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Study on the control mechanism of China aerospace enterprises' binary multinational operation

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Journal of Systems Engineering and Electronics 2008年第5期19卷 952-958页

作者： Wang Jian li Hanling Wu weiwei School of Management Harbin Inst. of Technology Harbin 150001 P. R. China

China＇s aerospace enterprises carry on the multinational operation and participate in the international competition and the international division of labor and cooperation positively. This article first analyzs China aerospace enterprises＇ binary multinational business control objective and constructes its model. Then the article analyzes the tangible and intangible control mechanism of China aerospace enterprises＇ binary multinational operation respectively. Finally, the article constructs the model of China aerospace enterprises＇ binary multinational operation mechanisms.

关键词： aerospace enterprise multinational operation binary operation control mode.

Crushing Behaviors of Frac tai Hexagonal Tubular Structures: Experiments and Plastic Analysis

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Acta Mechanica Solida Sinica 2019年第6期32卷 713-724页

作者： weiwei li Bei Zhang Hualin Fan Research Center of lightweight Structures and Intelligent Manufacturing State Key Laboratory of Mechanics and Control of Mechanical StructuresNanjing University of Aeronautics and AstronauticsNanjing 210016China State Key Laboratory for Disaster Prevention&Mitigation of Explosion&Impact PLA Army Engineering UniversityNanjing 210007China Department of Civil Engineering Nanyang Institute of TechnologyNanyang 473004China Research Institute for National Defense Engineering of Academy of Military Science PLA Luoyang 471023China

Fractal tubular structures(FTSs)can greatly increase the anti-crushing and energy absorption capacity of the *** reveal this mechanism,fractal hexagonal tubes(FHTs)with self-similar fractal structure were designed and *** experiments were carried out to verify the crushing modes of structures with different scale *** with the single-cell structure,FHTs have much greater mean crushing force(MCF).According to the experiments and the numerical simulations,when the side length of the second-order hexagon is 0.3 times of the length of the first-order primary hexagon,the FTS has the greatest peak force(PF)and MCF as well as the most excellent energy-absorbing *** folding styles were revealed by the experiments and the numerical simulation when changing the scale factor,including the overall folding mode,the local foaling mode and the hybrid folding *** plastic models were built,which consistently predicted the MCF.

关键词： Fractal structure Crushing Energy absorption Plastic analysis

Study on Adjoint-Based Optimization Method For Multi-Stage Turbomachinery

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Journal of Thermal Science 2011年第5期20卷 398-405页

作者： weiwei li Yong Tian Weilin Yi Lucheng Ji weiwei Shao Yunhan Xiao School of Aerospace Engineering Beijing Institute of Technology Beijing 100081 China Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100190 China Graduate School of Chinese Academy of Sciences Beijing 100190 China

Adjoint-based optimization method is a hotspot in ***,this paper presents principles of adjoint method from Lagrange multiplier ***,combining a continuous route with thin layer RANS equations,we formulate adjoint equations and anti-physical boundary *** to the multi-stage environment in turbomachinery,an adjoint interrow mixing method is *** techniques of solving flow equations and adjoint equations are almost the same,and once they are converged respectively,the gradients of an objective function to design variables can be calculated using complex method ***,integrating a shape perturbation parameterization and a simple steepest descent method,a frame of adjoint-based aerodynamic shape optimization for multi-stage turbomachinery is *** last,an inverse design of an annular cascade is employed to validate the above approach,and adjoint field of an Aachen 1.5 stage turbine demonstrates the conservation and areflexia of the adjoint interrow mixing *** a direct redesign of a 1+1 counter-rotating turbine aiming to increase efficiency and apply constraints to mass flow rate and pressure ratio is taken.

