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Dynamic Investigation on Composite Flexible Multi-body System Considering thermal effect

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Journal of Shanghai Jiaotong university(Science) 2010年第4期15卷 414-422页

作者：潘科琪刘锦阳 School of Naval Architecture Ocean and Civil EngineeringShanghai Jiaotong University

The dynamic performance of composite flexible multi-body system under the simultaneous action of thermal fields and driving constraint is analyzed. Based on strain-displacement relation of the Mindlin plate theory which includes transverse shear deformation, and considering thermal effect, variation equations of laminated plate are derived by the principle of virtual work. The finite element method is used for discretization. According to kinematics constraint relation, dynamic equations for spatial slider-crank system are established. Simulation results show that spatial deformation （torsion deformation） appears in the multi-layered composite slider-crank mechanism which is simulated with planar motions. Furthermore, the influence of coupling between thermal expansion and flexible deformations of non-symmetrical composite plates on the large overall motion under the uniform temperature field is investigated. Finally, significant change in constraint force due to the spatial deformation is shown.

关键词： flexible multi-body system composite plate thermal effect spatial deformation

Calculation and Comparison of thermal effect in Laser Diode pumped Slab Lasers with Different Pumping Structures

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Calculation and Comparison of Thermal Effect in Laser Diode ...

Research on High-temperature thermal effect Laws and Thermodynamic Characteristics of Salt Rock

2007亚洲光电子会议半导体激光器及应用分会场

作者： Feng HUANG* Nan JIANG Yuefeng WANG Wei DONG Yanxiong NIU Teaching & Research Section of Optics Engineering Ordnance Engineering College Shijiazhuang China 050003

Laser diode （LD） pumped slab laser, as an important high average power solid-state laser, is a promising laser source in military and industrial fields. The different laser diode pumping structures lead to different thermal effect in the slab gain medium. The thermal and stress analysis of slab laser with different pumping structure are performed by finite element analysis （FEA） with the software program ANSYS. The calculation results show that the face pumped and cooled laser results in a near one-dimension temperature distribution and eliminates thermal stress induced depolarization. But the structure is low pump efficiency due to the small thickness of slabs and the requirement to cool and pump through the same faces. End-pumped slab laser is high pump efficiency and excellent mode match, but its pumping arrangement is fairly complicated. The edge-pumped face-cooling slab laser’s pump efficiency is better than face-pumping, and its pumping structure is simpler than end-pumped laser, but the tensile stress on surfaces may initiate failure of the gain medium so it is important to design so that the stress is well below the stress fracture limit. The comparison of the thermal effects with different pumping structure shows that, the edge-pumped slab laser has engineering advantages in high power slab laser’s application. Furthermore, the end-pumped slab laser tends to get the best beam quality, so it is fit for the application which has a special requirement on laser beam quality.

关键词： LD pumped solid-state laser slab laser pump structure thermal effect temperature distributing thermal stress distributing

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Research on High-temperature Thermal Effect Laws and Thermod...

Efficient activation of the Co/SBA-15catalyst by high-frequency AC-DBD plasma thermal effects for toluene removal

2012年海峡两岸破坏科学/材料试验学术会议

作者： JIANG Kai-le LI Yun-peng ZHENG Ya-li ZHANG Hua-bin College of Mechanical and Transportation Engineering China University of Petroleum Research Institute of Petroleum Exploration & Development

Accumulation and explosion of thermal energy have a potential influence on mechanical parameters and strength of salt rock in the process of gas injection and *** this study,thermal properties at high temperature were determined through experimental research. The relation between stress and strain,mechanical parameters,and the law of thermal effects were investigated through nonlinear thermodynamics *** researches shown that strength measured by conventional triaxial compression test under different confining pressure raised with the increase of temperature,the strength raised with the increase of confining pressure at the same *** addition,the strength are affected by physical parameters of salt rock.A nonlinear relation was appeared between thermal coefficient and *** in this paper have a reference value to deeply research of mechanical properties of salt rock and engineering project of salt-cavern gas storage.

关键词： Salt Rock High Temperature thermal effect thermal Coefficient Triaxial Compression Tes

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Plasma Science and Technology 2024年第8期26卷 84-94页

作者：李越姜楠刘政妍秦亮彭邦发王荣刚孙玉荣李杰 School of Environment Dalian University of TechnologyDalian 116024People’s Republic of China School of Electrical Engineering Dalian University of TechnologyDalian 116024People’s Republic of China College of Electrical and Power Engineering Taiyuan University of TechnologyTaiyuan 030024People’s Republic of China Canmax Technologies Co. Ltd.Suzhou 215121People’s Republic of China

