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Numerical simulation of the thermal non-equilibrium flow-field characteristics of a hypersonic Apollo-like vehicle

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Chinese Physics B 2022年第9期31卷 376-385页

作者： minghao yu Zeyang Qiu Bo Lv Zhe Wang Faculty of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048China

In order to investigate the relationship between the flow-field parameters outside the vehicle and the altitude,this paper takes the Atmospheric Reentry Demonstrator(ARD)with an angle of attack of-20°as the research object and adopts a two-temperature model coupled with the shear-stress transport k-ωturbulence model to focus on the variation of flow-field parameters including flow-field pressure,Mach number and temperature with the reentry *** is found that the flow-field high-pressure region and low-Mach region both appear in the shock layer near the head of the ARD,while the maximum pressure of the surface appears on the windward side of the ARD's head with a toroidal distribution,and the numerical magnitude is inversely proportional to the radius of the *** fluid through the shoulder of the ARD flow expansion plays a dominant role,the airflow velocity increases,the Mach number of the windward side of the rear cone increases and the flow-field pressure and surface pressure rapidly *** the fluid passes through the shock layer,the translational-rotation temperature will increase before the vibration-electron temperature,there is a thermal non-equilibrium effect and the two temperatures will rapidly decrease again when approaching the surface of the ARD due to the existence of temperature *** the same time,both the windward side of the shoulder and the back cover of the ARD suffer from a large thermal load and require thermal protection.

关键词： atmospheric reentry demonstrator reentry altitude flow-field characteristics two-temperature model

Electronic structure regulation of noble metal-free materials toward alkaline oxygen electrocatalysis

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eScience 2023年第4期3卷 20-38页

作者： Xia Wang minghao yu Xinliang Feng Max-Planck-Institute for Chemical Physics of Solids 01187 DresdenGermany Centre for Advancing Electronics Dresden(CFAED)&Faculty of Chemistry and Food Chemistry Technische Universit€at Dresden01062 DresdenGermany Max Planck Institute of Microstructure Physics 06120 HalleGermany

Developing highly efficient,inexpensive catalysts for oxygen electrocatalysis in alkaline electrolytes(i.e.,the oxygen reduction reaction(ORR)and the oxygen evolution reaction(OER))is essential for constructing advanced energy conversion techniques(such as electrolyzers,fuel cells,and metal–air batteries).Recent achievements in efficient noble metal-free ORR and OER catalysts make the replacement of conventional noble metal counterparts a realistic *** particular,various electronic structure regulation strategies have been employed to endow these oxygen catalysts with attractive physicochemical properties and strong synergistic effects,providing significant fundamental understanding to advance in this *** review article summarizes recently developed electronic structure regulation strategies for three types of noble metal-free oxygen catalysts:transition metal compounds,single-atom catalysts,and metal-free *** begin by briefly presenting the basic ORR and OER reaction mechanisms,following this with an analysis of the fundamental relationship between electronic structure and intrinsic electrocatalytic activity for the three categories of ***,recent advances in electronic structure regulation strategies for noble metal-free ORR and OER catalysts are systematically *** conclude by summarizing the remaining challenges and presenting our outlook on the future for designing and synthesizing noble metal-free oxygen electrocatalysts.

关键词： Oxygen electrocatalysts Electronic structure Noble metal-free electrocatalysts Active sites Intrinsic activity

Thermochemical Nonequilibrium 2D Modeling of Nitrogen Inductively Coupled Plasma Flow

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Plasma Science and Technology 2015年第9期17卷 749-760页

作者： yu minghao yusuke TAKAHASHI Hisashi KIHARA Ken-ichi ABE Kazuhiko YAMADA Takashi ABE Satoshi MIYATANI Department of Aeronautics and Astronautics Kyushu University Division of Mechanical and Space Engineering Hokkaido University Institute of Space and Astronautical Science Japan Aerospace Exploration Agency Department of Aeronautics and Astronautics The University of Tokyo

Two-dimensional（2D） numerical simulations of thermochemical nonequilibrium inductively coupled plasma（ICP） flows inside a 10-kW inductively coupled plasma wind tunnel（ICPWT） were carried out with nitrogen as the working *** axisymmetric NavierStokes（N-S） equations coupled with magnetic vector potential equations were solved.A fourtemperature model including an improved electron-vibration relaxation time was used to model the internal energy exchange between electron and heavy *** third-order accuracy electron transport properties（3rd AETP） were applied to the simulations.A hybrid chemical kinetic model was adopted to model the chemical nonequilibrium *** flow characteristics such as thermal nonequilibrium,inductive discharge,effects of Lorentz force were made clear through the present *** was clarified that the thermal nonequilibrium model played an important role in properly predicting the temperature *** prediction accuracy can be improved by applying the 3rd AETP to the simulation for this ICPWT.

