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Effect of fuel type on the performance of an aircraft fuel tank oxygen-consuming inerting system

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Chinese Journal of Aeronautics 2021年第3期34卷 82-93页

作者： Xiaotian PENG shiyu feng Chaoyue LI Chen CHEN Weihua LIU Key Laboratory of Aircraft Environment Control and Life Support of MIIT College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

The properties of aviation fuel have a great influence on the performance of oxygenconsuming inerting systems. Based on the establishment of the catalytic inerting process, the flow relationship of each gas component flowing through the catalytic reactor was derived. The mathematical model of the gas concentration in the gas phase of the fuel tank was established based on the mass conservation equation, and the fuel tank model was verified by performing experiments.The results showed that the fuel type exerts a considerably higher influence on the performance of the oxygen-consuming inerting system compared to the corresponding influence on the hollow fiber membrane system, and the relative magnitude of the inerting rates of the four fuel types is RP5 > RP3 > RP6 > JP8. In addition, a higher catalytic efficiency or fuel load rate corresponds to a higher rate of decrease of the oxygen concentration in the gas phase, and the inerting time is inversely proportional to the suction flow rate of the fan. When different fuels are used, the amount of cooling gas and water released from the inerting system are different. Therefore, the influence of fuel type on the system performance should be extensively considered in the future.

关键词： Aviation fuel Catalytic reactions Hollow fiber membrane Inert gas Mathematical model

Measurement of mass diffusion coefficients of O_2 in aviation fuel through digital holographic interferometry

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Chinese Journal of Aeronautics 2019年第5期32卷 1184-1189页

作者： Chaoyue LI Weihua LIU Xiaotian PENG Lei SHAO shiyu feng Key Laboratory of Aircraft Environment Control and Life Support of Ministry of Industry and Information Technology College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics

The experimental apparatus to measure the mass diffusion coefficients of O2 in aviation fuel was constructed based on the digital holographic interferometry method. The theory of mass diffusion coefficient and interference image processing were introduced in detail. The accuracy of the experiment was verified by measuring the mass diffusion coefficient of 0.33 mol/L KCl in aqueous solution at 298.15 K. The mass diffusion coefficients of O_2 in RP3 and RP5 aviation fuels were measured at temperature from 278.15 K to 333.15 K, and the Arrhenius equation was employed to fit the experimental data. In terms of the Stokes-Einstein equation, the viscosities of these two aviation fuels were tested to estimate the correlation among mass diffusion coefficient, viscosity and temperature. A uniform polynomial calculation correlation was proposed to predict the mass diffusion coefficients of O_2 in both RP3 and RP5 aviation fuels, and its accuracy is considerably higher than that of the Stokes-Einstein equation.

关键词： Aviation fuel Diffusion coefficients Digital holographic interferometry Oxygen Viscosity

Theoretical study of ullage washing with mixed inert gas in a non-equilibrium state

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Chinese Journal of Aeronautics 2020年第12期33卷 3167-3175页

作者： shiyu feng Xiaotian PENG Lei SHAO Yan YAN Chen CHEN Weihua LIU Key Laboratory of Aircraft Environment Control and Life Support of MIIT College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China College of Aeronautics Chongqing Jiaotong UniversityChongqing 400074China College of Mechanical and Electrical Engineering Xi'an Polytechnic UniversityXi'an 710000China

The Mixed Inert Gas(MIG)produced by the novel Green On Board Inerting Gas Generation System(GOBIGGS)mainly consists of carbon dioxide,nitrogen and oxygen.Because of the large solubility of carbon dioxide in jet fuel compared with nitrogen,the no gas release or equilibrium model could not be employed any more.In this paper,first,a mathematical model of the ullage washing was set up to predict the variation of the oxygen concentration on ullage and in the fuel,and the gas evolution and dissolution rate were calculated by Fick's second law.Then,an experimental apparatus was constructed to verify the accuracy of the model.Finally,the numerical comparisons of ullage washing using Nitrogen Enriched Air(NEA)and MIG are presented under various flow rates and fuel loads,and the result reveals that the variation of the oxygen concentration on ullage is nearly identical whatever the inert gas is NEA or MIG.However,the variation of the oxygen concentration in the fuel is disparate,and the oxygen concentration decreases rapidly if the inert gas is MIG,especially when the fuel load is low or the flow rate of the inert gas is high.Besides,MIG could suppress the rising trend of the oxygen concentration on ullage when the aircraft ascends if the fuel tank is fully washed into an equilibrium state on ground.