关键词： adjoint method aerodynamic shape optimization multi-stage turbomachinery N-S equations

An aerodynamic design and numerical investigation of transonic centrifugal compressor stage

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Journal of Thermal Science 2011年第3期20卷 211-217页

作者： Weilin Yi Lucheng Ji Yong Tian weiwei Shao weiwei li Yunhan Xiao School of Aerospace Engineering Beijing Institute of Technology Beijing 100081 China Research Center thr Energy and Power Chinese Academy of Sciences Beijing 100190 China

In the present paper,the design of a transonic centrifugal compressor stage with the inlet relative Mach number about 1.3 and detailed flow field investigation by three-dimensional CFD are *** the CFD program was validated by an experimental *** the preliminary aerodynamic design of stage completed through in-house one-dimensional *** types of impellers and two sets of stages were computed and *** can be found that the swept shape of leading edge has prominent influence on the performance and can enlarge the flow ***,the performance of the stage with swept impeller is better than *** total pressure ratio and adiabatic efficiency of final geometry achieve 7:1 and 80% *** vane diffuser with same airfoils along span increases attack angle at higher span,and the local flow structure and performance is deteriorated.

关键词： Impeller Diffuser CFD Aerodynamic Design

Aerodynamic adjoint optimization of turbomachinery with direct control on blade design parameters

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Chinese Journal of Aeronautics 2023年第11期36卷 119-134页

作者： Xin li Tongtong MENG weiwei li ling ZHOU Lucheng JI Institute for Aero Engine Tsinghua UniversityBeijing 100084China School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

Nowadays,the adjoint method has become a popular approach in the optimization of turbomachinery to further improve its aerodynamic ***,design variables in these adjoint optimization applications are generally not direct design parameters of blade(such as wedge angles or maximum thickness),making the geometric variation by adjoint optimization can hardly be re-extracted as the change of each design *** giving considerations to the G1 continuity constraint of adjoint method on its parameterization method,this manuscript shows how to apply a parameterization method in 3D blade design process into adjoint *** all design parameters can therefore be treated as design variables in the adjoint method and then participate in the sensitivity-based ***,a fitted Rotor 67 blade is optimized and the adiabatic efficiency is significantly improved by nearly 0.91%.

关键词： Adjoint method Parameterization method Aerodynamic optimization Customized blading method Compressor Turbomachinery

Integrated passage design based on extended free-form deformation and adjoint optimization

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Chinese Journal of Aeronautics 2023年第4期36卷 148-164页

Inspired by the three-dimensional design of flow passages in turbomachinery,this study proposes the concept of integrated passage *** capability of adjoint method for efficient optimization and the flexibility of the parameterization method based on extended free-form defor-mation have been considered to develop a feasible approach to design an integrated *** concept was applied to redesign a typical transonic fan,Rotor 67,and the results were analyzed by *** is shown that the passage was adequately adjusted in all three dimensions and reduced the strength of shock wave and wake-induced *** particular,the secondary flow was appropriately reorganized and the corner separation was well controlled in the end wall region,leading to signif-icant improvements in adiabatic efficiency and diffusion.

关键词： Turbomachinery Aerodynamic Transonic flow Integrated passage design Extended free-form defor-mation Adjoint optimization

Crashworthiness Design and Multi-Objective Optimization for Bio-Inspired Hierarchical Thin-Walled Structures

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Computer Modeling in Engineering & Sciences 2022年第5期131卷 929-947页

作者： Shaoqiang Xu weiwei li lin li Tao li Chicheng Ma School of Transportation and Vehicle Engineering Shandong University of TechnologyZibo255049China School of Mathematics and Statistics Shandong University of TechnologyZibo255049China

Thin-walled structures have been used in many fields due to their superior mechanical *** this paper,two types of hierarchical multi-cell tubes,inspired by the self-similarity of Pinus sylvestris,are proposed to enhance structural energy absorption *** finite element models of the hierarchical structures are established to validate the crashworthiness performance under axial dynamic *** theoreticalmodel of themean crushing force is also derived based on the simplified super folded element *** finite element results demonstrate that the energy absorption characteristics and deformation mode of the bionic hierarchical thin-walled tubes are further improved with the increase of hierarchical *** can be also obtained that the energy absorption performance of corner self-similar tubes is better than edge self-similar ***,multiobjective optimization of the hierarchical tubes is constructed by employing the response surface method and genetic algorithm,and the corresponding Pareto front diagram is *** research provides a new idea for the crashworthiness design of thin-walled structures.

