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Building Simulation 2023年第1期16卷 51-67页

作者： Yanfeng Liu Ting Mu Xi Luo School of Building Services Science and Engineering Xi'an University of Architecture and TechnologyXi'an 710055China State Key Laboratory of Green Building in Western China Xi'an 710055China

Northwest China has abundant solar energy resources and a large demand for winter heating.Using solar energy for centralized heating is a clean and effective way to solve local heating problems.While present studies usually decoupled solar heating stations and the heating network in the optimization design of centralized solar heating systems,this study developed a joint multi-objective optimization model for the equipment capacity and the diameters of the heating network pipes of a centralized solar district heating system,using minimum total life cycle cost and CO_(2)emission of the system as the optimization objectives.Three typical cities in northwest China with different solar resource conditions(Lhasa,Xining,and Xi'an)were selected as cases for analysis.According to the results,the solar heating system designed using the method proposed in this study presents lower economic cost and higher environmental protection in comparison to separately optimizing the design of the solar heating station and the heating network.Furthermore,the solar fraction of the optimal systems are 90%,70%,and 31%for Lhasa,Xining,and Xi'an,and the minimum water supply temperatures are 55℃,50℃,and 65℃for an optimal economy and 55℃,45℃,and 45℃for optimal environmental protection,respectively.It was also established that the solar collector price has a greater impact on the equipment capacity of the solar heating station than the gas boiler price.

关键词： solar energy solar energy system district heating optimization design genetic algorithm

optimization design and test of rice plug seedling transplanting mechanism of planetary gear train with incomplete eccentric circular gear and non-circular gears

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International Journal of Agricultural and Biological Engineering 2017年第6期10卷 43-55页

作者： Ye Bingliang Yi Weiming Yu Gaohong Gao Yang Zhao Xiong Faculty of Mechanical Engineering and Automation Zhejiang Sci-Tech UniversityHangzhou 310018China Zhejiang Province Key Laboratory of Transplanting Equipment and Technology Hangzhou 310018China

In order to solve the problem of the high-speed mechanized transplanting of rice plug seedlings,the design requirements of transplanting mechanism for rice plug seedlings were analyzed and a kind of rice plug seedling transplanting mechanism of planetary gear train based on the drive with incomplete eccentric circular gear and non-circular gears was designed innovatively.The laboratory kinematics was examined.The working principle of the transplanting mechanism for rice plug seedlings was studied,kinematics analysis of the transplanting mechanism was carried out and its kinematic model was set up.A human-computer interaction optimization method was used to optimize the parameters of the transplanting mechanism.The computer aided analysis and optimization software of the transplanting mechanism based on Visual Basic 6.0 was developed.Through analyzing the influence of design variables on the optimization objectives of the transplanting mechanism,a set of parameters of the transplanting mechanism which meet the requirements of transplanting trajectory and posture for transplanting rice seedlings were obtained by means of human-computer interaction.The structure of the transplanting mechanism was designed according to this set of parameters,and its virtual prototype and physical prototype were set up and manufactured,respectively.The kinematic simulation test and high-speed photography kinematic test of the transplanting mechanism were conducted to obtain its kinematic performances,such as transplanting trajectory and posture.The results of bench test,simulation analysis and theoretical analysis were almost in agreement,which verified the correctness of the theoretical model and design results of the transplanting mechanism,indicating that the optimized transplanting mechanism can satisfy the requirements of transplanting rice seedlings and be applied in the rice plug seedling transplanter.

关键词： plug seedling transplanting mechanism incomplete eccentric circular gear non-circular gear planetary gear train optimization design

A novel matrix topology-based analysis method of thermal circuits for reliability optimization of HSER

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Chinese Journal of Aeronautics 2024年第4期37卷 479-492页

作者： Huimin LIANG Bo LI Jiaxin YOU Shan JIANG Mengtong ZHU Aobo WANG Department of Electrical Engineering Harbin Institute of TechnologyHarbin 150001China Nanjing Research Institute of Electronics Technology Nanjing 210008China

Hermetically Sealed Electromagnetic Relay(HSER), used in aviation and aerospace,demands high reliability due to its critical applications. Given its complex operating conditions, efficient thermal analysis is essential for optimizing reliability. The commonly used Finite Element Method(FEM) is often time-consuming and may not be efficient or adaptable for complex multi-dimensional system calculations and design processes. This paper introduces an analysis method for thermal networks based on matrix perspective technology, encompassing matrix transformation, backpropagation of the heat path model, temperature rise calculation, solution comparison, and product implementation. Using the similarity theory of heat circuits, a basic thermal unit is established. Based on the fundamental connection between key components, a thermal network for a typical HSER is designed. An experimental system is set up, and the thermal network model's accuracy is confirmed using test data. Employing the topology analysis method, the topology of the thermal network is analyzed under both coil-energized and de-energized states. Potential thermal paths are identified, leading to optimized solutions for the HSER. Utilizing these solutions, the thermal path matrix topology model is backpropagated to the thermal path for temperature rise calculations. When compared to prototype HSER test data, the efficiency and accuracy of this matrix topology-based analysis method are confirmed.

