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Journal of Thermal Science 2020年第4期29卷 868-883页

作者： SHU Ziyun WANG Feifei DAI Chong SI Jicang WANG Bo mi jianchun Department of Energy and Resource Engineering College of EngineeringPeking UniversityBeijing 100871China China Ship Development and Design Center Wuhan 430074China School of Environmental Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China

This study investigated the formation and emission characteristics of nitric oxide(NO) from flameless miLD(moderate or intensive low-oxygen dilution) combustion(miLDC) versus traditional visible-flame combustion(TC) in a 30-k W furnace. Both combustion processes were experimentally operated successively in the same furnace, burning natural gas at a fixed rate of 19 k W and the equivalence ratio of 0.86. Numerical simulations of TC and miLDC were carried out to explain their distinction in the measured furnace temperature and exhaust NO emissions. Present measurements of the NO emission(XNO) versus a varying furnace wall temperature(Tw) have revealed, at the first time, that the relationship of XNO ~ Tw was exponential in both TC and miLDC. By analyzing the simulated results, the average temperature over the reaction zone was identified to be the common characteristic temperature for scaling NO emissions of both cases. Moreover, relative to TC, miLDC had a fairly uniform temperature distribution and low peak temperature, thus reducing the NO emission by over 90%. The thermal-NO formation was found to contribute more than 70%-80% to the total XNO from TC while the N2O-intermediate route dominated the NO emission from miLDC.

关键词： miLD(moderate or intensive low-oxygen dilution)combustion traditional combustion NO emission

PIV measurements of turbulent jets issuing from triangular and circular orifice plates

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Science China(Physics,Mechanics & Astronomy) 2013年第6期56卷 1176-1186页

作者： XU minYi ZHANG JianPeng mi jianchun NATHAN G J KALT P A M Marine Engineering College Dalian Maritime University State Key Laboratory of Turbulence & Complex Systems College of EngineeringPeking University Centre for Energy Technology and School of Mechanical Engineering University of AdelaideSA 5005Australia

The present study experimentally investigated the near-field flow mixing characteristics of two turbulent jets issuing from equilateral triangular and circular orifice plates into effectively unbounded surroundings,*** particle image velocimetry(PIV) was applied to measure the velocity field at the same Reynolds number of Re=50,000,where Re = UeDe /with Ue being the exit bulk velocity and the kinematic viscosity of fluid,D e the equivalent *** instantaneous velocity,mean velocity,Reynolds stresses were *** the mean velocity field,the centreline velocity decay rate and half-velocity width were *** the mixing characteristics of the two jets,it is found that the triangular jet has a faster mixing rate than the circular *** triangular jet entrainments with the ambient fluid at a higher rate in the near *** is evidenced by a shorter unmixed core,faster Reynolds stress and centreline turbulence intensity *** primary coherent structures in the near field are found to break down more rapidly in the triangular jet as compared to the circular *** the entire measurement region,the triangular jet maintained a higher rate of decay and ***,all components of Reynolds stress of the triangular jet appear to reach their peaks earlier,and then decay more rapidly than those of the circular *** addition,the axis-switching phenomenon is observed in the triangular jet.

关键词： triangular jet turbulent mixing coherent structures axis-switching

On two distinct Reynolds number regimes of a turbulent square jet

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Theoretical & Applied Mechanics Letters 2015年第3期5卷 117-120页

作者： minyi Xu Jianpeng Zhang Pengfei Li jianchun mi Marine Engineering College Dalian Maritime University State Key Laboratory of Turbulence & Complex Systems College of EngineeringPeking University

The effects of Reynolds number on both large-scale and small-scale turbulence properties are investigated in a square jet issuing from a square pipe. The detailed velocity fields were measured at five different exit Reynolds numbers of 8 × 10^3 〈 Re 〈 5 × 10^4. It is found that both large-scale properties （e.g,, rates of mean velocity decay and spread） and small-scale properties （e.g., the dimensionless dissipation rate constant A = εL/（u^2）^3/2） are dependent on Re for Re ≤ 3 ×10^4 or Reλ ≤ 190, but virtually become Re-independent with increasing Re or Reλ. In addition, for Reλ 〉 190, the value ofA = εL/（u^2）^3/2 in the present square jet converges to 0.5, which is consistent with the observation in direct numerical simulations of box turbulence, but lower than that in circular jet, plate wake flows, and grid turbulence. The discrepancies in critical Reynolds number and A = εL/（u^2）^3/2 among different turbulent flows most likely result from the flow type and initial conditions.