关键词： Inert gas Mixed inert gas Nitrogen enriched air Non-equilibrium Washing

Experimental comparison between aircraft fuel tank inerting processes using NEA and MIG

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Chinese Journal of Aeronautics 2018年第7期31卷 1515-1524页

作者： Lei SHAO Weihua LIU Chaoyue LI shiyu feng Chenchen WANG Jun PAN Key Laboratory of Aircraft Environment Control and Life Support of MIIT Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Aeronautics Chongqing Jiaotong University Chongqing 400074 China Jiangsu Province Key Laboratory of Aerospace Power System Nanjing Engineering Institute of Aircraft Systems Nanjing 210016 China

Fuel tank inerting technologies are able to reduce the fire risk by injection of inert gas into the ullage or fuel, the former called ullage washing and the latter fuel scrubbing. The Green On-Board Inert Gas Generation System（GOBIGGS） is a novel technology based on flameless catalytic combustion, and owning to its simple structure and high inerting efficiency, it has received a lot of attentions. The inert gas in the GOBIGGS is mainly comprised of CO2, N2, and O2（hereinafter, Mixed Inert Gas（MIG））, while that in the On-Board Inert Gas Generation System（OBIGGS）, which is one of the most widely used fuel tank inerting technologies, is NitrogenEnriched Air（NEA）. The solubility of CO2 is nearly 20 times higher than that of N2 in jet fuels,so the inerting capability and performance are definitely disparate if the inert gas is selected as NEA or MIG. An inerting test bench was constructed to compare the inerting capabilities between NEA and MIG. Experimental results reveal that, if ullage washing is adopted, the variations of oxygen concentrations on the ullage and in the fuel are nearly identical no matter the inert gas is NEA or MIG. However, the ullage and dissolved oxygen concentrations of MIG scrubbing are always higher than those of NEA scrubbing.

关键词： Dissolved oxygen Experiment Fuel tanks Inert gases Mixed Inert Gas（MIG） Nitrogen-Enriched Air（NEA） Oxygen

Oxygen concentration variation in ullage influenced by dissolved oxygen evolution

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Chinese Journal of Aeronautics 2020年第7期33卷 1919-1928页

作者： shiyu feng Chaoyue LI Xiaotian PENG Tao WEN Yan YAN Rongjie JIANG Weihua LIU Key Laboratory of Aircraft Environment Control and Life Support of MIIT College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Building Services Engineering Hong Kong Polytechnic UniversityHong KongChina College of Mechanical and Electrical Engineering Xi'an Polytechnic UniversityXi'an 710000China

To determine the oxygen concentration variation in ullage that results from dissolved oxygen evolution in an inert aircraft fuel tank,the CFD method with a mass transfer source is applied in the present study.An experimental system is also designed to evaluate the accuracy of the CFD simulations.The dissolved oxygen evolution is simulated under different conditions of fuel load and initial oxygen concentration in ullage of an inert fuel tank with stimulations of heating and pressure decrease.The increase in the oxygen concentration in ullage ranges from 0.82%to 5.92%upon stimulation of heating and from 0.735%to 12.36%upon stimulation of a pressure decrease for an inert ullage in the simulations.The heating accelerates the release of the dissolved oxygen from the fuel by increasing the mass transfer rate in the mass transfer source and decreasing the pressure,thereby accelerating the dissolved oxygen evolution by increasing the concentration difference between the gas and the fuel.The time constant that represents the oxygen evolution rate is independent of the initial oxygen concentration in ullage of an inert tank but depends closely on the fuel load,temperature and pressure.The time constant can be fitted using a polynomial equation relating the fuel load to temperature in the heating stimulation with an accuracy of 4.77%.Upon stimulation of a pressure decrease,the time constant can be expressed in terms of the fuel load and the pressure,with an accuracy of 5.02%.

关键词： Computational Fluid Dynamics(CFD) Dissolved oxygen evolution Mass transfer Stimulation Time constant Volume of fluid

Enhance the performance of polymer solar cells via extension of the flanking end groups of fused ring acceptors

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Science China Chemistry 2018年第10期61卷 1320-1327页

作者： shiyu feng Danyang Ma Liangliang Wu Yahui Liu Cai'e Zhang Xinjun Xu Xuebo Chen Shouke Yan Zhishan Bo Key Laboratory of Energy Conversion and Storage Materials College of Chemistry Key Laboratory of Theoretical and Computational Photochemistry Ministry of Education Beijing Normal University State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology

