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A novel robust aerodynamic optimization technique coupled with adjoint solvers and polynomial chaos expansion

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Chinese Journal of Aeronautics 2022年第10期35卷 35-55页

作者： Wei ZHANG qiang WANG Fanzhi ZENG Chao yan National Key Laboratory of Computational Fluid Dynamics Beihang UniversityBeijing 100083China Aerospace Times Feipeng Company Limited China Academy of Aerospace Electronics TechnologyKunshan 215000China China Academy of Aerospace Aerodynamics Beijing 100074China

Uncertainty is common in the life cycle of an aircraft, and Robust Aerodynamic Optimization(RAO) that considers uncertainty is important in aircraft design. To avoid the curse of dimensionality in surrogate-based optimization, this study proposes an adjoint RAO technique called “R-Opt”. Polynomial Chaos Expansion(PCE) is coupled with the R-Opt technique to quantify uncertainty in the responses of the target(including its mean and standard deviation). Only one process of PCE model construction is required in each iteration, and the gradients of uncertainty can be inferred via chain rules. The proposed method is more efficient than prevalent methods,and avoids the problem of a disagreement over the best PCE basis from among a number of PCE models(especially in case of sparse PCE). It also supports the application of sparse *** benchmark tests and two airfoil cases were used to verify R-Opt, and the optimal solutions were deemed to be robust. It improved the mean aerodynamic performance and reduced the standard deviation of the target.

关键词： Adjoint technique Polynomial chaos expansion Robust design Uncertainty analysis Uncertainty gradient propagation

Modulation of driving signals in flow control over an airfoil with synthetic jet

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Chinese Journal of Aeronautics 2020年第12期33卷 3138-3148页

作者： Zhiyong LIU Zhenbing LUO qiang LIU yan ZHOU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China China Aerodynamics Research and Development Center Mianyang 621000China

A new skill of modulating driving signals of a synthetic jet with low frequency is introduced to enhance the control *** on dynamic mesh technique,the effect of flow control over a NACA0015 airfoil with a Synthetic Jet Actuator(SJA)has been *** SJA is located at x/c=10%,and two jet injection angles of 90°and 30°have been *** structures indicate that modulation with low frequency can reduce the dissipation rate of vortices after they shed off the *** aerodynamic performance of the airfoil could be *** the injection angle of 90°,modulation can increase the control authority of the *** to the unmodulated case,increment of lift-to-drag ratio is up to 15%.The modulating frequency corresponding to the largest increment is F_(M)^(+)≈*** the injection angle of 30°,improvement of aerodynamic forces positively relates to momentum coefficient of the *** to the decrease of effective momentum,modulation degrades the effect of flow *** opposite responses to modulation are believed to have a relationship with the variation of primary control *** jet injection angle varies from 90°to 30°,the primary mechanism changes from the interaction of vortices and waves to the direct momentum *** skill of modulation of driving signals is very useful for applications of SJA.

关键词： Airfoil Flow control Injection angle Modulation Momentum coefficient Synthetic jet

Simulation on Evaporation and Motion of Atomized Droplets in Spray Dry Flue Gas Desulfurization Tower

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Journal of Thermal Science 2022年第6期31卷 2252-2263页

作者： ZHANG Tengfei TANG qiang PU Chao yan Yunfei Key Laboratory of Low-grade Energy Utilization Technologies and Systems Ministry of EducationChongqing UniversityChongqing400044China

The evaporation and motion of atomized droplets have an essential effect on the safe and efficient long-term operation of the desulphurization tower. Therefore, the two-phase flow model is established and solved by three-dimensional steady Reynolds-averaged Navier-Stokes equations;the droplets are tracked by Eulerian-Lagrangian method. The three factors, including inlet swirling flow of flue gas, initial droplet diameter, and inlet flue gas temperature, are analyzed to show the effects on the evaporation and motion of atomized droplets, respectively. The results show that the swirling flow of flue gas and initial droplet diameter dominate the penetration length of the atomized droplets and the mixing characteristic of droplets and flue gas. With the increase of droplet diameter, the length of droplet penetrating flue gas increases. When droplet diameter is 200 μm and inlet swirl number is 0.35, droplets completely penetrate the core area. Therefore, this is the maximum initial droplet diameter at the inlet swirl number of 0.35. The droplets evaporation time of initial 150 μm diameter is 85.5% longer than that of 50 μm droplets(0.35 of inlet swirl number). Increasing the inlet flue gas temperature can enhance the heat transfer. When inlet flue gas temperature rises from 483 K to 523 K, the evaporation time decreases by 33.8%. The results can be used to guide the optimization of droplets spray evaporation under practical operating conditions in the desulfurization tower.