关键词： inductively coupled plasma nonequilibrium electron transport properties,magnetic vector potential

Turbulent drag reduction by spanwise slot blowing pulsed plasma actuation

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Plasma Science and Technology 2022年第11期24卷 26-36页

作者： Borui ZHENG yuanzhong JIN minghao yu yueqiang LI Bin WU Quanlong CHEN School of Automation and Information Engineering Xi’an University of TechnologyXi’an 710048People’s Republic of China Department of Aeronautics and Astronautics Northwestern Polytechnical UniversityXi’an 710072People’s Republic of China The Green Aerotechnics Research Institute of Chongqing Jiaotong University Chongqing 401120People’s Republic of China

This work studies the turbulent drag reduction(TDR)effect of a flat plate model using a spanwise slot blowing pulsed plasma actuator(SBP-PA).Wind tunnel experiments are carried out under a Reynolds number of 1.445×10^(4).Using a hot-wire anemometer and an electrical data acquisition system,the influences of millisecond pulsed plasma actuation with different burst frequencies and duty cycles on the microscale coherent structures near the wall of the turbulent boundary layer(TBL)are *** experimental results show that the SBP-PA can effectively reduce the frictional drag of the *** the duty cycle exceeds 30%,the TDR rate is greater than 11%,and the optimal drag reduction rate of 13.69%is obtained at a duty cycle of 50%.Furthermore,optimizing the electrical parameters reveals that increasing the burst frequency significantly reduces the velocity distribution in the logarithmic region of the *** the normalized burst frequency reaches f+=2πf_(p)d/U_(∞)=7.196,the optimal TDR effectiveness is 16.97%,indicating a resonance phenomenon between the pulsed plasma actuation and the microscale coherent structures near the ***,reasonably selecting the electrical parameters of the plasma actuator is expected to significantly improve the TDR effect.

关键词： turbulent boundary layer control plasma flow control hot-wire turbulent frictional drag turbulent drag reduction

Freestanding MXene-based macroforms for electrochemical energy storage applications

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SusMat 2023年第4期3卷 471-497页

作者： Qiongqiong Lu Congcong Liu Yirong Zhao Wengao Pan Kun Xie Pengfei yue Guoshang Zhang Ahmad Omar Lixiang Liu minghao yu Daria Mikhailova Institute of Materials Henan Key Laboratory of Advanced Conductor MaterialsHenan Academy of SciencesZhengzhouHenanChina Leibniz Institute for Solid State and Materials Research(IFW)Dresden e.V. DresdenGermany School of Physical Science and Technology Lanzhou UniversityLanzhouChina School of Engineering Westlake UniversityHangzhouZhejiangChina Faculty of Chemistry and Food Chemistry&Center for Advancing Electronics Dresden Technische Universität DresdenDresdenGermany

Freestanding MXene-based macroforms have gained significant attention as versatile components in electrochemical energy storage applications owing to their interconnected conductive network,strong mechanical strength,and customizable surface chemistries derived from MXene *** comprehensive review article encompasses key aspects related to the synthesis of MXene nanosheets,strategies for structure design and surface medication,surface modification,and the diverse fabrication methods employed to create freestanding MXene-based macroform *** review also delves into the recent advancements in utilizing freestanding MXene macroforms for electrochemical energy storage applications,offering a detailed discussion on the significant progress achieved thus ***,the correlation between the macroform’s structural attributes and its performance characteristics is thoroughly explored,shedding light on the critical factors influencing efficiency and *** the remarkable development,the review also highlights the existing challenges and presents future perspectives for freestanding MXenebased macroforms in the realms of high-performance energy storage *** addressing these challenges and leveraging emerging opportunities,the potential of freestanding MXene-based macroforms can be harnessed to enable groundbreaking advancements in the field of energy storage.