关键词： Square jet Hot-wire Reynolds number Small-scale turbulence Mean energy dissipation rate

大湍流度对超低雷诺数下翼型受力及绕流的影响

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航空学报 2011年第1期32卷 41-48页

作者：王庶米建春北京大学湍流与复杂系统研究国家重点实验室北京100871

实验测量了超低雷诺数(Re=5 300)下NACA 0012翼型在自由来流下的升力系数和阻力系数,重点研究来流的湍流度对升力系数和阻力系数的影响,并进一步通过对翼型流场的研究揭示湍流度对翼型受力产生影响的机理。结果显示,低湍流度下升力系数... 详细信息

实验测量了超低雷诺数(Re=5 300)下NACA 0012翼型在自由来流下的升力系数和阻力系数,重点研究来流的湍流度对升力系数和阻力系数的影响,并进一步通过对翼型流场的研究揭示湍流度对翼型受力产生影响的机理。结果显示,低湍流度下升力系数和阻力系数均无失速特征;当湍流度提高,升力系数和阻力系数在12°～15°迎角下表现出明显的失速特征。翼型流场的流动显示表明,自由来流的湍流度不仅对翼型边界层的流动有明显影响,而且对边界层分离后的剪切层流动状态有很大影响,使得翼型在相同雷诺数和相同迎角下表现出完全不同的特性,并得出湍流度的增大和雷诺数的提高在影响翼型绕流形态及受力特征方面起着相似作用的结论。

关键词：湍流度超低雷诺数升力流动显示失速

A humidity resistant and high performance triboelectric nanogenerator enabled by vortex-induced vibration for scavenging wind energy

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Nano Research 2022年第4期15卷 3246-3253页

作者： Yan Wang Tianyu Chen Shuowen Sun Xiangyu Liu Zhiyuan Hu Zhenhui Lian Long Liu Qiongfeng Shi Hao Wang jianchun mi Tongming Zhou Chengkuo Lee minyi Xu Dalian Key Lab of Marine micro/Nano Energy and Self-powered System Marine Engineering CollegeDalian Maritime UniversityDalian 116026China Center for Intelligent Sensors and MEMS(CISM) National University of Singapore Engineering Drive 3 Singapore 117576Singapore3 College of EngineeringPeking UniversityBeijing 100871China School of Civil Environmental and Mining EngineeringThe University of Western AustraliaWA 6009Australia

Wind energy is a promising renewable energy source for a low-carbon *** study is to develop a fully packaged vortexinduced vibration triboelectric nanogenerator(VIV-TENG)for scavenging wind *** VIV-TENG consists of a wind vane,internal power generation unit,an external frame,four springs,a square cylinder and a circular *** internal power generation unit consists of polytetrafluoroethylene(PTFE)balls,a honeycomb frame and two copper *** from most of the previous wind energy harvesting TENGs,the bouncing PTFE balls are fully packaged in the square *** distinct design separates the process of contact electrification from the external environment,and at the same time avoids the frictional wear of the ordinary wind energy harvesting *** corresponding VIV parameters are investigated to evaluate their influence on the vibration behaviors and the energy *** state of the VIV-TENG corresponds to the high output performance from the *** distinct,robust structure ensures the full-packaged VIV-TENG can harvest wind energy from arbitrary directions and even in undesirable weather *** study proposes a novel TENG configuration for harvesting wind energy and the VIV-TENG proves promising powering micro-electro-mechanical appliances.

关键词： vortex-induced vibration wind energy triboelectric nanogenerator self-powered

Progress and recent trend in miLD combustion

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Science China(Technological Sciences) 2011年第2期54卷 255-269页

作者： LI PengFei mi jianchun DALLY B B WANG FeiFei WANG Lin LIU ZhaoHui CHEN Sheng ZHENG ChuGuang State Key Laboratory of Turbulence and Complex Systems Peking University Beijing 100871 China School of Mechanical Engineering University of Adelaide South Australia 5005 Australia State Key Laboratory of Coal Combustion Huazhong University of Science and Technology Wuhan 430074 China

Moderate or intense low oxygen dilution(miLD)combustion plays a significant role in the mitigation of combustion-generated pollutants and greenhouse gases whilst meeting thermal efficiency ***,due to the lack of the fundamental knowledge on this combustion,there is a misconception that miLD combustion should be established by high preheating of the air,which has limited its *** research and development on this combustion has been performed for several years. We have found that the requirements for establishing the miLD combustion are more relaxed than *** is also revealed that this combustion of different type,i.e.,non-premixed,partially premixed and fully premixed,can be achieved by firing various fuels(i.e.,gaseous,liquid and solid fuels).It is suggested that the application of the miLD combustion can be expanded *** present review summarizes the progress and recent trend made in the R&D of this combustion and recommends further fundamental studies for improving our knowledge and widening its applications.

