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Cooling Performance for Cylindrical Film-Cooling Hole with Divided Downstream Crescent-Shaped Block

IOP Conference Series: Earth and Environmental Science 2020年第1期461卷

作者： Pengfei Zhang Zhiting Tong Fei Wang Linchao Bai Chao Zhang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin 300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin 300384 China

The cooling performances for the cylindrical film-cooling hole with divided downstream crescent-shaped blocks were numerically investigated in present study. Four configurations with divided crescent-shaped block, i.e. linear, 30° convergence, 30° expansion, and 30° curved expansion, were studied at typical flow conditions. The successive crescent-shaped block case and the no block case were also solved in comparison. The temperature profiles, the local and lateral averaged cooling effectiveness at blowing ratios of 0.5 to 1.5 were obtained. As compared with the successive block case, the lateral coolant coverage were widened by using the divided block, and thus the lateral averaged cooling effectiveness were improved, especially at higher blowing ratios. Comparatively, the cylindrical hole with 30° expansion crescent-shaped block exhibited highest cooling performance.

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The temperature control of blackbody radiation source based on ADRC 15

The temperature control of blackbody radiation source based ...

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15th IEEE International Conference on Mechatronics and Automation, ICMA 2018

作者： Wang, Zhigang Yun, Zerong Wang, Lingling Wang, Jinghui Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin China Tianjin University of Technology Tianjin China Natinal Institute of Metrology China Beijing China

ISBN: (纸本)9781538660720

Blackbody radiation source is used as a standard device for infrared thermometer, it plays increasingly important roles in the field of calibration. Through experiment discoveries that it is a typical nonlinear system and has a large transport delay when the blackbody is rise temperature or cooling in order to reach set temperature points. Based on the temperature control of blackbody is a kind of typical multi-variable, strong coupling and time-varying nonlinear control system. The paper proposes applying the theory of active disturbance rejection controller (ADRC) to suppress various disturbances and improve the dynamic performance of blackbody radiation source. First of all, describing the working principle of blackbody radiation source and building its mathematical model. Secondly, introducing the control method of ADRC, which is applied to the temperature control system of blackbody radiation source. Finally, through MATLAB/SIMULINK platform to simulate and compare the temperature control performances of blackbody among ADRC, PID and Smith predictor(SP) control strategies. The simulation results show that proposed ADRC algorithm improves the abilities of anti-interference of system and it is without overshoot. In addition, the results also indicated that the control method of ADRC shortens plant stable time and has a strong prospect for practical applications. © 2018 IEEE.

关键词： Temperature control

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Effect of tungsten on creep properties of martensitic 9Cr steel

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IOP Conference Series: Materials Science and Engineering 2020年第1期838卷

作者： F Y Hu S J Zhang J J Shen Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education (Tianjin University of Technology) China

The effects of tungsten on the creep behavior and microstructure of tempered martensite 9Cr steel with different W concentrations ranging from 0–2.5 wt% were studied. The matrix consisted of tempered lath martensite structure and M23C6 located along the grain boundary or inside the grain. As the W concentration increased, the number of M23C6 increased while the particle size decreased. Also, with the increasing W concentration, the minimum creep rate and elongation decreased while the time to rupture increased. The rise in W concentration led to the refinement of M23C6, which enhanced the creep strength but reduced the creep plasticity.

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Temperature control based on fuzzy-PID algorithm for the blackbody radiation source 15

Temperature control based on fuzzy-PID algorithm for the bla...

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15th IEEE International Conference on Mechatronics and Automation, ICMA 2018

作者： Wang, Zhigang Wang, Lingling Yun, Zerong Wang, Jinghui Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education China Tianjin University of Technology Tianjin China National Institute of Metrology China Beijing China

ISBN: (纸本)9781538660720

Blackbody radiation source is a key equipment in the traceability process of temperature measurement. In infrared temperature measurement, stable and consistent temperature control of the blackbody radiation sources is required. And in the process of calibration, it is a key element that a blackbody radiation source can produce a fixed temperature. Effective control of its temperature is, therefore, crucial. Due to the change of parameters and the uncertainty of loads, the performance requirements for conventional Proportional, Integral and Differential (PID) controller are high. But the control effect of the conventional PID controller on the temperature control system is not perfect. So the Fuzzy-PID control algorithm is simulated with software for the temperature control system of the blackbody radiation source in this paper. Compared with the conventional PID control algorithm, the Fuzzy-PID control has advantages of quicker response, smaller overshoot and more stable performance. It is of a certain reference value to improve the temperature control performances in the actual industrial production applications. © 2018 IEEE.

