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temperature field simulation of polyolefin-absorber mixture by FDTD-FDM model during microwave heating

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Chinese Journal of Chemical Engineering 2020年第11期28卷 2900-2917页

作者： Xiaodong Jing Hao Wen Zhihong Xu State Key Laboratory of Multiphase Complex Systems Beijing Engineering Research Centre of Process Pollution ControlInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

This work has performed a numerical simulation of the temperature field during microwave heating of polyolefin-absorber mixture by means of a combined electric and thermal model.A finite difference time domain was used to model the electric field distribution within the cavity,while the finite difference method was used to calculate the temperature field distribution in different *** study has focused only on the process from room temperature to 500 K for reducing heating time and energy *** temperature range is a process with high energy consumption,difficult to control and great influence on the follow-up *** dependence of dielectric properties and thermal properties of heated materials are fully considered and simulated through an iterative *** simulation results show that input power,the size and location of the heated materials,the position of the waveguide,and the kinds of microwave absorbers are important factors affecting the heating *** a result,the uniform temperature distribution(the temperature difference Tdb10 K)can be achieved by choosing the appropriate input power(500–2000 W),the appropriate proportion of microwave absorber(the volume ratio of Si C to HDPE is 30:70),and combining with the moving and rotating of the heated *** uniform temperature field obtained without mechanical stirring is very important for reducing energy consumption and subsequent reactions.

关键词： Microwave heating temperature field Finite difference time domain Finite difference method

temperature field Simulation and Experimental Study of Anti‑backlash Single‑Roller Enveloping Hourglass Worm Gear

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Chinese Journal of Mechanical Engineering 2020年第4期33卷 77-86页

作者： Shisong Wang Shike Wang Jie Wang Xingqiao Deng School of Mechanical Engineering Xihua UniversityChengdu 611730China College of Nuclear Technology and Automation Engineering Chengdu University of TechnologyChengdu 610059China

In gear transmission,temperature rise has a non-negligible impact on the accuracy,noise and transmission ***,there is no relevant research on the temperature rise of the anti-backlash single-roller enveloping hourglass worm(ASEHW)*** solve this problem,based on tribology principle and Hertz contact theory,the thermal power calculation method of the ASEHW gear was proposed for the first time and thermal analysis was carried out by Ansys *** bulk temperature of the ASEHW gear under four different rotating speed(300 r/min,600 r/min,900 r/min,1200 r/min)is *** main factors causing temperature rise of the ASEHW gear are analyzed ***,an experimental study is performed to verify the simulation results and validate the theory *** theory presented in this paper provides a solution for the thermal power calculation of ASEHW *** research provides a theoretical basis for further optimization of ASEHW gear.

关键词： Roller enveloping hourglass worm gear Finite element analysis temperature field

temperature field at time of pulse current discharge in metal structure with elliptical embedding crack

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Applied Mathematics and Mechanics(English Edition) 2008年第7期29卷 961-966页

作者：付宇明田振国郑丽娟李伟 College of Mechanical Engineering Yanshan University

Theoretical analysis is made on the temperature field at the time of pulse current discharge in a metal structure with an elliptical embedding crack. In finding the temperature field, analogy between the current flow through an elliptical embedding crack and the fluid flow through a barrier is made based on the similarity principle. Boundary conditions derived from this theory are introduced so that the distribution of current density and the temperature field expressions can be obtained. The study provides a theoretic basis to the applications of stopping spatial crack with electromagnetic heating.

关键词： embedding crack crack arrest temperature field pulse current discharge electro-magnetic heating effect

temperature field for Improving Internal Quality of Stretched Round Billet

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Journal of Iron and Steel Research International 2009年第6期16卷 17-22页

作者： QIU Ping XIAO Hong Mechanical Engineering College Yanshan University Qinhuangdao 066004 Hebei China

Based on the rigid-plastic theory, using a coupled thermomechanical model, the stretching process of a circular section billet is simulated by means of FEM software Deform-2D. Through the distribution of internal stress fields of stretched round billet, it is found that the shear stress field is the main factor to induce Mannesmann＇s effect. The simulation results show that a reasonable distribution of the temperature field may improve the internal quality of the circular section billet in the stretching process.

关键词： stretching temperature field Mannesmann's effect simulation

temperature field prediction of steel-concrete composite decks using TVFEMD-stacking ensemble algorithm

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第9期25卷 732-748页

作者： Benkun TAN Da WANG Jialin SHI Lianqi ZHANG School of Civil Engineering Changsha University of Science&TechnologyChangsha 410114China School of Civil and Architecture Engineering Hunan University of Arts and ScienceChangde 415000China School of Civil Engineering Central South University of Forestry and TechnologyChangsha 410004China

This research aims to develop an advanced deep learning-based ensemble algorithm,utilizing environmental temperature and solar radiation as feature factors,to conduct hourly temperature field predictions for steel-concrete composite decks(SCCDs).The proposed model comprises feature parameter lag selection,two non-stationary time series decomposition methods(empirical mode decomposition(EMD)and time-varying filtering-based empirical mode decomposition(TVFEMD)),and a stacking ensemble prediction *** validate the proposed model,five machine learning(ML)models(random forest(RF),support vector regression(SVR),multilayer perceptron(MLP),gradient boosting regression(GBR),and extreme gradient boosting(XGBoost))were tested as base learners and evaluations were conducted within independent,mixed,and ensemble ***,predictions are made based on engineering *** results indicate that consideration of lag variables and modal decomposition can significantly improve the prediction performance of learners,and the stacking framework,which combines multiple learners,achieves superior prediction *** proposed method demonstrates a high degree of predictive robustness and can be applied to statistical analysis of the temperature field in *** time lag features helps account for the delayed heat dissipation phenomenon in concrete,while decomposition techniques assist in feature extraction.

