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Experimental investigation and numerical analysis on high-efficiency shock vectoring control serpentine nozzles

CHINESE JOURNAL OF AERONAUTICS 2024年第12期37卷 296-324页

作者： hui, zhonghao Shi, Jingwei Lin, Wentao Zhou, Li Wang, Zhanxue Liu, Yongquan Northwestern Polytech Univ Sch Power & Energy Xian 710072 Peoples R China Natl Key Lab Sci & Technol Adv Light Duty Gas Turb Xian 710129 Peoples R China Collaborat Innovat Ctr Adv Aeroengine Beijing 100191 Peoples R China

The high-efficiency Shock Vectoring Control Serpentine Nozzle (SVCSN) takes into account both thrust vectoring and infrared stealth, and significantly improves the comprehensive performance of the aero-engines through an additional auxiliary duct. In this paper, the schlieren photographs at the exit of the high-efficiency SVCSN and the wall static pressure distributions were obtained by experiments, and the numerical results were used to enrich the thrust vectoring characteristics. The effects of the auxiliary injection were analyzed first to reveal the advantages of the high-efficiency SVCSN compared to the conventional SVCSN. Then, the aerodynamic parameters and the structural parameters of the high-efficiency SVCSN were investigated, including the Nozzle Pressure Ratio (NPR), the Secondary flow Pressure Ratio (SPR), the secondary flow relative area and the secondary flow injection angle. Finally, the coupling performance of the high-efficiency SVCSN is studied by using the approximate modeling technology. Results show that the auxiliary injection increases the range between the two shock legs of the "k" shock wave induced by the secondary flow, then causes the separation zone and high-pressure boss of the down wall to expand upstream, and finally results in a prominent increase in the thrust vectoring performance. The thrust vectoring angle and Vectoring Efficiency (VE) of the high-efficiency SVCSN are about 61.6% and 75.7%, respectively, higher than those of the conventional SVCSN at NPR = 6. The effects of the NPR and the SPR on the thrust vectoring performance of the high-efficiency SVCSN are coupled with each other. A larger NPR matched with a smaller SPR shows better thrust vectoring performance. The maximum fluctuations in thrust vectoring angle and VE caused by the NPR and SPRare about 22% and 64%. The VE decreases monotonously with the increase of the secondary flow relative area. Smaller secondary flow injection angle shows better thrust vector performan

关键词： Shock vectoring control Serpentine nozzle Auxiliary injection Thrust vectoring performance Flow control

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Enhancement of heat transfer of microcapsulated particles using copper particles and copper foam

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Particuology 2018年第6期16卷 85-93页

作者： zhonghao Rao Yiping Wen Chenzhen Liu School of Electrical and Power Engineering China University of Mining and TechnologyXuzhou 221116China

The application of phase-change materials (PCM)for thermal-energy storage is hampered by their low thermal *** particles (CP)and copper foam (CF)were used to enhance the thermal conductivity of a microencapsulated phase-change material (MicroPCM).The effects of the CP size and mass fraction and the pore number per inch (PPI)of the CF on the thermal properties of the MicroPCM were *** chemical and microstructures of the MicroPCM and its CP composites were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy,respectively. Their thermal conductivities,phase-change temperatures,and latent heats were *** CP into the MicroPCM decreased the latent heats with increasing *** thermal conductivities of MicroPCM/CP (Swt%,50nm diameter)and MicroPCM/CF (PPI 30)were 1.12times and 3.46times that of the unmodified MicroPCM at 20℃,***-energy storage performances of the MicroPCM/CF composites were studied at a power of 2.9±*** temperature of the contact surfaces of the pure MicroPCM and its composites (PPI 10,PPI 20,PPI 30)was 75.88,51.27,50.52,and 50.23℃,*** composites displayed more uniform temperature distributions.