关键词： Temperature control

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Research on homoclinic orbits and homoclinic bifurcation motion in a typical triple-well potential vibration system 25

Research on homoclinic orbits and homoclinic bifurcation mot...

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25th International Congress on Sound and Vibration 2018: Hiroshima Calling, ICSV 2018

作者： Feng, Jingjing Zhang, Wei Lui, Haiying Hu, Wenhua Beijing University of Technology College of Mechanical Engineering Beijing Key Laboratory on Nonlinear Vibrations and Strength of Mechanical Structures Beijing China Tianjin University of Technology School of Mechanical Engineering Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin China Tianjin University of Technology National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin China

ISBN: (纸本)9781510868458

The pull-in phenomenon is an important sign of instable movement for electrostatic micro-resonators. In present paper, the problems of homoclinic orbits and homoclinic bifurcation motion in a typical triple-well potential system with non-Z2 symmetric and higher-order nonlinear terms are studied, which is used to describe corresponding nonlinear dynamical behaviors of pull-in and complex vibration phenomena in typical micro-resonator. For the complexity between the equilibrium points and the phase space curves in triple-well potential system, the non-Z2 symmetric homoclinic orbits that are corresponding to the pull-in phenomenon are discussed under a certain energy input condition. Because the fact of the air damping in the actual micro-resonator cannot be ignored, the autonomous system containing the damping terms is studied directly. The further improved Padé approximation method can be applied to directly obtain analytical expressions of special homoclinic orbits with completely non-Z2 symmetry in corresponding conservative system, which contain not only the conventional Z2 symmetric nonlinear terms, but also the non-Z2 symmetric and higher-order nonlinear terms. In addition, the phase diagrams and bifurcation parameter curves of homoclinic orbit in corresponding autonomous system are obtained when the homoclinic bifurcation occurs. The present method is valid by comparing with the phase diagrams of homoclinic orbits from numerical method. Copyright © (2018) by International Institute of Acoustics & *** rights reserved.

关键词： Numerical methods

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Optimization of the Circuit Parameter in Class-E Power Amplifier in the Two-coil Wireless Power Transfer system

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IOP Conference Series: Materials Science and Engineering 2020年第1期740卷

作者： Zhuang Sun Qing Liu Kun Li Bin Hu Haibo Zhao Yankai Shi Shijie Zhang Yang Liu Tianjin Key Laboratory of Film Electronic and Communication Device Tianjin University of Technology Tianjin China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education (Tianjin University of Technology) Tianjin China Tianjin Institute of Power Sources Tianjin China

In this paper, the circuit parameters of the Class-E power amplifier are investigated and optimized to achieve the maximum of output power and efficiency in a two-coil Wireless Power Transfer (WPT) system. The circuit is simulated with software named Saber. Working frequency, the value of capacitors and inductor, which has relationship with the output power and efficiency, are investigated during the simulation. With the simulation results, it is found that the frequency and the shunt capacitor need to be optimized for high performance of the wireless power transfer system.

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Primary resonance analysis and optimal design of microbeam resonator with variable cross section under electrostatic actuator 25

Primary resonance analysis and optimal design of microbeam r...

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25th International Congress on Sound and Vibration 2018: Hiroshima Calling, ICSV 2018

作者： Liu, Cheng Hao, Shuying Zhang, Kunpeng Feng, Jingjing Zhang, Wei Tianjin University of Technology School of Mechanical Engineering Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin China Tianjin University of Technology National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin China Beijing University of Technology College of Mechanical Engineering Beijing Key Laboratory on Nonlinear Vibrations and Strength of Mechanical Structures Beijing China

ISBN: (纸本)9781510868458

In this paper, the doubly clamped microbeam-based resonator which actuated by two electrodes is investigated. A section parameter is proposed to describe the microbeam variables in the upper and under section. The differential equation is derived by considering the influence of neutral surface tension and the nonlinearity of electrostatic force. The Galerkin and Newton Cotes methods are used to obtain reduced-order model. The nonlinear vibration behaviors of system at equilibrium point are analysed. First, the frequency response is obtained by the method of multi-scale (MMS). The relationship between section parameter and mechanical property of the microresonator is studied. Then, the system is optimized by considering the relationship between section parameter and the actual physical parameters. Finally, the finite element method through COM-SOL software is used to verify the theoretical results, and the two results are very close to each other in the stable region. The research results provide a good reference for the design of microresonator. © 25th International Congress on Sound and Vibration 2018, ICSV 2018: Hiroshima Calling. All rights reserved.

