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Experimental investigation on upstream-injection interaction with a scramjet cavity flameholder

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Chinese Science Bulletin 2014年第14期59卷 1568-1574页

作者： ming-bo sun Shun-Ping Zhang Yan-Hui Zhao Yu-Xin Zhao Jian-Han Liang Science and Technology on Scramjet Laboratory National University of Defense Technology

The study has evaluated the coherent structures and the velocity field of gaseous transverse jet upstream of a scramjet flameholder in a supersonic turbulent *** high spatiotemporal resolution coherent structures of the jet plume/wakes and the cavity shear layer were obtained by utilizing the nanoparticle-based planar laser scattering *** to the no upstream injection case,the cavity shear layer downstream of the jet shows significant mass exchange with *** particle image velocimetry velocity field and the velocity profiles demonstrated that the interaction intensity of the cavity shear layer with the upstream injection is further enhanced as the injection stagnation pressure increases.

关键词：超燃冲压发动机相互作用强度火焰稳定器上游实验激光散射技术横向喷流相干结构

Stabilization mechanisms of lifted flames in a supersonic stepped-wall jet combustor

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2021年第4期22卷 314-330页

作者： Jin-cheng ZHANG ming-bo sun Zhen-guo WANG Hong-bo WANG Chao-yang LIU Science and Technology on Scramjet Laboratory National University of Defense TechnologyChangsha 410073China

Flame stabilization is the key to extending scramjets to hypersonic speeds;accordingly,this topic has attracted much attention in theoretical research and engineering *** study performed large eddy simulations(LESs)of lifted hydrogen jet combustion in a stepped-wall combustor,focusing on the flame stabilization mechanisms,especially for the autoignition *** assumed probability density function(PDF)approach was used to close the subgrid chemical reaction *** reliability of the solver was confirmed by comparing the LES results with experimental data and published simulated *** hydrogen jet and the incoming stream were first mixed by entraining large-scale vortices in the shear layer,and stable combustion in the near-wall region was achieved downstream of the flame induction *** autoignition cascade is a transition of fuel-rich flame to stoichiometric ratio flame that plays a role in forming the flame base,which subsequently causes downstream flame *** cases with different jet total temperatures are compared,and the results show that the increase in the total temperature reduces the lift-off distance of the *** the highest total temperature case,an excessively large scalar dissipation rate inhibits the autoignition cascade,resulting in a fuel-rich low-temperature flame.

关键词： Large eddy simulation(LES) Autoignition Lifted flame Flame stabilization Assumed probability density function(PDF)

Efficient WENOCU4 scheme with three different adaptive switches

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2020年第9期21卷 695-720页

作者： Liang LI Hong-bo WANG Guo-yan ZHAO ming-bo sun Da-peng XIONG Tao TANG Science and Technology on Scramjet Laboratory National University of Defense TechnologyChangsha 410073China

Although classical WENOCU schemes can achieve high-order accuracy by introducing a moderate constant parameter C to increase the contribution of optimal weights,they exhibit distinct numerical dissipation in smooth *** study presents an extension of our previous research which confirmed that adaptively adjusting parameter C can indeed overcome the inadequacy of the usage of a constant small *** is applied near a discontinuity while Cmax is used elsewhere and they are switched according to the variation of the local flow-field *** study provides the reference values of the adaptive parameter C of WENOCU4 and systematically evaluates the comprehensive performance of three different switches(labeled as the binary,continuous,and hyperbolic tangent switches,respectively)based on an optimized efficient WENOCU4 scheme(labeled as EWENOCU4).Varieties of 1D scalar equations,empirical dispersion relation analysis,and multi-dimensional benchmark cases of Euler equations are ***,the dissipation and dispersion properties of these three switches are ***,employing the binary switch,EWENOCU4 achieves the best comprehensive ***,the binary switch can efficiently filter more misidentifications in smooth regions than others do,particularly for the cases of 1 D scalar equations and Euler ***,the computational efficiency of the binary switch is superior to that of the hyperbolic tangent ***,the optimized scheme exhibits high-resolution spectral properties in the wavenumber ***,employing the binary switch is a more cost-effective improvement for schemes and is particularly suitable for the simulation of complex shock/turbulence *** study provides useful guidance for the reference values of parameter C and the evaluation of adaptive switches.