关键词： spray dry FGD atomized droplets swirling flow penetration length droplet evaporation

Anti-corrosive and highly reversible zinc metal anode enabled by the phenolic resin coating

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Rare Metals 2024年第5期43卷 2115-2124页

作者： ya-Ping Wang ya-Di yang Shu-Qi Duan Li Wang Jia-Shuo Guo An-qiang Pan School of Materials Science and Engineering Hebei University of TechnologyTianjin 300130China Key Laboratory of Special Functional Materials for Ecological Environment and Information(Hebei University of Technology).Ministry of Education Tianjin 300130China Key Laboratory for New Type of Functional Materials in Hebei Province Hebei University of TechnologyTianjin 300130China School of Materials Science and Engineering Central South UniversityChangsha 410083China

Aqueous zinc-ion batteries have attracted much attention due to their high theoretical capacity,low cost high safety,and ***,challenges such as dendrite growth and side reactions severely hinder the electrochemical performance of the Zn anode,leading to low Coulombic efficiency(CE)or even short circuits Herein,phenolic resin(PF)is used as a protective coating on the surface of the zinc metal *** PF layer can greatly improve the corrosion resistance of the Zn electrode in the ***,this artificial electrode/electrolyte interphase also elevates the nucleation barrier and restrains Zn^(2+)2D diffusion,regulating the zinc deposition/dissolution *** a result,PF@Zn symmetric cells exhibit superior performance than that of bare Zn symmetric cells,achieving a stable and dendrite-free cycle of 1400 ***,the carbon nanotube MnO_(2)||PF@Zn(CNT/MnO_(2)||PF@Zn)full cell also delivers a long cycle life with a high-capacity retention of about 180.0 m Ah·g^(-1)after 1400 cycles,far exceeding that of bare Zn *** work provides a facile strategy for achieving a dendrite-free and rechargeable zinc anode.

关键词： Rechargeable aqueous batteries Zn metal anode Phenolic resin Anti-corrosion

New Compacton-Like and Solitary Pattern-Like Solutions of （2＋1）-Dimensional Generalization of Modified KdV Equation

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Communications in Theoretical Physics 2005年第5X期44卷 789-792页

作者： CHEN Yong yan Zhen-ya Nonlinear Science Center and Department of Mathematics Ningbo University Ningbo 315211 China Key Laboratory of Mathematics Mechanization Institute of System Science Academy of Mathematics and System Sciences the Chinese Academy of Sciences Beijing 100080 China

Recently some (1+1)-dimensional nonlinear wave equations with linearly dispersive terms were shown to possess compacton-like and solitary pattern-like solutions. In this paper, with the aid of Maple, new solutions of (2+1)-dimensional generalization of mKd V equation, which is of only linearly dispersive terms, are investigated using three new transformations. As a consequence, it is shown that this (2+ 1)-dimensional equation also possesses new compacton-like solutions and solitary pattern-like solutions.

关键词： (2+1)-dimensional nonlinear wave equation comptacton-like solution solitary pattern-like solution

Chaos Control in a New Three-Dimensional Chaotic T System

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Communications in Theoretical Physics 2008年第4期49卷 951-954页

作者： CHEN Yong yan Zhen-ya Shanghai Key Laboratory of Trustworthy Computing East China Normal University Shanghai 200062 China Key Laboratory of Mathematics Mechanization Institute of Systems Science AMSS Chinese Academy of Sciences Beijing 100080 China International Centre for Materials Physics the Chinese Academy of Sciences Shenyang 110016 China

In this paper, we study chaos control of the new 3D chaotic system. We use three feedback methods （the linear, speed, doubly-periodic function controller） to suppress the chaos to unstable equilibrium. As a result, some controllers are obtained. Moreover, numerical simulations are used to verify the effectiveness of the obtained controllers.

