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Flow instability of supercritical hydrocarbon fuel in a multi-channel cooling system

Chinese Journal of Aeronautics 2024年第2期37卷 283-295页

作者： Yichao JIN Kun WU xuejun fan Institute of Applied Physics and Computational Mathematics Beijing 100094China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Thermally-induced flow instabilities are a critical issue in multi-channel regenerative cooling *** particular,the interactions between Density-Wave Oscillations(DWO)and Flow Maldistribution(FMD)can result in complex and disastrous instability *** study investigates the instability behaviors of hydrocarbon fluid in a four-channel system with a constant heat flux ratio using both frequency-and time-domain *** the heat flux increases,the in-tube flow sequentially destabilizes in each channel and converges to new equilibrium states,leading to the emergence of FMD *** also causes the system eigenvalue to change repeatedly from negative to positive rather than increasing ***,the system eigenvalues are between those of the two most unstable channels,indicating that the stability behavior of the entire system is dictated by the most unstable *** FMD occurs,flow oscillations are activated in channels with weak stability,and the in-tube flow is observed to evolve into various flow patterns,including stable flow,self-sustained oscillation,oscillation divergence,quasiperiodic oscillation,and oscillation *** novel instability mode of oscillation excursion involves a spontaneous transition of operating *** oscillates from an equilibrium state and then stabilizes at a new operational state after oscillation-induced ***,the newfound stable state may also be only temporary,with the in-tube flow regressing to the initial state,resulting in quasi-periodic oscillation.

关键词： Cooling Supercritical fluids Hydrocarbons Flow instability Flow maldistribution Density-wave oscillations

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Thermal cracking of aviation kerosene for scramjet applications

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Science China(Technological Sciences) 2009年第9期52卷 2644-2652页

作者： ZHONG FengQuan fan xuejun YU Gong LI JianGuo Key Laboratory of High Temperature Gas Dynamics(LHD) Institute of MechanicsChinese Academy of SciencesBeijing 100190China

Thermal cracking of China No.3 aviation kerosene was studied experimentally and analytically under supercritical conditions relevant to regenerative cooling system for Mach-6 scramjet applications. A two-stage heated tube system with cracked products collection/analysis was used and it can achieve a fuel temperature range of 700―1100 K,a pressure range of 3.5―4.5 MPa and a residence time of ap-proximately 0.5―1.3 s. Compositions of the cracked gaseous products and mass flow rate of the kerosene flow at varied temperatures and pressures were obtained experimentally. A one-step lumped model was developed with the cracked mixtures grouped into three categories:unreacted kerosene,gaseous products and residuals including liquid products and carbon deposits. Based on the model,fuel conversion on the mass basis,the reaction rate and the residence time were estimated as functions of temperature. Meanwhile,a sonic nozzle was used for the control of the mass flow rate of the cracked kerosene,and correlation of the mass flow rate gives a good agreement with the measurements.

关键词： thermal cracking aviation kerosene lumped model scramjet applications

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Research on the Damage of Porosityand Permeabilitydue to Perforation on Sandstone in the Compaction Zone

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Computers, Materials & Continua 2016年第1期51卷 21-42页

作者： Shifeng Xue Xiuxing Zhu Lin Zhang Shenghu Zhu Guigen Ye xuejun fan Departmentof Engineering Mechanics China University of PetroleumQingdao 266580China Well Logging Company ShengliOil Engineering Co.Ltd.Dongying 257000China Schlumberger Drilling Dynamic Solution Beijing 100022China Department of Mechanical Engineering Lamar UniversityBeaumontTX 77710USA