关键词： WENOCU4 Shock-capturing schemes Adaptive switch Numerical robustness Dissipation

Numerical study on cavity ignition process in a supersonic combustor

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2020年第10期21卷 848-858页

作者： Yong-chao sun Zun CAI Tai-yu WANG ming-bo sun Cheng GONG Yu-hui HUANG Science and Technology on Scramjet Laboratory College of Aerospace Science and EngineeringNational University of Defense TechnologyChangsha 410073China China Aerodynamics Research and Development Center Mianyang 621000China

Large eddy simulations(LESs)of cavity ignition processes were performed in a 2 D ethylene-fueled supersonic combustor with a single rear-wall-expansion cavity based on *** ethylene combustion was modelled using a 35-step with 20-specie ethylene chemical mechanism,which had been validated by CHEMKIN *** effect on the ignition process of different ignition sites inside the cavity was then *** was found that the rear region of the cavity floor is an optimized ignition site where successful ignitions will be *** to different ignition behaviors,two flame extinguishing modes could be identified:blown-off extinguishing mode and flow dissipation extinguishing ***-off extinguishing mode mainly occurred after ignition near the cavity shear layer,in which the initial flame was blown off directly due to the high speed of the supersonic core *** dissipation extinguishing mode is likely to occur after ignition near the front and middle cavity floor as a result of severe turbulent dissipations and limited chemical *** study indicates that the movement routine of the initial flame is important for the ignition process,including both moving towards a favorable flow field and forming a large heat release region along the movement.

关键词： Ignition process Cavity Supersonic combustor Numerical study

火箭基组合循环发动机总体布局研究进展（英文）

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2019年第3期20卷 163-183页

作者： Tian-tian ZHANG Zhen-guo WANG Wei HUANG Jian CHEN ming-bo sun Department of Aerospace Science and Engineering National University of Defense Technology

本综述从总体布局层面综述火箭基组合循环(RBCC)发动机在各个国家的发展现状,旨在展现该型发动机在单级入轨任务中的发展前景,为设计组合循环发动机以及进行空天往返任务规划提供参考。本文将RBCC按照构型特点进行归类并举例介绍,概述... 详细信息

本综述从总体布局层面综述火箭基组合循环(RBCC)发动机在各个国家的发展现状,旨在展现该型发动机在单级入轨任务中的发展前景,为设计组合循环发动机以及进行空天往返任务规划提供参考。本文将RBCC按照构型特点进行归类并举例介绍,概述了发动机-机身一体化设计情况,并简要介绍了RBCC动力飞行器的任务规划和多目标优化方法。当前,尽管RBCC的研究面临着很多艰难的挑战,但是RBCC具有单级入轨的潜力,能够降低空天往返的成本。对RBCC发动机系统中各个子系统的研究也有利于促进其他相关学科的发展。

关键词：火箭基组合循环发动机单级入轨空天往返发动机-机身一体化

Traffic safety helmet wear detection based on improved YOLOv5 network

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Optoelectronics Letters 2025年第1期21卷 35-42页

作者： GUI Dongdong sun bo College of Software Southeast UniversitySuzhou 215123China Quanzhou Equipment Research Centre Haixi InstituteChinese Academy of SciencesQuanzhou 350108China

Aiming at the problem that the current traffic safety helmet detection model can't balance the accuracy of detection with the size of the model and the poor generalization of the model,a method based on improving you only look once version 5(YOLOv5) is *** incorporating the lightweight Ghost Net module into the YOLOv5 backbone network,we effectively reduce the model *** addition of the receptive fields block(RFB) module enhances feature extraction and improves the feature acquisition capability of the lightweight ***,the high-performance lightweight convolution,GSConv,is integrated into the neck structure for further model size ***,the baseline model's loss function is substituted with efficient insertion over union(EIoU),accelerating network convergence and enhancing detection *** results corroborate the effectiveness of this improved algorithm in real-world traffic scenarios.

