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Gust load alleviation wind tunnel tests of a large-aspect-ratio flexible wing with piezoelectric control

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Chinese Journal of Aeronautics 2017年第1期30卷 292-309页

作者： Bi Ying Xie Changchuan An chao Yang chao School of Aeronautic Science and Engineering Beihang University

An active control technique utilizing piezoelectric actuators to alleviate gust-response loads of a large-aspect-ratio flexible wing is investigated. Piezoelectric materials have been extensively used for active vibration control of engineering structures. In this paper, piezoelectric materials further attempt to suppress the vibration of the aeroelastic wing caused by gust. The motion equation of the flexible wing with piezoelectric patches is obtained by Hamilton＇s principle with the modal approach, and then numerical gust responses are analyzed, based on which a gust load alleviation（GLA） control system is proposed. The gust load alleviation system employs classic propor tional-integral-derivative（PID） controllers which treat piezoelectric patches as control actuators and acceleration as the feedback signal. By a numerical method, the control mechanism that piezoelectric actuators can be used to alleviate gust-response loads is also analyzed qualitatively. Furthermore, through low-speed wind tunnel tests, the effectiveness of the gust load alleviation active control technology is validated. The test results agree well with the numerical results. Test results show that at a certain frequency range, the control scheme can effectively alleviate the z and x wingtip accelerations and the root bending moment of the wing to a certain extent. The control system gives satisfying gust load alleviation efficacy with the reduction rate being generally over 20%.

关键词： Active control Aeroelastic wing Gust load alleviation Gust response Piezoelectric actuators Wind tunnel test

Jet dispersion and deposition of charged particles in confined chambers

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Particuology 2010年第1期8卷 28-36页

作者： chao Zhu Dawei Wang chao-Hsin Lin Department of Mechanical Engineering NewJersey Institute of Technology Newark NJ 07102 USA Environmental Control Systems Boeing Commercial Airplanes Seattle WA 98124 USA

Dispersion and surface deposition of charged particles by gas-solids jets in confined chambers are constantly encountered in many industrial applications such as in electrostatic precipitation and dry powder coating processes. Understanding and control of flow patterns and trajectories of charged particles are important to the optimal design and operation of such devices. In this study, modeling of flow fields and particle trajectories of dilute gas-solid two-phase flows with charged particles in confined chambers is performed. The dilute gas-solid two-phase flows are simulated by use of a hybrid Eulerian-Lagrangian approach with the one-way coupling between the gaseous phase and particle phase. The space charge distribution is included as a source term in equations of motion or Lagrangian equation of charged particles, which in turn depends on the particle trajectories that determine the space charge distribution. Our modeling predictions suggested that the electrostatic charge plays a significant role in particle radial dispersion. Effect of voltage has limited influence on particle trajectories however it can have a big impact on the residence time. Cone angle has a significant effect on the structure of flow field. For cone with a larger cone angle （typically over 15°）, there will be a flow separation along the side wall near the flow entrance region. By comparing with the conical chamber, the cylindrical chamber has a big vortex and three smaller vortexes in the lower part of the chamber, which would complicate the particle dispersion with or without the coupling of charging.

关键词： Charged particle deposition Confined chamber Electric field Jet dispersion

防隔水煤柱定向爆破应力转移机理及参数优化设计

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河南理工大学学报（自然科学版） 2025年第1期44卷 1-9页

作者：刘少伟郭泽政冯超牛帅河南理工大学能源科学与工程学院河南焦作454000 煤炭安全生产与清洁高效利用省部共建协同创新中心河南焦作454000 安阳工学院土木与建筑工程学院河南安阳455000

目的针对内部存在断层的防隔水煤柱在采动影响下应力场持续变化对其稳定性和工作面安全开采造成极大威胁的问题,方法以鹤壁中泰矿业有限公司3309工作面为工程地质背景,采用理论分析、正交试验和FLAC3D数值模拟试验,研究定向爆破应力转... 详细信息