关键词： Thermal networks HSER(Hermetically Sealed Electromagnetic Relay) Heat-circuit topology model Heat-circuit matrix optimization design

optimization design on breakdown voltage of AlGaN/GaN high-electron mobility transistor

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Journal of Semiconductors 2016年第12期37卷 40-44页

作者：刘阳柴常春史春蕾樊庆扬刘彧千 School of Microelectronics Xidian UniversityKey Laboratory of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices

Simulations are carried out to explore the possibility of achieving high breakdown voltage of Gain HEMT （high-electron mobility transistor）. GaN cap layers with gradual increase in the doping concentration from 2 x 10^16 to 5 x 10^19 cm-3 of N-type and P-type cap are investigated, respectively. Simulation results show that HEMT with P-doped GaN cap layer shows more potential to achieve higher breakdown voltage than N-doped GaN cap layer under the same doping concentration. This is because the ionized net negative space charges in P-GaN cap layer could modulate the surface electric field which makes more contribution to RESURF effect. Furthermore, a novel GaN/A1GaN/GaN HEMT with P-doped GaN buried layer in GaN buffer between gate and drain electrode is proposed. It shows enhanced performance. The breakdown voltage of the proposed structure is 640 V which is increased by 12% in comparison to UID （un-intentionally doped） GaN/A1GaN/GaN HEMT. We calculated and analyzed the distribution of electrons＇ density. It is found that the depleted region is wider and electric field maximum value is induced at the left edge of buried layer. So the novel structure with P-doped GaN buried layer embedded in GaN buffer has the better improving characteristics of the power devices.

关键词： GaN HEMT optimization design breakdown voltage cap layer

optimization design of foundation excavation for Xiluodu super-high arch dam in China

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Journal of Rock Mechanics and Geotechnical Engineering 2015年第2期7卷 120-135页

作者： Qixiang Fan Shaowu Zhou Ning Yang China Three Gorges Corporation

With better understanding of the quality and physico-mechanical properties of rocks of dam foundation,and the physico-mechanical properties and structure design of arch dam in association with the foundation excavation of Xiluodu arch dam,the excavation optimization design was proposed for the foundation surface on the basis of feasibility study.Common analysis and numerical analysis results demonstrated the feasibility of using the weakly weathered rocks III1and III2as the foundation surface of super-high arch dam.In view of changes in the geological conditions at the dam foundation along the riverbed direction,the design of extending foundation surface excavation area and using consolidating grouting and optimizing structure of dam bottom was introduced,allowing for harmonization of the arch dam and foundation.Three-dimensional(3D)geomechanics model test and fi nite element analysis results indicated that the dam body and foundation have good overload stability and high bearing capacity.The monitoring data showed that the behaviors of dam and foundation correspond with the designed patterns in the construction period and the initial operation period.

关键词： Super-high arch dam Foundation surface optimization design Stability analysis

optimization design of spar cap layup for wind turbine blade

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Frontiers of Structural and Civil Engineering 2012年第1期6卷 53-56页

作者： Jie ZHU Xin CAI Pan PAN Rongrong GU College of Mechanics and Materials Hohai UniversityNanjing 210098China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China

Based on the aerodynamic shape and structural form of the blade are fixed,a mathematical model of optimization design for wind turbine blade is established.The model is pursued with respect to minimum the blade mass to reduce the cost of wind turbine production.The material layup numbers of the spar cap are chosen as the design variables;while the demands of strength,stiffness and stability of the blade are employed as the constraint conditions.The optimization design for a 1.5 MW wind turbine blade is carried out by combing above objective and constraint conditions at the action of ultimate flapwise loads with the finite element software ANSYS.Compared with the original design,the optimization design result achieves a reduction of 7.2%of the blade mass,the stress and strain distribution of the blade is more reasonable,and there is no occurrence of resonance,therefore its effectiveness is verified.

关键词： wind turbine blade spar cap layup optimization design blade mass

Towards an optimization design of seepage control：A case study in dam engineering

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Science China(Technological Sciences) 2017年第12期60卷 1903-1916页

作者： LI Xing CHEN YiFeng HU Ran YANG ZhiBing State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China

High dams generally suffer from higher seepage risks in their foundations, and seepage control is an important technology for limiting the amount of leakage and improving the stability of the foundations. In this study, a procedure was proposed for optimization design of seepage control system in large-scale hydropower projects, which relies on sufficient characterization of site conditions and proper quantification of the performance of the seepage control system. The proposed procedure was applied to the design of seepage control system in the Mengdigou Hydropower Station consisting of a double-curvature arch dam201 m in height. An optimized layout of the seepage control system, including the extended length of grout curtain, the rows of grouting holes and the spacing of drainage holes, was suggested. The proposed procedure provides a guide with lower risk and higher confidence for performance assessment and optimization design of seepage control systems in high dam engineering.