关键词： Microencapsulated phase-change material Copper particles Copper foam Thermal conductivity Thermal energy storage

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Fast measurement and prediction method for electromagnetic susceptibility of receiver

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Journal of Systems Engineering and Electronics 2024年第2期35卷 275-285页

作者： CHEN Yan LU zhonghao LIU Yunxia State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System College of Electronic Science and TechnologyNational University of Defense TechnologyChangsha 410073China State Key Laboratory of Astronautic Dynamics Xi’an 710043China

Aiming at evaluating and predicting rapidly and accurately a high sensitivity receiver’s adaptability in complex electromagnetic environments,a novel testing and prediction method based on dual-channel multi-frequency is proposed to improve the traditional two-tone ***,two signal generators are used to generate signals at the radio frequency(RF)by frequency scanning,and then a rapid measurement at the intermediate frequency(IF)output port is carried out to obtain a huge amount of sample data for the subsequent ***,the IF output response data are modeled and analyzed to construct the linear and nonlinear response constraint equations in the frequency domain and prediction models in the power domain,which provide the theoretical criteria for interpreting and predicting electromagnetic susceptibility(EMS)of the *** experiment performed on a radar receiver confirms the reliability of the method proposed in this *** shows that the interference of each harmonic frequency and each order to the receiver can be identified and predicted with the sensitivity *** on this,fast and comprehensive evaluation and prediction of the receiver’s EMS in complex environment can be efficiently realized.

关键词： electromagnetic susceptibility(EMS) receiver dualchannel multi-frequency nonlinear response frequency domain power domain

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Enhancing lithium-sulfur battery performance with In_(2)O_(3)-In_(2)S_(3)@NSC heterostructures:Synergistic effects of double barrier and catalytic transformation

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Journal of Materials Science & Technology 2024年第2期169卷 105-114页

作者： Deqing He Chunyu Zhu Yutao Huo zhonghao Rao School of Energy and Environmental Engineering Hebei University of TechnologyTianjin 300401China Hebei Key Laboratory of Thermal Science and Energy Clean Utilization Hebei University of TechnologyTianjin 300401China School of Low-carbon Energy and Power Engineering China University of Mining and TechnologyXuzhou 221116China

The sluggish redox reaction kinetics of lithium polysulfides(LiPSs)are considered the main obstacle to the commercial application of lithium-sulfur(Li-S)*** accelerate the conversion by catalysis and inhibit the shuttling of soluble LiPSs in Li-S batteries,a solution is proposed in this *** solution involves fabrication of N,S co-doped carbon coated In_(2)O_(3)/In_(2)S_(3)heterostructure(In_(2)O_(3)-In_(2)S_(3)@NSC)as a multifunctional host material for the *** In_(2)O_(3)-In_(2)S_(3)@NSC composite can reduce the Gibbs free energy for the conversion reactions of LiPSs,which results in superior *** synergy between different components in In_(2)O_(3)-In_(2)S_(3)@NSC and the unique 3D structure facilitate ion and electron transport in Li-S *** In_(2)O_(3)-In_(2)S_(3)@NSC/Li 2 S 6 cathode exhibits excellent rate capacity,with a capacity of 599 mAh g−1 at 5.5 C,and good cycle stability,with a capacity of 436 mAh g^(−1)after 1000 cycles at 1 ***,this study proposes a promising solution to improve the energy storage properties of Li-S batteries,which could potentially facilitate the commercialization of Li-S batteries.

关键词： Li-S battery Multifunctional host material Synergy Heterostructures Energy storage properties

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Dark Solitary-Wave Solutions in Bulk Linear Media with Group Velocity Dispersion

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Chinese Physics Letters 1995年第7期12卷 396-399页

作者： LI zhonghao ZHOU Guosheng Department of Electronics and Information Science Shanxi UniversityTaiyuan 030006

A dark envelope solitary-wave solution in bulk dispersive linear media is obtained from the (3+1)-dimensional time-space coupled linear wave equation by taking account of the interplay between physical effects of transverse confinement and group velocity dispersion (GVD) effect under certain appropriate *** characteristics of the solution are discussed in both normal and anomalous GVD regions.

关键词： conditions. Dispersion wave

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Challenges in various thermal energy storage technologies

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Science Bulletin 2017年第4期62卷 231-233页

作者： Chenzhen Liu zhonghao Rao School of Electrical and Power Engineering China University of Mining and Technology Xuzhou 221116 China

With the worsening of energy shortage and environmental pollution,energy storage has received much attention in the fields of renewable and sustainable energy in recent *** is widely known that energy storage is a technique storing excess energy in one form and converting it back to the same form or another when necessary[1].Especially energy storage occupies an important position in solar energy,wind energy and ocean ***,energy storage methods include mechanical energy storage,

关键词：热能储存技术可再生能源环境污染能源短缺能源领域储能

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Green's function calculations of light nuclei

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Science China(Physics,Mechanics & Astronomy) 2016年第9期59卷 64-68页

作者： zhonghao Sun Qiang Wu FuRong Xu School of Physics Peking University

The influence of short-range correlations in nuclei was investigated with realistic nuclear force. The nucleon-nucleon interaction was renormalized with Vlowk technique and applied to the Green's function calculations. The Dyson equation was reformulated with algebraic diagrammatic constructions. We also analyzed the binding energy of 4He, calculated with chiral potential and CD-Bonn potential. The properties of Green's function with realistic nuclear forces are also discussed.