A perforating hole is a channel through which the oil and gas in a reservoir pass into the production well *** the process of perforating due to explosion,the surrounding sandstone will be damaged to a certain extent,which will increase the well bore skin and lead to the decrease of production *** this work a mechanical model of perforating damage is developed to describe the influences of perforating due to explosion on the porosity and permeability of the surrounding sandstone near the compaction *** on this developed model,the important data related to the damage of sandstone,such as matrix effective stress,plastic deformation,volumetric strain,and so on,can be numerically *** the behaviors of plasticity kinematic hardening at high strain rate due to impact loads,which are the important characteristics in the sandstone,is taken into account in this developed *** numerical and testing results show that the damage due to perforation in the sandstone can be accurately predicted by the developed model together with the porosity and permeability evolving model of perforation in a compaction *** a practical application,a methodology for the analysis of damage of porosity and permeability around a perforation tunnel is supposed based on the developed model and the core flow efficiency test of interparticle pore spaced sandstone target in China Shengli Oilfield and the computed tomography test.

关键词： zone. sandstone reservoir

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A CATASTROPHE ANALYSIS ON THE STABILITY OF THE CRACK GROWTH IN THREE-POINT BENDING SPECIMENS

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Acta Mechanica Solida Sinica 1996年第2期9卷 179-183页

作者： Wei Demin fan xuejun, Taiyuan Unversity of Technology, Taiyuan 030024 Taiyuan University of Technology Taiyuan 030024

This paper presents an attempt at the application of catastrophe theory to the stability analysis of J-controlled crack growth in three-point bending specimens. By introducing the solutions of J-integral in the completely yielding state for the ideal plastic material, the critical condition of losing stability for the crack propagation in the specimen is obtained, based on the cusp catastrophe theory. The process of the crack growth from geometrical sense is described.

关键词： crack growth stability cusp catastrophe J-integral three-point bending specimen

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Prognostics of radiation power degradation lifetime for ultraviolet light-emitting diodes using stochastic data-driven models

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Energy and AI 2021年第2期4卷 91-100页

作者： Jiajie fan Zhou Jing Yixing Cao Mesfin Seid Ibrahim Min Li xuejun fan Guoqi Zhang Institute of Future Lighting Academy for Engineering&TechnologyFudan UniversityShanghai 200433China Shanghai Research Center for Silicon Carbide Power Devices Engineering&Technology Fudan UniversityShanghai 200433China College of Mechanical and Electrical Engineering Hohai UniversityChangzhou 213022China EEMCS Faculty Delft University of TechnologyDelft 2628the Netherlands Changzhou Institute of Technology Research for Solid State Lighting Changzhou 213161China Department of Industrial and System Engineering The Hong Kong Polytechnic UniversityHung HomHong Kong Department of Mechanical Engineering Lamar UniversityBeaumontTX 77710USA

With their advantages of high efficiency,long lifetime,compact size and being free of mercury,ultraviolet light-emitting diodes(UV LEDs)are widely applied in disinfection and purification,photolithography,curing and biomedical ***,it is challenging to assess the reliability of UV LEDs based on the traditional life test or even the accelerated life *** this paper,radiation power degradation modeling is proposed to estimate the lifetime of UV LEDs under both constant stress and step stress degradation *** data-driven predic-tions with both Gamma process and Wiener process methods are implemented,and the degradation mechanisms occurring under different aging conditions are also *** results show that,compared to least squares regression in the IESNA TM-21 industry standard recommended by the Illuminating Engineering Society of North America(IESNA),the proposed stochastic data-driven methods can predict the lifetime with high accuracy and narrow confidence intervals,which confirms that they provide more reliable information than the IESNA TM-21 standard with greater robustness.