关键词： chaos control chaotic T system feedback control Routh-Hurwitz theorem numerical simulation

Wettability between titanium-containing steels and TiN ceramic substrate

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Journal of Iron and Steel Research International 2023年第4期30卷 677-686页

作者： ya-cen Deng Hao Liu Min Zhang Xu-bin Zhang qiang-qiang Wang Sheng-ping He College of Materials Science and Engineering Chongqing Key Laboratory of Vanadium–Titanium Metallurgy and Advanced MaterialsChongqing UniversityChongqing 400044China Institute of Material Engineering and Technology Pangang Group Research Institute Co.Ltd.Panzhihua 617000SichuanChina

The wettability between TiN ceramic substrates and steels with various Ti contents was studied under an argon atmosphere at 1550℃ using a modified sessile drop *** electron probe microanalyzer and thermodynamic calculations were applied to investigate the interface between the steels and the TiN substrates as well as the surface of solidified steel *** measured apparent contact angles between the TiN substrates and steels were 96°,91°,and 146°,as the Ti content in the steel samples was 0.01,0.31,and 0.68 wt.%,*** reaction products were found at the interface,and only physical interactions *** wettability between high titanium steels(0.68 wt.%Ti)and TiN ceramic substrates should be evaluated from various perspectives,as many TiN particles existing in steel made the apparent contact angle increased significantly,deviating from the true value of contact angle.

关键词： Wettability Contact angle High-Ti steel TiN ceramic

Investigations on vortex structures for undulating fin propulsion using phase-locked digital particle image velocimetry

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Journal of Hydrodynamics 2021年第3期33卷 572-582页

作者： ya-qiang Bai Jun Zhang Shu-cheng Zhai Guo-ping Zhang China Ship Scientific Research Center Wuxi214082China National Key Laboratory on Ship Vibration and Noise Wuxi214082China

The Gymnarchus niloticus fish can swim in surging and heaving directions only with a long undulating ribbon fin while keeping its body along almost straight *** features substantially inspire the design of underwater vessels with high maneuverability and station keeping performance,which is characterized by peculiar vortex structures induced by undulating fin *** reveal the propulsion mechanism under the evolution of these complex vortex structures,the variation of velocity field with the undulating fin’s wave phase on cross section and mid-sagittal plane at wave amplitude of 85°is investigated by phase-locked digital particle image velocimetry(DPIV).Through experimental flow field images,two typical vortex structures are clearly identified,i.e.,streamwise vortex and crescent vortex,which is further explained by supplemental numerical simulations using large eddy *** characteristic and its evolution on cross sections and mid-sagittal planes is investigated,and its relationship with thrust,heave force is also *** is found that the two kinds of vortexes induce the main hydrodynamic forces in two directions synchronously,which brings the undulating fin propulsion an extra-ordinal *** research will be useful for understanding the potential mechanism of this novel propulsion and is of great application prospect in designing more maneuverable underwater vehicles.

关键词： Undulating fin propulsion vortex structure phase-locked digital particle image velocimetry(DPIV) hydrodynamic mechanism

Design and realization of phase retardation-control polarization controllers based on artificial birefringence

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The Journal of China Universities of Posts and Telecommunications 2011年第6期18卷 116-121页

作者： LIAO yan-na YIN ya-fang School of Electronic Engineering Xi＇an University of Posts and Telecommunications Xi＇an 710121 China

Polarization controllers （PCs） are indispensable passive components for state of polarization （SOP） control in optical fiber communication systems. In order to overcome the disadvantages of existing polarization controller （PC）, a novel PC based on the artificial birefringence is designed in this paper. The PC results from the concatenation of 3 phase retardation control units each of which consists of two polarization beam splitters, two prisms and one piezoz-lectric transducer （PZT） piezoelectric ceramic. The experimental results show that the proposed PC can convert an arbitrary input SOP to any expected output one with high accuracy under low control voltage.

关键词： PC artificial birefringence piezoelectric ceramic component