关键词： Green's function ab-initio calculations realistic nuclear forces

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Numerical study on solid–liquid phase change in paraffin as phase change material for battery thermal management

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Science Bulletin 2016年第5期61卷 391-400页

作者： Qiannan Zhang Yutao Huo zhonghao Rao School of Electric Power Engineering China University of Mining and Technology Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education Southeast University

With the large latent heat and low cost, the paraffin has been widely used in battery thermal management(BTM) system to improve the efficiency and cycling life of power battery. The numerical model of paraffin melting in a cavity has been established, and the effects on the solid–liquid phase change process have been investigated for the purpose of enhancing the heat transfer performance of paraffin-based BTM system. The results showed that the location of the heating wall had great effects on the melting process. The paraffin in the cavity melted most quickly when the heating wall located at the bottom. Furthermore, the effects of thermal conductivity and the velocity of the slip wall have been considered. The gradient of liquid fraction increased with the increase in thermal conductivity, and the melting process could be accelerated or delayed by the slip wall with different velocity.

关键词： Phase change material Battery thermal management Solid–liquid phase change Heat flux Thermal conductivity

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Effective Density-Based Clustering Algorithms for Incomplete Data

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Big Data Mining and Analytics 2021年第3期4卷 183-194页

作者： zhonghao Xue Hongzhi Wang USC Viterbi School of Engineering University of Southern CaliforniaLos AngelesCA 90007USA Department of Computer Science and Technology Harbin Institute of TechnologyHarbin 150001China

Density-based clustering is an important category among clustering algorithms. In real applications, many datasets suffer from incompleteness. Traditional imputation technologies or other techniques for handling missing values are not suitable for density-based clustering and decrease clustering result quality. To avoid these problems,we develop a novel density-based clustering approach for incomplete data based on Bayesian theory, which conducts imputation and clustering concurrently and makes use of intermediate clustering results. To avoid the impact of low-density areas inside non-convex clusters, we introduce a local imputation clustering algorithm, which aims to impute points to high-density local areas. The performances of the proposed algorithms are evaluated using ten synthetic datasets and five real-world datasets with induced missing values. The experimental results show the effectiveness of the proposed algorithms.

关键词： density-based clustering incomplete data clustering algorihtm

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Efficient CO_(2) electroreduction over N-doped hieratically porous carbon derived from petroleum pitch

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Journal of Energy Chemistry 2021年第5期30卷 113-120页

作者： hui Ning Dianliang Guo Xiaoshan Wang zhonghao Tan Wenhang Wang Zhongxue Yang Linqing Li Qingshan Zhao Jian Hao Mingbo Wu College of Chemical Engineering College of New EnergyInstitute of New EnergyState Key Laboratory of Heavy Oil ProcessingChina University of Petroleum(East China)Qingdao 266580ShandongChina Stare Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering Yinchuan 750021NingxiaChina

Developing of economic and efficient catalysts is critical for the application of electroreduction of carbon dioxide to highly valuable ***,we present a facile method to synthesize N-doped hieratically porous carbon through pyrolysis of petroleum pitch followed by ammonia *** found mesopores are favored formation by removing of asphaltene from petroleum pitch during the carbonation ***,ammonia etching can not only increase the pyridinic-N content,but also upgrade the ratio of meso-to micro-pores of carbon *** the N-doped hieratically porous carbon as catalyst for carbon dioxide electroreduction,the Faradaic efficiency of carbon monoxide reaches 83%at-0.9 V *** reversible hydrogen electrode(RHE)in 0.1 M KHCO_(3).This superior performance is attributed to the synergistic effects of highly pyridinic-N content in conjunction with the hieratically porous architecture,rendering abundant exposed and accessible active sites for electroreduction of CO_(2).Our work provides a new strategy for the large-scale preparation of high-performance,low-cost catalysts for CO_(2) electroreduction.

关键词： Petroleum pitch Carbon dioxide Electroreduction Porous carbon

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