关键词： Ultraviolet light-emitting diodes(UV LEDs) Degradation modeling Gamma process Wiener process IESNA TM-21

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HER3 intracellular domains play a crucial role in HER3/HER2 dimerization and activation of downstream signaling pathways

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Protein & Cell 2012年第10期3卷 781-789页

作者： Byung-Kwon Choi Xiumei Cai Bin Yuan Zhao Huang xuejun fan Hui Deng Ningyan Zhang Zhiqiang An Texas Therapeutics Institute Brown Foundation Institute of Molecular MedicineUniversity of Texas Health Science Center at HoustonHoustonTX 77030USA Department of Biochemistry and Molecular Biology Shanghai Medical CollegeFudan UniversityShanghai 200032China The Methodist Hospital Research Institute HoustonTX 77030USA

Dimerization among the EGFR family of tyrosine kinase receptors leads to allosteric activation of the kinase domains of the *** other members in the family,the kinase domain of HER3 lacks key amino acid residues for catalytic *** a result,HER3 is suggested to serve as an allosteric activator of other EGFR family members which include EGFR,HER2 and *** study the role of intracellular domains in HER3 dimerization and activation of downstream signaling pathways,we constructed HER3/HER2 chimeric receptors by replacing the HER3 kinase domain(HER3-2-3)or both the kinase domain and the C-terminal tail(HER3-2-2)with the HER2 counterparts and expressed the chimeric receptors in Chinese hamster ovary(CHO)*** over expression of the intact human HER3 transformed CHO cells with oncogenic properties such as AKT/ERK activation and increased proliferation and migration,CHO cells expressing the HER3-2-3 chimeric receptor showed significantly reduced HER3/HER2 dimerization and decreased phosphorylation of both AKT and ERK1/2 in the presence of neuregulin-1(NRG-1).In contrast,CHO cells expressing the HER3-2-2 chimeric receptor resulted in a total loss of downstream AKT activation in response to NRG-1,but maintained partial activation of ERK1/*** results demonstrate that the intracellular domains play a crucial role in HER3’s function as an allosteric activator and its role in downstream signaling.

关键词： HER3 HER2 cell proliferation cell migration PI3K/AKT MAPK/ERK1/2

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Effects of Vapor Pressure and Super-Hydrophobic Nanocomposite Coating on Microelectronics Reliability

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Engineering 2015年第3期1卷 384-390页

作者： xuejun fan Liangbiao Chen C.P.Wong Hsing-Wei Chu G.Q.Zhang Department of Mechanical Engineering Lamar University State Key Laboratory of Solid State Lighting School of Materials Science and Engineering Georgia Tech Delft University of Technology Institute of Semiconductors Chinese Academy of Sciences

Modeling vapor pressure is crucial for studying the moisture reliability of microelectronics, as high vapor pressure can cause device failures in environments with high temperature and humidity. To minimize the impact of vapor pressure, a super-hydrophobic(SH) coating can be applied on the exterior surface of devices in order to prevent moisture penetration. The underlying mechanism of SH coating for enhancing device reliability, however, is still not fully understood. In this paper, we present several existing theories for predicting vapor pressure within microelectronic materials. In addition, we discuss the mechanism and effectiveness of SH coating in preventing water vapor from entering a device, based on experimental results. Two theoretical models, a micro-mechanics-based whole-field vapor pressure model and a convection-diffusion model, are described for predicting vapor pressure. Both methods have been successfully used to explain experimental results on uncoated samples. However, when a device was coated with an SH nanocomposite, weight gain was still observed, likely due to vapor penetration through the SH surface. This phenomenon may cast doubt on the effectiveness of SH coatings in microelectronic devices. Based on current theories and the available experimental results, we conclude that it is necessary to develop a new theory to understand how water vapor penetrates through SH coatings and impacts the materials underneath. Such a theory could greatly improve microelectronics reliability.