关键词： batteries electrochemical energy storage freestanding macroforms MXenes supercapacitors

Amplification Method of Lung Nodule Data Based on DCGAN Generation Algorithm

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国际计算机前沿大会会议论文集 2020年第1期 563-576页

作者： minghao yu Lei Cai Liwei Gao Jingyang Gao College of Information Science and Technology Beijing University of Chemical TechnologyBeijing 100029China Department of Radiation Oncology China-Japan Friendship HospitalBeijing 100029China

Early diagnosis of lung cancer can effectively reduce the mortality of *** use low-dose spiral CT to detect lung nodules,which is timeconsuming and prone to *** learning has achieved good results in the field of medical image sub-processing,which can reduce the pressure of doctors to a certain ***,in the actual lung CT images,the images containing lung nodules account for less than 1%of the total *** lack of data increases the difficulty of detecting lung nodules by using deep learning *** paper proposes an amplification method using deep convolutional anti-generation network(DCGAN)to generate lung nodule *** with different amplification methods,and the effectiveness of this method is *** can prove that the use of DCGAN to generate data can better solve the problems of high false positive rate and low sensitivity of lung nodule classification than the graphical data amplification *** with the existing methods,this experimental method greatly improves the accuracy,sensitivity and F1 score of lung nodule detection,and achieves good results of 99.98%,99.15%and 99.55%,respectively.

关键词： Lung nodule DCGAN Data amplification

Robotic Grasp Detection Using Light-weight CNN Model

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Robotic Grasp Detection Using Light-weight CNN Model

Flow control performance evaluation of a tri-electrode sliding discharge plasma actuator

第32届中国控制与决策会议

作者： Yang Jiang Xulong Li minghao yu Zhongyu Bai Faculty of Robot Science and Engineering Northeastern University

Manipulating objects is the premise of many robotic applications,such as assembly,sort and *** programming is widely used in industrial robot,it is necessary to improve the intelligent level of *** this paper,we propose an accurate,real-time,light-weight convolutional neural network SqueezeNet-RCM to predict a grasp configuration from a RGB and aligned depth image of graspable *** of using sliding window or regional proposal network to generate potential bounding box,we use a way of end-to-end to train and test our *** the standard Cornell Grasping Dataset,our model achieves accuracy of 90.1% and 88.6% on image-wise split and objectwise split respectively,speed at 73 frames per second(fps) on GPU inferencing,which could meet the requirement of ***,our model size is 2.9 MB,which is able to fit the memory to limited environment such as FPGA.

关键词： Grasp Detection Robotic Grasping SqueezeNet-RCM SqueezeNet CNN

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Chinese Physics B 2023年第9期32卷 348-355页

作者：郑博睿刘园鹏喻明浩金元中张倩陈全龙 School of Automation and Information Engineering Xi'an University of TechnologyXi'an 710048China School of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048China The Green Aerotechnics Research Institute of Chongqing Jiaotong University Chongqing 401120China

Tri-electrode sliding discharge(TED)plasma actuators are formed by adding a direct current(DC)exposed electrode to conventional dielectric barrier discharge(DBD)plasma *** are three TED modes depending on the polarity and amplitude of the DC supply:DBD discharge,extended discharge and sliding *** paper evaluates the electrical,aerodynamic and mechanical characteristics of a TED plasma actuator based on energy analysis,particle image velocimetry experiments and calculations using the Navier-Stokes *** flow control performances of different discharge modes are quantitatively analyzed based on characteristic *** results show that flow control performance in both extended discharge and sliding discharge is more significant than that of DBD,mainly because of the significantly higher(up to 141%)body force of TED compared with ***,conductivity loss is the primary power loss caused by the DC polarity for TED ***,power consumption can be reduced by optimizing the dielectric material and thickness,thus improving the flow control performance of plasma actuators.

关键词： plasma flow control tri-electrode sliding discharge particle image velocimetry(PIV) performance evaluation

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飞行器大气再入过程中黑障缓解方法综述

中国空间科学技术 2022年第2期42卷 1-12页

作者：喻明浩邱泽洋西安理工大学机械与精密仪器工程学院西安710048

为了方便研究人员更好地掌握黑障的缓解方法及其研究现状,系统地介绍了目前航天领域中用于缓解黑障的多种技术方法。首先,简要介绍了黑障的成因以及研究现状,并阐述了电磁波在等离子体中的传播机理;其次,详细说明了14种黑障缓解方法的... 详细信息

为了方便研究人员更好地掌握黑障的缓解方法及其研究现状,系统地介绍了目前航天领域中用于缓解黑障的多种技术方法。首先,简要介绍了黑障的成因以及研究现状,并阐述了电磁波在等离子体中的传播机理;其次,详细说明了14种黑障缓解方法的基本原理及其优缺点,这些方法包括改变空气动力学形状、引入正交电磁场、驻波检测法、提高入射频率以及太赫兹法等。随后,从功耗、尺寸质量、通信效果以及工程实用性等6个方面对每种方法进行了分类评估。最后,针对黑障问题后续的研究方向,提出了几点建议。

关键词：再入飞行器等离子体鞘层黑障缓解方法方法评估

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