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Dianwang Jishu/Power System Technology 2025年第1期49卷 306-315页

作者： Zhou, Yang Wang, Zhuding zhang, man Yang, Jie Shu, Dongsheng State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Shapingba District Chongqing 400044 China Chongqing Electric Energy Star Inc Jiulongpo District Chongqing 400039 China Economic Research Institute of State Grid Hubei Electric Power Company Hubei Province Wuhan 430000 China

Based upon the existing research findings of distribution network planning，and based on the optimization division of power areas (or grid cells), a heuristic method of distribution network planning, i.e., the grid cell based distribution network planning method, is proposed to adapt to the gradual increase in the penetration rate of distributed resources, wherein the power balancing method involves differential approaches of different space-time-resources and two typical operating modes. The optimization division of grid cells is carried out by the principles of nearby use for distributed power resources and "nearby backup supply", resulting in the regional grid cell, substation grid cell, medium-voltage and low-voltage grid cell in terms of space, and also the energy output type, energy input type and balance type in terms of resources. The real planning example shows that the proposed method has relatively strong operability. © 2025 Power System Technology Press. All rights reserved.

关键词： Power distribution planning

Large-eddy simulation and linear acoustic modeling of entropy mode oscillations in a model combustor with coolant injection

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Chinese Journal of Aeronautics 2018年第8期31卷 1691-1702页

作者： man zhang An LIANG AECC Commercial Aireraft Engine Co. LTD Shanghai 200241 China

Lean-burn combustor is particularly susceptible to combustion instability and the unsteady heat release is usually considered as the excitation of the self-maintained thermoacoustic oscillations. The transverse coolant injection is widely used to reduce the temperature of burnt gas, but on the other hand, it will introduce temperature fluctuation inside the ***, it is necessary to consider the influence of the coolant injection on combustion instability, and evaluate its dynamic feature. In this paper, Large-Eddy Simulation（LES） of the self-excited pressure oscillations in a model combustor with coolant injection is carried out. The analysis of transient flow characteristics and the identification of the pressure modes confirm that one of the low frequency pressure oscillations is related to entropy fluctuations, which is known as rumble combustion instability. The LES results show that transient coolant injection is another excitation of temperature fluctuation other than unsteady combustion. The amplitude of the entropy mode oscillation increases with increasing coolant air mass whereas the change of its frequency is insignificant. According to the major feature of entropy wave oscillation caused by coolant injection, a compact coolant injection model is proposed and applied in the One Dimensional（1 D） Acoustic Network Method（ANM）. Key correlations used in the model match well with LES data in low frequency range. This means that the coolant injection model is a complex one reflecting the interaction of the fluctuating coolant mass, pressure and temperature. Finally, the combustion instability frequencies and modes predicted by acoustic network method are also in good agreement with LES results.

关键词： Acoustic wave Combustion instabilityCoolant injection Entropy LES Network method Rumble Self-excited

Influence of the Acoustic Liner in Large Eddy Simulation of Longitudinal Thermoacoustic Instability in a Model Annular Combustor

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Journal of Thermal Science 2024年第2期33卷 710-724页

作者： MENG Sheng zhang man GAO Yi AECC Commercial Aircraft Engine Co. Ltd.Shanghai200241China School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai200240China

Although extensive efforts have been made to dampen the thermoacoustic instability,successfully controlling the pressure oscillations in modern gas turbines or aeroengines remains *** influence of the acoustic liner on the longitudinal thermoacoustic mode in a model annular combustor is investigated by Large Eddy Simulation(LES) in this *** result of the self-excited longitudinal thermoacoustic instability without the liner agrees well with the frequency and acoustic analysis of the pressure mode based on experimental *** different bias flow velocities of the liner located downstream of the combustor are then *** results reveal that the existence of the liner influences not only the acoustic field but also the flow *** the bias velocity is large,it leads to intense turbulence-induced fluctuations,and the pressure oscillation is modulated *** shows that the weak coupling between flow and pressure oscillations plays a significant role in the onset of the intermittency of a thermoacoustic *** on the dynamic analysis of the thermoacoustic system with the acoustic liner,this intermittency is caused by the influence of the flow field on the flame-acoustic ***,a low-order modeling method based on Van der Pol(VdP) oscillator with additive stochastic forcing is conducted to reproduce the evolving dynamics of the thermoacoustic *** the numerical cases demonstrated in this work are relatively simpler than those in a practical combustion system,the results are helpful for us to understand the effect of the acoustic liner and show the attractive potential to apply this device to suppress thermoacoustic instability.