关键词： Bionic structure crashworthiness design hierarchical tube multi-objective optimization

Quasi-One-Dimensional van der Waals Transition Metal Trichalcogenides

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Research 2023年第4期2023卷 219-243页

作者： Mengdi Chen Lei li Manzhang Xu weiwei li Lu Zheng Xuewen Wang Frontiers Science Center for Flexible Electronics(FSCFE)&Shaanxi Institute of Flexible Electronics(SIFE) Northwestern Polytechnical University(NPU)127 West Youyi RoadXi'an 710072China Shaanxi Key Laboratory of Flexible Electronics(KLoFE) Northwestern Polytechnical University(NPU)127 West Youyi RoadXi'an 710072China MIIT Key Laboratory of Flexible Electronics(KLoFE) Northwestern Polytechnical University(NPU)127 West Youyi RoadXi’an710072China Key Laboratory of Flexible Electronics of Zhejiang Provience Ningbo Institute of Northwestern Polytechnical University218 Qingyi RoadNingbo 315103China.

The transition metal trichalcogenides(TMTCs)are quasi-one-dimensional(1D)MX_(3)-type van der Waals layered semiconductors,where M is a transition metal element of groups IV and V,and X indicates chalcogen *** to the unique quasi-1D crystalline structures,they possess several novel electrical properties such as variable bandgaps,charge density waves,and superconductivity,and highly anisotropic optical,thermoelectric,and magnetic *** study of TMTCs plays an essential role in the 1D quantum materials field,enabling new opportunities in the material research ***,tremendous progress in both materials and solid-state devices has been made,demonstrating promising applications in the realization of nanoelectronic *** review provides a comprehensive overview to survey the state of the art in materials,devices,and applications based on ***,the symbolic structure,current primary synthesis methods,and physical properties of TMTCs have been ***,examples of TMTC applications in various fields are presented,such as photodetectors,energy storage devices,catalysts,and ***,we give an overview of the opportunities and future perspectives for the research of TMTCs,as well as the challenges in both basic research and practical applications.

关键词： Transition realization crystalline

Deformation mode and energy absorption of polycrystal-inspired square-cell lattice structures

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Applied Mathematics and Mechanics(English Edition) 2020年第10期41卷 1561-1582页

作者： Yijie BIAN Puhao li Fan YANG Peng WANG weiwei li Hualin FAN School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092China Research Center of lightweight Structures and Intelligent Manufacturing State Key Laboratory of Mechanics and Control of Mechanical StructuresNanjing University of Aeronautics and AstronauticsNanjing 210016China

Lattice structures are widely used in many engineering fields due to their excellent mechanical properties such as high specific strength and high specific energy absorption(SEA)*** this paper,square-cell lattice structures with different lattice orientations are investigated in terms of the deformation modes and the energy absorption(EA)*** element(FE)simulations of in-plane compression are carried out,and the theoretical models from the energy balance principle are developed for calculating the EA of these lattice *** agreement is achieved between the FE simulation results and the theoretical *** indicates that the 30◦oriented lattice has the largest EA ***,inspired by the polycrystal microstructure of metals,novel structures of bi-crystal lattices and quad-crystal lattices are developed through combining multiple singly oriented lattices *** results of FE simulations of compression indicate that the EA performances of symmetric lattice bi-crystals and quad-crystals are better than those of the identical lattice polycrystal *** work confirms the feasibility of designing superior energy absorbers with architected meso-structures from the inspiration of metallurgical concepts and microstructures.

关键词： lattice structure quasi-static loading deformation mode energy absorption(EA)