目的针对内部存在断层的防隔水煤柱在采动影响下应力场持续变化对其稳定性和工作面安全开采造成极大威胁的问题,方法以鹤壁中泰矿业有限公司3309工作面为工程地质背景,采用理论分析、正交试验和FLAC3D数值模拟试验,研究定向爆破应力转移保护防隔水煤柱的影响因素以及不同切顶深度和切顶角度下防隔水煤柱内部应力分布特征。结果结果表明:随着切顶角度和切顶深度增加,垂直应力集中区逐渐向深部转移,但当切顶深度和切顶角度达到一定数值后,继续增加切顶角度或切顶深度对应力集中区位置及垂直应力峰值影响不再明显,对比不同方案防隔水煤柱内部测线数据可知,当切顶深度为15 m、切顶角度为15°时,应力集中区距回风巷距离最远,最远距离为19.76 m,应力峰值最小,最小值为15.65 MPa。结论采用定向爆破技术可以实现切顶卸压应力转移,能够阻断回风巷上覆岩层与防隔水煤柱周边岩层的联系,将防隔水煤柱靠近回风巷一侧应力向深部转移,以减少采动对防隔水煤柱的影响;现场工业性试验结果验证了选定方案切顶深度15 m、切顶角度15°的合理性,防隔水煤柱内部实现了应力转移,选定方案的成功应用有效提高了防隔水煤柱的稳定性,能够满足安全生产要求。研究结果可为类似地质条件下内部存在断层的防隔水煤柱的应力转移保护提供参考依据。

关键词：定向爆破应力转移断层数值模拟防隔水煤柱正交试验

Static aeroelastic analysis including geometric nonlinearities based on reduced order model

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Chinese Journal of Aeronautics 2017年第2期30卷 638-650页

作者： Xie Changchuan An chao Liu Yi Yang chao School of Aeronautic Science and Engineering Beihang University Beijing 100083 China

This paper describes a method proposed for modeling large deflection of aircraft in nonlinear aeroelastic analysis by developing reduced order model（ROM）.The method is applied for solving the static aeroelastic and static aeroelastic trim problems of flexible aircraft containing geometric nonlinearities;meanwhile,the non-planar effects of aerodynamics and follower force effect have been *** are computational inexpensive mathematical representations compared to traditional nonlinear finite element method（FEM） especially in aeroelastic *** approach for structure modeling presented here is on the basis of combined modal/finite element（MFE） method that characterizes the stiffness nonlinearities and we apply that structure modeling method as ROM to aeroelastic ***,the non-planar aerodynamic force is computed by the non-planar vortex lattice method（VLM）.Structure and aerodynamics can be coupled with the surface spline *** results show that both of the static aeroelastic analysis and trim analysis of aircraft based on structure ROM can achieve a good agreement compared to analysis based on the FEM and experimental result.

关键词： Aeroelasticity Finite element method Geometric nonlinearity Reduced order models Trims

Chih-chen Wang: the social responsibility of scientists

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National Science Review 2021年第4期8卷 195-200页

作者： chao Gu the Department of History of Science Technology and Medicine Peking University

Chih-chen Wang is a distinguished biochemist and molecular biologist, and an Academician of the Chinese Academy of Sciences (CAS).From 2008 to 2013, she was a vice chairperson of the National Committee of the Chinese People’s Political Consultative Conference(CPPCC). As a young researcher, Wang participated in research on insulin. Since the 1990s, she has been focusing on the study of protein folding, and has initiated a new research area of isomerase and molecular chaperones in China.

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Quantum simulation of τ-anti-pseudo-Hermitian two-level systems

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Chinese Physics B 2022年第10期31卷 182-188页

作者： chao Zheng Department of Physics College of ScienceNorth China University of TechnologyBeijing 100144China

Different from the Hermitian case, non-Hermitian(NH) systems have novel properties and strongly relate to open and dissipative quantum systems. In this work, we investigate how to simulate τ-anti-pseudo-Hermitian systems in a Hermitian quantum device using linear combinations of unitaries and duality quantum algorithm. Specifying the τ to time-reversal(T) and parity-time-reversal(PT) operators, we construct the two NH two-level systems, design quantum circuits including three qubits, and decide the quantum gates explicitly in detail. We also calculate the success probabilities of the *** implementation can be expected in small quantum simulator.