关键词： thermoacoustic instability acoustic liner Large Eddy Simulation low-order modeling

Effect of mineral admixtures and repeated loading on chloride migration through concrete

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第9期11卷 683-690页

作者： Wu-man zhang Heng-jing BA School of Transportation Science and Engineering Beihang University Beijing 100191 China School of Civil Engineering Harbin Institute of Technology Harbin 150006 China

The effect of fly ash (FA) and ground granulated blast furnace slag (GGBFS) on chloride migration through concrete subjected to repeated loading was examined. Portland cement was replaced by three percentages (20%, 30%, and 40%) of mineral admixtures. Five repeated loadings were applied to concrete specimens using a WHY series fully automatic testing machine. The maximum loadings were 40% and 80% of the axial cylinder compressive strength (f′c). Chloride migration through concretes was evaluated using the rapid chloride migration test and the chloride concentration in the anode chamber was measured. The results showed that the replacement percentages of mineral admixtures, the curing time and repeated loading had a significant effect on chloride migration through concrete. The transport number of chloride through concrete cured for 28 d increased with increasing FA replacement and markedly decreased with extension of the curing time. 20% and 30% GGBFS replacement decreased the transport number of chloride through concrete, but 40% GGBFS replacement increased the transport number. Five repeated loadings at 40% or 80% f′c increased the transport number of chloride for all mixes.

关键词： Concrete Fly ash (FA) Ground granulated blast furnace slag (GGBFS) Chloride migration Repeated loading

Field estimation of maize plant height at jointing stage using an RGB-D camera

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The Crop Journal 2022年第5期10卷 1274-1283页

作者： Ruicheng Qiu man zhang Yong He College of Biosystem Engineering and Food Science Zhejiang UniversityHangzhou 310058ZhejiangChina Key Laboratory of Modern Precision Agriculture System Integration Research Ministry of EducationChina Agricultural UniversityBeijing 100083China

Plant height can be used for assessing plant vigor and predicting biomass and yield. manual measurement of plant height is time-consuming and labor-intensive. We describe a method for measuring maize plant height using an RGB-D camera that captures a color image and depth information of plants under field conditions. The color image was first processed to locate its central area using the S component in HSV color space and the Density-Based Spatial Clustering of Applications with Noise algorithm. Testing showed that the central areas of plants could be accurately located. The point cloud data were then clustered and the plant was extracted based on the located central area. The point cloud data were further processed to generate skeletons, whose end points were detected and used to extract the highest points of the central leaves. Finally, the height differences between the ground and the highest points of the central leaves were calculated to determine plant heights. The coefficients of determination for plant heights manually measured and estimated by the proposed approach were all greater than 0.95. The method can effectively extract the plant from overlapping leaves and estimate its plant height. The proposed method may facilitate maize height measurement and monitoring under field conditions.

关键词： Maize plant heigh Kinect Maize central area Point cloud data Image processing

On the comparison of particle regeneration technique and volume adaptive scheme in the compressible flow based on smoothed particle hydrodynamics

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Journal of Hydrodynamics 2022年第3期34卷 408-421页

作者： Ming-Kang Li Shuai zhang Yu-Xiang Peng A-man zhang College of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China Nanhai Institute of Harbin Engineering University Sanya572024China School of Marine Engineering and Technology Sun Yat-sen UniversityZhuhai519082China

The collapse of a cavitation bubble is an interesting topic and it has many applications in the engineering *** to its compressible nature,the modelling of a cavitation bubble is not easy by the Lagrangian method,like the smoothed particle hydrodynamics(SPH),as there is large variation of particle ***,there are two kinds of method that have been proposed to deal with this problem:the particle regeneration technique(PRT)and the volume adaptive scheme(VAS).They have all been validated via several numerical tests of compressible flow in the past *** is based on totally different concept,the ultimate simulation results and properties may ***,we intend to compare these two methods based on the Riemann-based SPH solver with monotone upwind-centered scheme for conservation laws(MUSCL)reconstruction via several numerical *** characteristics of these two methods are discussed and the applicable scope for them are also commented for further usage.

关键词： Compressible flow smoothed particle hydrodynamics(SPH) particle regeneration technique(PRT) volume adaptive scheme(VAS)

Experimental investigation of the interaction between a pulsating bubble and a rigid cylinder

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Acta Mechanica Sinica 2013年第4期29卷 503-512页

作者： A-man zhang Wei Xiao Shi-Ping Wang College of Shipbuilding Engineering Harbin Engineering University

In this paper, the behavior of a bubble near a rigid cylinder is studied experimentally as the positions of bubble induction change, and several cylinders with different diam- eters are used in the experiment. The main results are as follows. The behavior of a bubble near a rigid cylinder is distinct from that near a rigid plate. When the cylinders are laid in deep water, there will occur three kinds of typical bubble shapes as the distance between bubble and cylinder increases. And the bubble shapes are different as the diam- eter of cylinder varies. When the cylinders are laid near a free surface, the behaviors of bubble near cylinders with dif- ferent diameters are similar. For a certain distance between bubble and free surface, as the distance between bubble and cylinder increases, ＂double jet＂, ＂inclined jet＂ and ＂down- ward jet＂ will take place successively.