关键词： Resonators

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Influence of Micro-texture Parameters on Bone Drilling Force and Torque: A Finite Element Model

Influence of Micro-texture Parameters on Bone Drilling Force...

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2018 4th International Conference on Mechanical Engineering and Automation Science(ICMEAS2018)

作者： Yahui Hu Xiangjun Li Chuncheng Chen Lili Su QingchunZheng Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of Technology

The micro-texture on the tool surface is an effective way to improve the quality of the drilling. While high-performance micro-texture plays an important role in improving the quality of working surface and prolonging the life of tool. In this study, a three-dimensional finite element model was established to study the relationship between drilling thrust, torque and microstructure parameters(micro-pit depth, micro-pit diameter and micro-pit spacing) during drilling of cortical bone. The model was validated by cortical bone drilling using a micro-structured tool. On basis of this, the thrust and torque prediction models of the micro-texture parameters were obtained. The results indicate that the thrust and torque increased with the increase of micro-pit diameter;while the increase of the micro-pit spacing caused the thrust and torque to decrease. When the depth of the micro-pit increased, the thrust and torque decreased first and then increased, and we found that the effect of micro-pit spacing and micro-pit depth on force and torque is insignificant.

关键词： Influence of Micro-texture Parameters on Bone Drilling Force and Torque A Finite Element Model

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A compact terahertz CW HCN dual laser and its stability control 43

A compact terahertz CW HCN dual laser and its stability cont...

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43rd International Conference on Infrared Millimeter and Terahertz Waves, IRMMW-THz 2018

作者： Xie, J.X. Liu, H.Q. Shen, J.J. Wei, X.C. Jie, Y.X. School of Mechanical Engineering Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechanical System Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology China Institute of Plasma Physics Chinese Academy of Sciences Hefei230031 China

ISBN: (纸本)9781538638095

A compact terahertz continuous wave (CW) discharge-pumped Hydrogen cyanide (HCN) dual laser has been developed for better signal to noise ratio and higher time resolution, with active power and intermediate frequency (IF) control. The output power of about 110 mW on the 0.89 THz line has been obtained with 1 m long and 50 mm inner diameter dual discharge-pumped wave-guides laser. An output-power and IF feedback control system is applied to the HCN dual laser for output power and IF stability. This feedback system consists of two stepping motors, a piezoelectric ceramics (PZT), a PLC, a supervisory computer and the corresponding control program. The whole feedback control system can successful in stabilizing the power of the laser around 110 mW and the IF at around 1MHz in several hours. © 2018 IEEE.

关键词： Signal to noise ratio

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Detection of Weld Defects Based on Incremental Two-Dimensional Principal Component Analysis

Detection of Weld Defects Based on Incremental Two-Dimension...

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IEEE International Conference on Mechatronics and Automation

作者： Yaohua Shen Weimin Ge Xiaofeng Wang School of Mechanical Engineering Tianjin University of Technology Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechanical System Tianjin China

Aiming at the requirements of the real-time detection of weld defects in the industry, the candid covariance-free incremental PCA (CCIPCA) algorithm was introduced into the Two-Dimensional Principal Component Analysis (2PCA) algorithm, therefore an incremental 2DPCA algorithm (I2DPCA) is proposed. Firstly, the images captured by camera are preprocessed to improve the quality of the images because the captured images might be affected in the process of image acquisition. Then the 12DPCA algorithm is used to achieve feature extraction, and the dimension of the images is reduced. Finally, the recognition of weld defects is implemented using the k-nearest neighbor algorithm (KNN). Compared with the methods of traditional recognition by extracting the sizes of several geometric defects, the proposed algorithm has the advantage of the small memory spaces, the high recognition rate and the strong real-time recognition. The experimental results show that the proposed algorithm has higher recognition rate and is more practical than the 2DPCA, and the recognition rate reaches 94%, which can meet the requirements of the real-time detection.

关键词： Welding Feature extraction Covariance matrices Principal component analysis Histograms Image recognition Low pass filters

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