关键词： quantum simulation linear combination of unitaries non-Hermitian anti-pseudo-Hermitian

On the robustness of median sampling in noisy evolutionary optimization

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Science China(Information Sciences) 2021年第5期64卷 32-44页

作者： chao BIAN chao QIAN Yang YU Ke TANG State Key Laboratory for Novel Software Technology Nanjing University Shenzhen Key Laboratory of Computational Intelligence Department of Computer Science and EngineeringSouthern University of Science and Technology

Evolutionary algorithms(EAs) are a sort of nature-inspired metaheuristics, which have wide applications in various practical optimization problems. In these problems, objective evaluations are usually inaccurate, because noise is almost inevitable in real world, and it is a crucial issue to weaken the negative effect caused by noise. Sampling is a popular strategy, which evaluates the objective a couple of times, and employs the mean of these evaluation results as an estimate of the objective value. In this work, we introduce a novel sampling method, median sampling, into EAs, and illustrate its properties and usefulness theoretically by solving OneMax, the problem of maximizing the number of 1 s in a bit string. Instead of the mean, median sampling employs the median of the evaluation results as an estimate. Through rigorous theoretical analysis on OneMax under the commonly used onebit noise, we show that median sampling reduces the expected runtime exponentially. Next, through two special noise models, we show that when the 2-quantile of the noisy fitness increases with the true fitness, median sampling can be better than mean sampling; otherwise,it may fail and mean sampling can be better. The results may guide us to employ median sampling properly in practical applications.

关键词： evolutionary algorithms noisy optimization median sampling computational complexity runtime analysis

Divergent Pathways and Dynamic Effects of Intramolecular HydrideTransfer Reactions Mediated by Cp^*M(Ⅲ)Complexes(M=Co,Rh,lr)

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Chinese Journal of Chemistry 2020年第12期38卷 1579-1584页

作者： chao Zheng State Key Laboratory of Orgonometallic Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of Sciences345 Lingling LuShanghai 200032China

of main observation and conclusion Transition-metal-mediated hydride transfer reactions are fundamental steps in olefin polymerization and isomerization processes.P-Hydride elimination/migratory insertion sequence and ligand-to-ligand hydrogen transfer mechanism have been proposed for these *** have performed comprehensive theoretical studies on prototype 1,4-hydride transfer reactions mediated by the Cp^*M(Ⅲ)complexes(M=Co,Rh,Ir).Depending on the metal center,the reaction courses are quite divergent,ranging from dynamically concerted to explicitly stepwise manner.A More O'Farrell-Jencks-type plot is suggested to demonstrate the perturbation to the mechanistic continuum from the significant dynamic effects.

关键词： hydride steps perturbation

Variations of flutter mechanism of a span-morphing wing involving rigid-body motions

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Chinese Journal of Aeronautics 2018年第3期31卷 490-497页

作者： chao HUANG chao YANG Zhigang WU Changhong TANG School of Aeronautic Science and Engineering Beihang University The First Aircraft Institute Aviation Industry Corporation of China

The present paper aims to reveal the significance of rigid-body motions for the flutter mechanism of a span-morphing wing model. The inclusion of rigid-body motions into aeroelastic formulation and flutter analysis is presented. A state-space aeroelastic equation combining the dynamics of stepped Euler-Bernoulli beam with unsteady strip aerodynamic theory is developed by quasi-static modeling. Using a numerical example, variations of flutter mechanism from the bending-torsional flutter to the body-freedom flutter are observed as the span increases. In addition,effects of some dimensionless parameters on the variations of flutter mechanism are *** investigated parameters belonging to the fuselage have limited influences on the bendingtorsional flutter but a significant impact on the body-freedom flutter.

关键词： Aeroelasticity Aircraft design Body-freedom flutter Dynamic modeling Flutter Rigid body modes Span-morphing