关键词： Bubble ~ Cylinder. Electric spark- Free sur-face ~ Jet

Coherent range-dependent map-drift algorithm for improving SAR motion compensation

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Journal of Systems Engineering and Electronics 2023年第1期34卷 47-55页

作者： zhang man WANG Guanyong WEI Feiming JIN Xue School of Electronic and Communication Engineering Guangzhou UniversityGuangzhou 510006China Beijing Institute of Radio Measurement Beijing 100854China School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200030China No.802 Research Institute of Shanghai Academy of Spaceflight Technology Shanghai 200050China Beijing Institute of Tracking and Communication Technology Beijing 100094China

Synthetic aperture radar(SAR) is usually sensitive to trajectory deviations that cause serious motion error in the recorded data. In this paper, a coherent range-dependent mapdrift(CRDMD) algorithm is developed to accommodate the range-variant motion errors. By utilizing the algorithm as an estimate core, robust motion compensation strategy is proposed for unmanned aerial vehicle(UAV) SAR imagery. CRDMD outperforms the conventional map-drift algorithms in both accuracy and efficiency. Real data experiments show that the proposed approach is appropriate for precise motion compensation for UAV SAR.

关键词： synthetic aperture radar(SAR) motion compensation(MOCO) coherent map-drift(CMD) range-variant

Removal of benzotriazole by heterogeneous photoelectro-Fenton like process using ZnFe_2O_4 nanoparticles as catalyst

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Journal of Environmental Sciences 2013年第4期25卷 801-807页

作者： Junfeng Wu Wenhong Pu Changzhu Yang man zhang Jingdong zhang School of Environmental Science and Engineering Huazhong University of Science and Technology School of Environmental and Municipal Engineering Henan University of Urban Construction School of Chemistry and Chemical Engineering Huazhong University of Science and Technology

ZnFe2O4 nanoparticles （ZFNPs） were developed as catalyst for the degradation of benzotriazole （BTA） by heterogeneous photoelectro- Fenton （PE-Fenton） like process. ZFNPs were prepared by a co-precipitation process and then characterized with transmission electron microscopy （TEM）, X-ray fluorescence （XRF）, X-ray diffraction （XRD） and BET surface area. Using such ZFNPs as catalyst, the degradation of BTA was investigated. Due to the high catalytic activity of ZFNPs, PE-Fenton like process showed efficient degradation of BTA. The influencing factors such as pH, dosage of ZFNPs, applied potential and initial concentration of BTA were systematically investigated. Under the optimum conditions, 91.2% of BTA was removed after 180 rain treatment.

关键词： ZnFe2O4 nanoparticles photoelectro-Fenton like process benzotriazole heterogeneous catalytic degradation

Numerical study on maldistribution of gas-solid flow in multiple-branching limestone-conveying pipelines of circulating fluidized bed

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Particuology 2019年第5期17卷 14-21页

作者： Shahong Zhu man zhang Juanli zhang Junfu Lyu Hairui Yang Key Laboratory for Thermal Science and Power Engineering of Ministry Education State Key Laboratory of Power Systems Department of Energy and Power Engineering. Tsinghua University. Beijing 100084 China

As one of the most important auxiliary systems of a circulating fluidized bed boiler,the limestone pneumatic conveying system is of great significance to its *** of powder in the different injecting ports seriously limits inner-furnace desulfurization performance owing to inefficient mixing of limestone powder and *** gas-solid flow characteristics of an industrial-scale multiple-branching limestone-conveying pipeline system of a 200 MW circulating fluidized bed boiler were studied using a computational particle fluid dynamics *** maldistribution intensity was studied under different operating conditions of air velocity and particle mass flow *** results indicated that when the air velocity increased,the maldistribution was mitigated,but when the particle mass flow rate increased,the maldistribution *** solve this problem,two improved schemes were proposed:adding a deflector at different angles and changing the height of pipeline *** to the simulation,the maldistribution could be efficiently mitigated using a distributor height in the range of 100-120 mm and a deflector angle of 10°-30°.

关键词： Circulating fluidized bed Limestone Pneumatic conveying Multiple-branching pipeline Maldistribution