关键词： network union backbone

Geometric-like imaginarity:Quantification and state conversion

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Science China(Physics,Mechanics & Astronomy) 2025年第2期68卷 13-22页

作者： Meng-Li Guo bo Li Shao-ming Fei School of Science East China University of TechnologyNanchang 330006China School of Computer and Computing Science Hangzhou City University Hangzhou 310015China School of Mathematical Sciences Capital Normal UniversityBeijing 100048China

From the perspective of resource-theoretic approach,this study explores the quantification of imaginary in quantum *** propose a well defined measure of imaginarity,the geometric-like measure of *** with the usual geometric imaginarity measure,this geometric-like measure of imaginarity exhibits smaller decay difference under quantum noisy channels and higher *** applications,we show that both the optimal probability of state transformations from a pure state to an arbitrary mixed state via real operations,and the maximal probability of stochastic-approximate state transformations from a pure state to an arbitrary mixed state via real operations with a given fidelity f,are given by the geometric-like measure of imaginarity.

关键词： quantum resource theory imaginarity geometric-like channels state transformations

Recycling Fe and improving organic pollutant removal via in situ forming magnetic core-shell Fe_(3)O_(4)@CaFe-LDH in Fe(Ⅱ)-catalyzed oxidative wastewater treatment

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Journal of Environmental Sciences 2025年第1期147卷 523-537页

作者： Ting He Jie sun Liangwei Deng Jialin ming Changwei Hu Key Laboratory of Green Chemistry and Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu 610064China Biogas Institute of Ministry of Agriculture and Rural Affairs Chengdu 610041China Inner Mongolia Key Laboratory of Fine Organic Synthesis Inner Mongolia UniversityHohhot 010021China

Due to its high efficiency,Fe(Ⅱ)-based catalytic oxidation has been one of the most popular types of technology for treating growing organic pollutants.A lot of chemical Fe sludge alongwith various refractory pollutantswas concomitantly produced,whichmay cause secondary environmental problemswithout proper *** here innovatively proposed an effective method of achieving zero Fe sludge,reusing Fe resources(Fe recovery=100%)and advancing organics removal(final TOC removal>70%)simultaneously,based on the in situ formation of magnetic Ca-Fe layered double hydroxide(Fe_(3)O_(4)@CaFe-LDH)***(Ca^(2+)and Fe^(3+))concentration(≥30 mmol/L)and their molar ratio(Ca:Fe≥1.75)were crucial to the success of the *** nano Fe_(3)O_(4)was designed to be involved in the Fe(Ⅱ)-catalytic wastewater treatment process,and was modified by oxidation intermediates/products(especially those with COO-structure),which promoted the co-precipitation of Ca^(2+)(originated from Ca(OH)_(2)added after oxidation process)and byproduced Fe^(3+)cations on its surface to in situ generate core-shell Fe_(3)O_(4)@*** oxidation products were further removed during Fe_(3)O_(4)@CaFe-LDH material formation via intercalation and *** applicable to many kinds of organicwastewater,such as bisphenol A,methyl orange,humics,and biogas *** prepared magnetic and hierarchical CaFe-LDH nanocomposite material showed comparable application performance to the recently reported *** work provides a new strategy for efficiently enhancing the efficiency and economy of Fe(Ⅱ)-catalyzed oxidative wastewater treatment by producing high value-added LDHs materials.

关键词： CaFe layered double hydroxide Fe(Ⅱ)-catalytic oxidation Fe recycling Magnetic nanomaterial in situ formation Fe_(3)O_(4)modification

ICA-Net: improving class activation for weakly supervised semantic segmentation via joint contrastive and simulation learning

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Optoelectronics Letters 2025年第3期21卷 188-192页

作者： YE Zhuang LIU Ruyu sun bo School of Information Engineering Chengdu Aviation Vocational and Technical College School of Computer Science and Engineering Hangzhou Normal University Quanzhou Institute of Equipment Manufacturing Haixi Institutes Chinese Academy of Sciences

In the field of optoelectronics, certain types of data may be difficult to accurately annotate, such as high-resolution optoelectronic imaging or imaging in certain special spectral ranges. Weakly supervised learning can provide a more reliable approach in these situations. Current popular approaches mainly adopt the classification-based class activation maps (CAM) as initial pseudo labels to solve the task.

关键词： A