关键词： vapor pressure moisture semiconductor reliability microelectromechanical systems (MEMS) superhydrophobic nanocomposite coating

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大庆徐深气田致密气藏间歇开井增产机理

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油气井测试 2020年第5期29卷 14-20页

作者：范学君中国石油大庆油田有限责任公司试油试采分公司黑龙江大庆163412

大庆致密气藏储层物性差,自然测试产能较低,采用大规模多段压裂以实现储量动用和提高单井产能的方法,难以确定本类储层增产原因。对徐家围子致密气区块气藏岩心的微观渗吸置换室内实验进行研究,优化出3种类型储层Ⅰ类储层渗吸效果好,产... 详细信息

大庆致密气藏储层物性差,自然测试产能较低,采用大规模多段压裂以实现储量动用和提高单井产能的方法,难以确定本类储层增产原因。对徐家围子致密气区块气藏岩心的微观渗吸置换室内实验进行研究,优化出3种类型储层Ⅰ类储层渗吸效果好,产能增加明显;Ⅱ类储层渗吸效果一般,产能增加不多;Ⅲ类储层几乎无渗吸,产能无增加;根据储层类别,确定间歇开井时机、优化及完善求产技术。经对Ⅰ类储层Y9井进行间歇开井增产实验,关井16 d渗吸置换,重新开井测气,产量增加83%。该研究结果提高了对徐家围子区域总体认识,指导了区域间歇开井后试气求产,为求产工艺提供了技术指导。

关键词：徐深气田致密气藏储层分类间歇开井试气产能岩心实验

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超声速燃烧数值模拟中复杂化学反应的建模方法

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空气动力学学报 2020年第3期38卷 552-576页

作者：吴坤范学军中国科学院力学研究所高温气体动力学国家重点实验室北京100190 中国科学院大学工程科学学院北京100049

高保真度的数值模拟有助于研究超声速条件下点火、熄火、火焰传播以及稳焰等关键物理-化学过程,推动对冲压发动机中复杂燃烧现象的准确理解与可靠预测。然而,实际发动机中碳氢燃料燃烧导致的广泛时空尺度对湍流燃烧的建模带来了极大的... 详细信息

高保真度的数值模拟有助于研究超声速条件下点火、熄火、火焰传播以及稳焰等关键物理-化学过程,推动对冲压发动机中复杂燃烧现象的准确理解与可靠预测。然而,实际发动机中碳氢燃料燃烧导致的广泛时空尺度对湍流燃烧的建模带来了极大的挑战。为此,必须首先解决超声速燃烧数值模拟中复杂化学反应的高保真建模问题。本文对超声速燃烧模拟中湍流-化学反应相互作用模型、机理简化以及求解加速方法的研究现状进行了总结。以典型燃料燃烧建模为主线,介绍了复杂化学反应的高保真建模方法以及不同化学反应机理在超燃模拟中的适用性及其影响。以反应机理三层次保真度评估体系为基础,进一步明确了简化机理在超燃数值模拟中的优势与不足,阐明了动态自适应化学方法在研究超声速条件下细致燃烧过程的必要性和可行性。

关键词：超声速燃烧碳氢燃料复杂化学反应简化反应机理动态自适应化学

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内盲孔射孔器与管式泵联作技术的研究与应用

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钻采工艺 2006年第1期29卷 62-63页

作者：范学君大庆油田有限责任公司试油试采分公司

介绍了内盲孔射孔器与管式泵联作技术的选泵标准、起爆方式、原理和流程以及内盲孔射孔器的研制。该技术是将油管输送射孔与采油管柱结合起来,使射孔完井与新井下泵一趟管柱完成,在下完抽油杆之后,密封井口,采用油套环空加压引爆射孔枪... 详细信息

介绍了内盲孔射孔器与管式泵联作技术的选泵标准、起爆方式、原理和流程以及内盲孔射孔器的研制。该技术是将油管输送射孔与采油管柱结合起来,使射孔完井与新井下泵一趟管柱完成,在下完抽油杆之后,密封井口,采用油套环空加压引爆射孔枪的方式,射孔后立即启动抽油机,进行采油。该工艺可提高射孔完井效率,又可预防井喷事故发生,减少作业次数和井喷压井所带来的水泥车和压井液费用,同时减轻了工人劳动强度。在大庆油田采油三厂N5-9-B52井的现场应用见到了明显的效果。

关键词：油管输送射孔内盲孔射孔器抽油泵采油

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