关键词： rock foundation seepage control grout curtain drainage system optimization design

Hybrid uncertainties-based analysis and optimization design of powertrain mounting systems

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Science China(Technological Sciences) 2020年第5期63卷 838-850页

作者： CAI BoHao SHANGGUAN Wen-Bin LÜHui BO Tao School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou 510641China

In this study,a hybrid uncertainties-based analysis and optimization method is presented for the designs of the powertrain mounting system(PMS)involving mixed uncertainties.In the presented method,the PMS parameters with sufficient data are treated as random variables,while those with limited information are defined as interval variables.Then,an uncertainty-based analysis method called as hybrid interval-random perturbation-central difference method(HIRP-CDM),is proposed to compute the hybrid interval-random outputs of the inherent characteristics of the PMS in concerned directions.In addition,the hybrid interval-random-Monte Carlo method(HIR-MCM)is developed to verify the computational accuracy of HIRP-CDM.Next,an optimization model mixed uncertainties is built up for the PMS design based on HIRP-CDM,in which the hybrid intervalrandom outputs of the concerned inherent characteristics are adopted to construct the design objective and constrains.The complex optimization problem can be effectively settled by means of HIRP-CDM.The effectiveness of the presented method is verified by a numerical example.

关键词： powertrain mounting system hybrid uncertainties uncertainty analysis optimization design

Comprehensive optimization design of aerodynamic and electromagnetic scattering characteristics of serpentine nozzle

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Chinese Journal of Aeronautics 2021年第3期34卷 118-128页

作者： Yubo HE Qingzhen YANG Xiang GAO School of Power and Energy Northwestern Polytechnical UniversityXi’an 710129China

Comprehensive optimization design of serpentine nozzle with trapezoidal outlet was studied to improve its aerodynamic and electromagnetic scattering performance.Serpentine nozzles with different center offsets and different ratios of the bases of the trapezoidal outlet were generated based on curvature control regulation.Computational Fluid Dynamics(CFD)simulations have been conducted to obtain the flow field in the nozzle,and Forward-Backward Iterative Physical Optics(FBIPO)method was applied to study the electromagnetic scattering characteristics of the nozzle.Guarantee Convergence Particle Swarm optimization(GCPSO)algorithm based on Radial Basis Function(RBF)neural network was used to optimize the geometry of the nozzle in consideration of its aerodynamic and electromagnetic scattering characteristics.The results show that the GCPSO method based on RBF can be used to optimize the aerodynamic characteristics of the internal flow and the scattering characteristics of the cavity of the serpentine nozzle with irregular outlet.The optimized model has a higher center offset and a lower ratio of the bases of the trapezoidal outlet after optimization compared to the original model.The optimized model leads to a slight change in aerodynamic performance,with a total pressure recovery coefficient increase of 0.31%and a discharge coefficient increase of 0.41%.In addition,the Radar Cross Section(RCS)decreases also by around 83.33%and the overall performance is significantly improved,with a decrease of the optimized objective function by around 38.74%.

关键词： Forward-Backward Iterative Physical Optics(FBIPO) Guarantee Convergence Particle Swarm optimization(GCPSO) Nozzle design optimization design Radar Cross Section(RCS) Serpentine nozzle

Uncertainty-based Multidisciplinary design optimization using An Approximated Second-Order Reliability Analysis Strategy

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Mechanical Engineering Science 2022年第1期4卷 1-5页

作者： Zhiyuan LYU Hongtao WANG Hengfei YANG Jiapeng WANG Ketema Mikiyas Solomon Debiao MENG School of Mechanical and Electrical Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Institute of Electronic and Information Engineering of UESTC in Guangdong Dongguan 523808China Yangzhou Yangjie Electronic Technology Co. Ltd.Jiangsu Yangzhou 225008China

In uncertainty-based multidisciplinary design optimization(UBMDO),all reliability limitation factors are maintained due to minimize the cost target function.There are many reliability evaluation methods for reliability limitation factors.The second-order reliability method(SORM)is a powerful most possible point(MPP)-based method.It can provide an accurate estimation of the failure probability of a highly nonlinear limit state function despite its large curvature.But the Hessian calculation is necessary in SORM,which results in a heavy computational cost.Recently,an efficient approximated second-order reliability method(ASORM)is proposed.The ASORM uses a quasi-Newton method to close to Hessian without the direct calculation of Hessian.To further improve the UBMDO efficiency,we also introduce the performance measure approach(PMA)and the sequential optimization and reliability assessment(SORA)strategy.To solve the optimization design problem of a turbine blade,the formula of MDO with ASORM under the SORA framework(MDO-ASORM-SORA)is proposed.

关键词： uncertainty reliability analysis optimization design turbine blade