicable to evaluating flutter derivatives of bridge decks. An arbitrary Lagrangian-Eulerian (ALE) description of the flow around the moving rigid box girder combined with the finite volume discretization and multi-grid algorithm is presented. The proposed methods are employed to identify flutter derivatives of the bridge deck of the Sanchaji Self-anchored Suspension Bridge. The results agree well with ones from wind tunnel tests. It demonstrates accuracy and efficiency of the present method.

关键词： discretization     computational     description     Self-anchored Suspension     simulation applicable    

HTML PDF 收藏

Thermal analysis of lubricated three-dimensional contact bodies considering interface roughness

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0672-8

摘要： Surface roughness and thermal action are of remarkable importance in the lubrication performance of mechanical components, especially in extreme conditions. However, available studies mainly focus on the full-film lubrication conditions without considering temperature rise and real 3D surface roughness due to the complexity of surface topography and temperature characteristics. Moreover, studies on the interfacial thermal behaviors of 3D rough surface lubricated contact in an extended range of working conditions remain limited. In this paper, a deterministic mixed thermal elastohydrodynamic lubrication model considering real 3D surface roughness and thermal effects is proposed. In this model, pressure and temperature are coupled with each other, the computation of elastic deformation is accelerated through the discrete convolution and fast Fourier transform method, the temperature field is calculated with the column sweeping technique, and the semi-system method is introduced to improve convergence and numerical stability under severe conditions. The model is validated by comparing its results with available published numerical and experimental results. The thermal behaviors of the contact interface are studied in a wide range of working conditions. The influences of surface roughness and thermal effect on lubrication performance are revealed. The results show that the proposed model can be used as a powerful analysis tool for lubrication performance and temperature prediction in various heavy-load, high-speed lubricated components over a wide range of lubrication conditions.

关键词： thermal elastohydrodynamic lubrication     surface roughness effect     thermal effect     temperature characteristics     severe conditions    

HTML PDF 收藏

标题 作者 时间 类型 操作

Transfer function solving, simulating and testing of thermal dynamics characteristics of a ballscrew

Junyong XIA, Bo WU, Youmin HU, Tielin SHI,

期刊论文

Numerical solution, simulation and testing of the thermal dynamic characteristics of ball-screws

XIA Junyong, HU Youmin, WU Bo, SHI Tielin

期刊论文

Numerical study of thermal characteristics of double skin facade system with middle shade

Shaoning LIU, Xiangfei KONG, Hua YANG, Minchao FAN, Xin ZHAN

期刊论文

Dynamic characteristics of molten droplets and hot particles falling in liquid pool

Liangxing LI, Weimin MA, Huixiong LI, Tingkuan CHEN,

期刊论文

Air-bearing position optimization based on dynamic characteristics of ultra-precision linear stages

CHEN Xuedong, LI Zhixin

期刊论文

Dynamic characteristics of NC table with SVD

WANG Linhong, WU Bo, DU Runsheng, YANG Shuzi

期刊论文

Experimental investigations on operating characteristics of a closed loop pulsating heat pipe

Yu WANG

期刊论文

Thermal and hydraulic characteristics of a large-scaled parabolic trough solar field (PTSF) under cloud

Linrui MA, Zhifeng WANG, Ershu XU, Li XU

期刊论文

Experimental research on dynamic operating characteristics of a novel silica gel-water adsorption chiller

WANG Dechang, WU Jingyi, WANG Ruzhu, DOU Weidong

期刊论文

Dynamic characteristics analysis of active constrained layer damping plate with various boundary conditions

Jing LU, Yu XIANG, Qiao NI

期刊论文

On the improvement design of dynamic characteristics for the roller follower of a variable-speed plate

Hui Ching FAN, Hong Sen YAN

期刊论文

Theory analysis and system identification methods on thermal dynamics characteristics of ballscrews

XIA Junyong, HU Youmin, WU Bo, SHI Tielin

期刊论文

Isogeometric analysis of coupled thermo-elastodynamic problems under cyclic thermal shock

Asghar AMANI DASHLEJEH

期刊论文

Computational fluid dynamic analysis of flutter characteristics for self-anchored suspension bridges

ZHU Zhiwen, WANG Zhaoxiang, CHEN Zhengqing

期刊论文

Thermal analysis of lubricated three-dimensional contact bodies considering interface roughness

期刊论文