关键词： high temperature air combustion flameless oxidation flameless combustion oxy-fuel combustion

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煤粉miLD燃烧的数值模型优化

中国电机工程学报 2016年第19期36卷 5245-5253,5406页

作者：梅振锋张健鹏米建春西安热工研究院有限公司苏州分公司江苏省苏州市215163 北京大学工学院北京市海淀区100871

采用用户自定义函数(UDF)对煤粉miLD燃烧的数值模型进行了优化,包括挥发分的多组分比拟、脱挥发分极限的温度依赖优化和煤粉颗粒燃烧过程的算法优化。通过与IFRF的煤粉miLD燃烧经典实验的对比,验证了模型优化所产生的效果。研究发现,挥... 详细信息

采用用户自定义函数(UDF)对煤粉miLD燃烧的数值模型进行了优化,包括挥发分的多组分比拟、脱挥发分极限的温度依赖优化和煤粉颗粒燃烧过程的算法优化。通过与IFRF的煤粉miLD燃烧经典实验的对比,验证了模型优化所产生的效果。研究发现,挥发分的多组分比拟能更准确地预测炉内O2浓度分布;脱挥发分极限的温度依赖优化,一方面能够使挥发分在低温区间开始脱附,改善模拟中着火延迟过长的问题,另一方面,能够使煤粉颗粒在高温区间脱附出更多的挥发分,使得温度分布的预测更为准确;煤粉颗粒燃烧过程的算法优化能够刻画挥发分脱附过程和焦炭反应过程在温度区间(780~1200K)上的重叠现象,能更准确地预测炉内CO分布,与真实的煤粉miLD燃烧过程更为相符。

关键词：煤粉 miLD燃烧数值模拟挥发分用户自定义函数

装置元件排列间距和颗粒浓度对细颗粒湍流聚并的影响

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中国电机工程学报 2016年第6期36卷 1625-1632页

作者：章鹏飞米建春潘祖明北京大学工学院北京市海淀区100871 武汉利康能源有限公司湖北省武汉市430074

通过数值模拟研究锯齿形元件组成的细颗粒聚并装置的湍流聚并特性,考察元件的排列间距和气流中颗粒物浓度对湍流聚并的影响。计算采用RANS模型,并获得了实验的验证。模拟结果表明,元件阵列的排列既不能过于紧密也不能过于稀疏,需要兼顾... 详细信息

通过数值模拟研究锯齿形元件组成的细颗粒聚并装置的湍流聚并特性,考察元件的排列间距和气流中颗粒物浓度对湍流聚并的影响。计算采用RANS模型,并获得了实验的验证。模拟结果表明,元件阵列的排列既不能过于紧密也不能过于稀疏,需要兼顾空间利用率、元件产涡的耦合作用和流动阻力三方面的考虑。实际应用也需要考虑颗粒浓度的影响,模拟发现:浓度越高,颗粒的湍流聚并效果越好;当浓度足够高时,Z形锯齿元件组成的聚并装置能聚并近50%的小颗粒,具有实用价值。

关键词：细颗粒物湍流聚并效率颗粒浓度

烟气流速和装置元件角度对细颗粒湍流聚并的影响

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中国电机工程学报 2016年第10期36卷 2714-2720页

作者：章鹏飞米建春潘祖明北京大学工学院北京市海淀区100871 武汉利康能源有限公司湖北省武汉市430074

颗粒物湍流聚并技术是促进细颗粒物脱除的有效手段。通过数值模拟研究在一种装置内颗粒物在湍流作用下的聚并特性,考察气流速度和装置元件角度的影响。模拟结果表明:聚并的效果随着流速的增大而提高,也随着元件迎流角度接近90?而提高。... 详细信息

颗粒物湍流聚并技术是促进细颗粒物脱除的有效手段。通过数值模拟研究在一种装置内颗粒物在湍流作用下的聚并特性,考察气流速度和装置元件角度的影响。模拟结果表明:聚并的效果随着流速的增大而提高,也随着元件迎流角度接近90?而提高。原因是:上述装置结构和流速的变化提高了元件的尾涡强度,使湍动能耗散率增大,也使颗粒之间的碰撞概率增大。

关键词：细颗粒物湍流聚并效率流速角度

Numerical Simulation of Flameless Premixed Combustion with an Annular Nozzle in a Recuperative Furnace

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Chinese Journal of Chemical Engineering 2010年第1期18卷 10-17页

作者：米建春李鹏飞郑楚光 State Key Laboratory of Turbulence and Complex Systems Department of Energy-& Resources Engineering College of Engineering Peking University Beijing 100871 China State Key Laboratory of Coal Combustion Huazhong University of Science and Technology Wuhan 430074 China

This paper reports an investigation of Computational Fluid Dynamics(CFD)on the influence of injection momentum rate of premixed air and fuel on the flameless Moderate or Intense Low oxygen Dilution(miLD) combustion in a recuperative *** of the furnace flow velocity,temperature,O2,CO2 and NOx concentrations are *** obtained suggest that the flue gas recirculation plays a vital role in establishing the premixed miLD *** is also revealed that there is a critical momentum rate of the fuel-air mixture below which miLD combustion does not ***,the momentum rate appears to have less significant influence on conventional global combustion than on miLD combustion.

关键词： flameless oxidation premixed combustion numerical simulation