关键词： Steel-concrete composite deck(SCCD) temperature field Time-varying filtering-based empirical mode decomposition(TVFEMD) Feature selection Machine learning(ML)

temperature field Analysis and Adaptive Neuro-fuzzy Inference System for MgO Single Crystal Production

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Journal of Wuhan University of Technology(Materials Science) 2012年第6期27卷 1089-1095页

作者：李铁 WANG Zhen 王宁会 School of Electrical Engineering Dalian University of Technology

The temperature field in MgO single crystal furnace is crucial to grow high-purity MgO single crystals with large sizes. In order to build proper temperature gradient, firstly finite element method （FEM） was used to study the temperature field distributions, and then a temperature controller with adaptive neuro- fuzzy inference system （ANFIS） was developed based on the result of FEM and practical experiences. When the temperature in MgO single crystal furnace was changed, the controller would regulate the positions of three- phase electrodes and the voltage of the power simultaneously. The experimental results indicate that using the adaptive neuro-fuzzy control system can improve the quality and the quantity of the MgO single crystal production.

关键词： finite element analysis MgO single crystals furnace temperature field ANFIS

temperature field in Laser Line Scanning Thermography: Analytical Calculation and Experiment

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Computer Modeling in Engineering & Sciences 2023年第10期137卷 1001-1018页

作者： Yin Li Yuanjia Song Zhengwei Yang Haijun Jiang Bowen Liu China Aerodynamics Research and Development Center Mianyang621000China Xi’an Research Institute of High Technology Xi’an710025China Nanjing Novelteq Ltd.Nanjing210038China

The temperature field in laser line scanning thermography is investigated comprehensively in this work,including analytical calculation and ***,the principle of laser line scanning thermography is *** this basis,a physical laser line scanning model is ***,based on Fourier transform(FT)and segregation variablemethod(SVM),the heat conduction differential equation in laser line scanning thermography is derived in *** temperature field of the composite-based coatings model with defects is simulated *** results show that the laser line scanning thermography can effectively detect the defects in the *** correctness of the analytical calculation is verified by comparing the surface temperature distribution obtained by analytical calculation and numerical ***,an experiment is carried out and the changeable surface temperature obtained by analytical calculation is compared with the experimental *** shows that the error of maximum temperature obtained by analytical calculation and by experiment is 8%with high accuracy,which proves the correctness of analytical calculation and enriches the theoretical foundation of laser line scanning thermography.

关键词： temperature field laser line scanning thermography analytical calculation numerical simulation experiment

temperature field analysis of two rotating and squeezing steel-rubber rollers

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High Technology Letters 2017年第4期23卷 410-417页

作者：初红艳 Xu Kangjian Huang Wei Cai Ligang Advanced Manufacturing Technology of Beijing Key Laboratory College of Mechanical Engineering and Applied Electronics TechnologyBeijing University of TechnologyBeijing 100124P.R.China Wuhan Zhongyuan Electronics Group Co.Ltd Wuhan 430205P.R.China

Rubber has strong nonlinear viscoelastic characteristic. Under effect of the periodically changing external force,it will show the phenomenon of lagging deformation and mechanical loss,which means deformation lags behind stress changes and the situation of loss of work is caused by the hysteresis. Loss of work will be transformed into thermal energy and makes the temperature of rubber and the object in contact with it rise,which will thereby affect the dynamic characteristics of the structure. Based on a pair of mutual rotating and squeezing steel-rubber rollers as the research object,the finite element simulation software Ansys is used in this paper to analyze the temperature field of the structure. As a result,temperature distribution characteristics of two directions are obtained. One is squeezing area along the direction of the wall,the other is along the direction of thickness of rubber. Then the influence of the rotating speed and the pressure between two rollers on temperature of rubber is analyzed. The temperature experiment of mutual squeezing contact steelrubber roller is carried out on the experimental platform via using infrared thermal imager and infrared thermometer. The experiment data are in accordance with the simulation results on regulation of temperature distribution as well as high degree of similarity on value,which shows the effectiveness of simulation. Research results are of great significance for temperature characteristic analysis of rubber structure.

关键词： rubber viscoelasticity mechanical loss squeezing contact temperature field

temperature field analysis of main steam pipe under local post weld heat treatment

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China Welding 2010年第4期19卷 20-24页

作者：李培麟樊睿智陆皓 School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai 200240

In local post weld heat treatment, the temperature difference is the criterion of the process. The temperature field in the main stream pipe under local post weld heat treatment is simulated by finite element method. A close-loop control program is designed to simulate the temperature field of two different pipes. Both the skin effect of induction heating and electro-thermal coupled effect are considered in the heating model. The local heat treatment temperature difference at the inner and outer side of the pipe is analyzed and the different convection conditions are also considered. The simulation results show that in appropriate induction heating process, the temperature difference in the pipe can be controlled within 30 ℃.

关键词： local post weld heat treatment temperature field electro-thermal coupling numerical simulation