Dielectric barrier discharge(DBD)plasma excited by a high-frequency alternating-current(AC)power supply is widely employed for the degradation of volatile organic compounds(VOCs).However,the thermal effect generated during the discharge process leads to energy waste and low energy utilization *** this work,an innovative DBD thermally-conducted catalysis(DBD-TCC)system,integrating high-frequency AC-DBD plasma and its generated thermal effects to activate the Co/SBA-15 catalyst,was employed for toluene ***,Co/SBA-15 catalysts are closely positioned to the ground electrode of the plasma zone and can be heated and activated by the thermal effect when the voltage exceeds 10 k ***12.4 k V,the temperature in the catalyst zone reached 261℃ in the DBD-TCC system,resulting in an increase in toluene degradation efficiency of 17%,CO_(2)selectivity of 21.2%,and energy efficiency of 27%,respectively,compared to the DBD system *** contrast,the DBD thermally-unconducted catalysis(DBD-TUC)system fails to enhance toluene degradation due to insufficient heat absorption and catalytic activation,highlighting the crucial role of AC-DBD generated heat in the activation of the ***,the degradation pathway and mechanism of toluene in the DBD-TCC system were *** work is expected to provide an energy-efficient approach for high-frequency AC-DBD plasma removal of VOCs.

关键词： high-frequency alternating-current power thermal effect dielectric barrier discharge toluene degradation Co/SBA-15 catalysts

The action mechanism of the work done by the electric field force on moving charges to stimulate the emergence of carrier generation/recombination in a PN junction

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1001-1014页

作者： Lingyun GUO Yizhan YANG Wanli YANG Yuantai HU Department of Mechanics School of Aerospace EngineeringHubei Key Laboratory of Engineering Structural Analysis and Safety AssessmentHuazhong University of Science and TechnologyWuhan 430074China

It is discovered that the product of the current and the electric field in a PN junction should be regarded as the rate of work(power)done by the electric field force on moving charges(hole current and electron current),which was previously misinterpreted as solely a Joule heating *** clarify that it is exactly the work done by the electric field force on the moving charges to stimulate the emergence of non-equilibrium carriers,which triggers the novel physical *** regards to Joule heat,we point out that it should be calculated from Ohm’s law,rather than simply from the product of the current and the electric *** on this understanding,we conduct thorough discussion on the role of the electric field force in the process of carrier recombination and carrier *** thermal effects of carrier recombination and carrier generation followed are incorporated into the thermal equation of *** present study shows that the exothermic effect of carrier recombination leads to a temperature rise at the PN interface,while the endothermic effect of carrier generation causes a temperature reduction at the *** two opposite effects cause opposite heat flow directions in the PN junction under forward and backward bias voltages,highlighting the significance of managing device heating phenomena in design ***,this study possesses referential significance for the design and tuning on the performance of piezotronic devices.

关键词： piezoelectric semiconductor(PS) work done by electric field force thermal effect piezotronic device resistivity conductivity

thermal effectS OF BUILDING′S EXTERNAL SURFACES IN CITY——Characteristics of Heat Flux into and out of External Wall Surfaces

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Chinese Geographical Science 2004年第4期14卷 343-349页

作者： ZHANGYi-ping HEYun-ling LIUYu-hong MAYou-xin LIYou-rong DOUJun-xia XishuangbannaTropicalBotanicalGarden ChineseAcademyofScieneesKunming650223P.R.China XishuangbannaTropicalBotanicalGarden ChineseAcademyofScieneesKunming650223P.R.China／／GraduateSchoolofChineseAcademyofSciencesBeijing100039P.R.China ResearchCenterforEco-environmentalSciences ChineseAcademyofSciencesBeij＇ing100085P.R.China

This study examined the thermal effects of building′s external wall surfaces, using observational data of spatial-temporal distribution of surface temperature, air temperature, and heat flux into and out of external surface. Results indicate that external wall surface temperature and nearby air temperature vary with the change of orientation, height and season. In general, the external wall surface temperature is lower near the ground, and is higher near the roof, than nearby air temperature. But north wall surface temperature is mostly lower than nearby air temperature at the same height; south wall surface temperature during the daytime in December, and west wall surface temperature all day in August, is respectively higher than nearby air temperature. The heat fluxes into and out of external wall surfaces show the differences that exist in the various orientations, heights and seasons. In December, south wall surface at the lower sites emits heat and north wall surface at the higher sites absorbs heat. In April, all external wall surfaces, emit heat near the ground and absorb heat near the roof. In August, west wall surface all day emits heat, and other wall surfaces just show the commensurate behavior with that in April.