Two new fused ring electron acceptors(FREAs)IDT-IC-T and IDT-IC-B with thienyl or phenyl substituents at the terminal INCN unit are synthesized.Theoretical calculations indicate that the two acceptors dominantly favor an intermolecularπ-πstacking between the flanking terminal groups.The twist angle between the aryl substituent and INCN unit has a significant influence on theπ-πstacking distance of terminal unit.IDT-IC-T with a smaller twist angle has a shorterπ-πstacking distance than that of IDT-IC-B with a larger twist angle.In addition,extending the conjugation also affects the blend film morphology.IDT-IC-T and IDT-IC-B based photoactive films show appropriate nanoscale phase separations;whereas,blend films based on the parent compound IDT-IC show large-size acceptor domains.As expected,PBDB-T:IDT-IC-T blend films show higher and more balanced electron and hole mobilities.Moreover,these two acceptors present a good charge-transport connectivity arising from the extended conjugation and the increased intermolecular overlapping.Ultimately,IDT-IC-T demonstrates the highest electron mobility(1.47×10^(-4)cm^2V^(-1)s^(-1))and the best power conversion efficiency(PCE)of 9.43%.As for IDT-IC,which only shows an electron mobility of 7.33×10^(-5)cm^2V^(-1)s^(-1)and a PCE of 5.82%.These findings provide a facile and effective way to improve the photovoltaic performance.

关键词：太阳能电池戒指熔化聚合物表演苯基取代芳基取代扭曲角

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大型机载油箱电位分布与静电击穿仿真研究

南京航空航天大学学报 2024年第2期56卷 358-363页

作者：刘豪正刘祎高经诚郭晨阳范菊莉冯诗愚南京航空航天大学航空学院南京210016 航空工业成都飞机工业(集团)有限责任公司成都610073 航空工业金城南京机电液压工程研究中心南京211106

低导电性的航空燃油在流经管路阀门等结构时会带有一定量的静电荷,这些静电荷最终会汇入燃油油箱。对于载油量较大的不规则飞机油箱,静电规律的数值计算与试验测量均不便展开。本文采用数值仿真软件COMSOL Multiphysics对油箱在充油过... 详细信息

低导电性的航空燃油在流经管路阀门等结构时会带有一定量的静电荷,这些静电荷最终会汇入燃油油箱。对于载油量较大的不规则飞机油箱,静电规律的数值计算与试验测量均不便展开。本文采用数值仿真软件COMSOL Multiphysics对油箱在充油过程中静电电位分布、静电放电电位和静电打火能进行仿真计算,并且对油位高度以及初始电荷密度对油箱静电放电及打火可能性的影响进行研究。通过计算充油过程中产生静电放电所需的最小击穿电压和产生静电带有的能量,对油箱内电位是否会引起静电击穿和引燃油箱内混合气体进行分析,为静电引起的油箱爆炸的风险评估提供了一种新思路。

关键词：人机与环境工程静电放电帕邢定律飞机油箱航空安全

Numerical Analysis on Solidification Behavior of Graphene Nanoplatelet Based Nanofluid in Cold Storage Cavity

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Journal of Thermal Science 2022年第4期31卷 1180-1193页

作者： CHEN Chen feng shiyu PENG Hao PENG Xiaotian LIU Weihua College ofAerospace Engineering Nanjing University ofAeronautics and Astronautics Nanjing 210016China Institute of Thermal Engineering Shanghai Maritime UniversityShanghai 201306China

Addition of graphene nanoplatelet(GNP)into water is a promising method for improving cold storage system performance,and its application requires comprehensive understanding of solidification behavior of GNP-water nanofluid.In the present study,the influences of GNP mass concentration,cold storage cavity size and shape on solid-liquid interface evolution,temperature distribution,streamline profile as well as solidification rate are numerically analyzed.The enthalpy-porosity technique is adopted to track solid-liquid interface.The results show that the enhancement effect of GNPs on solidification is mainly reflected in the final stage in which heat conduction is predominant;the solidification occurs at the bottom of cavity in the early stage,and the solid-liquid interface is similar to the shape of cavity itself and then tends to be circular in the middle and final stages respectively;the reduction degree of solidification time reaches 30.1%at GNP mass concentration of 1.2 wt%under present simulation conditions;decreasing cavity size and adopting triangular cavity are beneficial for promoting the solidification,but they will suppress the enhancement effect of GNPs on solidification.

关键词： cavity shape graphene nanofluid phase change material solidification

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工程管理中的数据信息处理分析

电子技术（上海） 2024年第2期53卷 304-305页

作者：冯仕煜陆范毅国网兴化市供电公司江苏225700

阐述信息技术在工程管理数据中的应用特点,包括工程数据管理、自动化控制、工程计算、信息人才培训。提出提升工程管理数据信息技术处理效果的策略。

关键词：工程管理信息技术数据处理