关键词： external wall surface thermal effect heat flux intensity spatial-temporal distribution

Surface,Size and thermal effects in Alkali Metal with Core-Electron Binding-Energy Shifts

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Chinese Journal of Chemical Physics 2021年第5期34卷 628-638,I0003,I0004页

作者： Wen-huan Zhu Zhong-kai Huang Mao-lin Bo Jin Huang Cheng Peng Hai Liu National Key Laboratory of Science and Technology on Micro/Nano Fabrication Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Inorganic Special Functional Materials of Chongqing Yangtze Nromal UniversityChongqing 408100China Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing Yangtze Normal UniversityChongqing 408100China School of Chemistry and Chemical Engineering Southwest UniversityChongqing 400715China Key Laboratory of Advanced Display and System Applications of Ministry of Education Shanghai UniversityShanghai 200072China

Consistency between density functional theory calculations and X-ray photoelectron spectroscopy measurements confirms our predications on the undercoordination-induced local bond relaxation and core level shift of alkali metal,which determine the surface,size and thermal properties of ***-resolved photoelectron spectroscopyanalysis method and bond order-length-strength theory can be utilized to quantify the physical parameters regarding bonding identities and electronic property of metal surfaces,which allows for the study of the core-electron binding-energy shifts in alkali *** employing these methods and first principle calculation in this work,we can obtain the information of bond and atomic cohesive energy of under-coordinated atoms at the alkali metal *** addition,the effect of size and temperature towards the binding-energy in the surface region can be seen from the view point of Hamiltonian perturbation by atomic relaxation with atomic bonding.

关键词： Alkali metal First principle calculation Metal surface Binding-energy Size effect thermal effect

Rapid solution for analysis of nonlinear fluid film force and dynamic behavior of a tilting-pad journal bearing-rotor system with turbulent and thermal effects

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Friction 2020年第2期8卷 343-359页

作者： Yingze JIN Zhaoyang SHI Xiaojing ZHANG Xiaoyang YUAN Key Laboratory of the Education Ministry for Modem Design and Rotor-Bearing Systems Xi'an Jiaotong UniversityXi'an 710049China

To analyze the nonlinear dynamics of a tilting-pad journal bearing(TPJB)-rotor system with high accuracy and speed,the database method(DM)is modified to rapidly determine the nonlinear fluid film force(NFFF)of a TPJB while considering turbulent and thermal effects.A high-accuracy,large-capacity NFFF database for a single pad is constructed by numerically solving the turbulent adiabatic hydrodynamic model for five equivalent state variables of the journal,which are discretized in the pad *** remaining variables are not discretized in the DM.A combined linear and parabolic interpolation polynomial based on the database is established to accurately calculate the NFFF of the tilting pads;thus,the NFFF of a four-pad TPJB is obtained in the bearing *** DM is applied to analyze and compare the nonlinear dynamic behavior of a water-lubricated TPJB-Jeffcott rotor system with and without turbulent and thermal *** present DM solution without these effects and the previous DM solution are shown to be *** results demonstrate the importance of the flow regime and the negligibility of temperature increases in the nonlinear dynamics of a water-lubricated *** work contributes to the accurate and efficient analysis of the nonlinear dynamics of high-speed TPJBs and low-viscosity-fluid-lubricated TPJBs.

关键词： tilting-pad journal bearing nonlinear fluid film force rotor dynamics turbulent flow thermal effect

Mechanism analysis and evaluation of thermal effects on the operating point drift of servo valves

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2022年第4期23卷 286-302页

作者： Jian KANG Zhao-hui YUAN Jing-chao LI School of Automation Northwestern Polytechnical UniversityXi’an710072China

Operating point drift over large temperature spans can significantly degrade the performance of servo *** direction and magnitude of the deviation of the operating point are *** analyze and evaluate the mechanism of this complex system with a multi-level structure and multi-variables,it is necessary to construct a theoretical model with a clear physical concept to describe ***,since the physical processes contain complex variations of structural parameters and flow properties,there is a problem of simplifying approximations in deriving analytical mathematical *** advantages of multi-physics field numerical analysis can compensate for this shortcoming of analytical *** on this,we constructed a whole-valve transfer function model to realize the mechanism analysis and evaluate the operating point drift when a thermal effect acts on a servo *** results show that the asymmetric fit relationship between the armature-nozzle assemblies is an important reason for the drift of the operating point caused by the thermal *** in structural parameters and fluid medium characteristics at different temperatures lead to nonlinear changes in the operating *** the deviation angle reaches±1°,an increase in temperature will cause the absolute value of the tangent slope of the displacement deviation of the spool to decrease from 1.44×10^(−5) m/℃to 1.25×10^(−6) m/℃.The influence of the deviation angle is reflected in the change in the absolute value of the tangent slope of the pressure deviation from 1.14×10^(3) Pa/℃to 110 Pa/℃.

关键词： Servo valve Operating point drift Mathematical model Numerical analysis thermal effect