Advanced Laser Measurement Technology for Aeroengine Combustor Research and Development

在航空发动机燃烧室的研发过程中,传统的测量手段往往有时无法实施或不能满足精确捕捉流场信息的要求,发展新型、高精度测量以及先进诊断技术势在必行。重点介绍了适用于航空发动机燃烧室测量的先进激光测试技术,并与传统测量方法进行了比较。发动机燃烧室内的流场测量包括速度测量、温度和组分质量分数测量。氢氧根离子标记测速(HTV)方法适用于有化学反应流场的速度测量;而拉曼散射测量技术可以同时测量多种组分的质量分数和温度。利用这些激光测量技术的特点,可以使其在燃烧室的点火、贫油熄火及排放等性能的研究中发挥重要作用。The traditional methods of measurement can't meet the requirements of accurate capturing of the flow field in the development process of the aeroengine combustor.Therefore,the development of high-precision measurement and diagnostic techniques was imperative.The advanced laser diagnostic tools suitabling for aeroengine combustor measurement were introduced importantly and compared with the traditional measurement methods.The flow field measurement in the combustor include the measurement of velocity,temperature,and species concentration.Hydroxyl Tagging Velocimetry(HTV) method is applicable to the velocity measurement in the chemical reaction flow field.Raman scattering technology can measure a variety of species concentrations and temperature simultaneously.The laser diagnostic technique would play an important role in the study of ignition,extinction,and pollutant emission characteristics of the aeroengine combustor.国家自然科学基金(11002125和51106131);中央高校基本科研业务费专项资金(2010121045);教育部留学人员启动资金(J20120104)资

Analysis of the Stretch and Curvature Effects on Premixed Flame Parameters

本文假设简单流场和一步化学反应机理,采用渐进分析法计算了三种特定的拉伸或曲面预混火焰(平面火焰、管式火焰和球面火焰)的火焰速度和火焰温度。火焰速度和火焰温度可以通过两个耦合的非线性代数方程用简单的数值方法求解。基于火焰曲面效果的物理分析,将得到的分析结果拓展到一般曲面火焰,给出了曲面拉伸火焰的火焰速度和火焰温度的曲率效果关联式。通过关联式对平面拉伸火焰的参数进行修正,可以得到任意曲面拉伸火焰的火焰速度和火焰温度。Based on a simple flow assumption and one-step high-activation energy chemistry,the flame speed and flame temperature of three specific stretched and curved premixed flames(the planar flame,the tubular flame,and the spherical flame) are predicted by asymptotic analysis.The expressions for flame speed and flame temperature are two coupled nonlinear equations and they can be solved easily with a simple numerical method.To extend the asymptotic solutions to generally curved flames,correlations on flame speed and flame temperature of the stretched and curved flame are given.With these correlations,the flame speed and flame temperature of any curved and stretched flame can be predicted from information of stretched planar flames.国家自然科学基金资助项目(No.51106131); 中央高校基本科研业务费专项资金资助(No.2010121045

Performance Analysis of Three Kinds of Aero-Engine with Inter-Stage Turbine Burner

为探究级间燃烧室对各种航空发动机的性能影响,利用热力循环原理分别计算了在有无级间燃烧室的情况下涡喷、涡扇和涡轴发动机的性能结果并与实际型号做出对比。通过计算获得了上述三种发动机在加入级间燃烧室后的单位推力和耗油率随飞行马赫数等参数在一定范围内变化的曲线。结果表明加入级间燃烧室后对各种发动机的动力性能提升都在10%以上,个别涡轴发动机可达30%。同时若能将加入级间燃烧室后增加的质量控制在一定范围内,则对于各型发动机均可提高其推重比。In order to investigate the effects of the inter-stage turbine burner( ITB) on aero-engines,the thermodynamic cycle analysis was performed to demonstrate the performance of three kinds of aero-engines with the inter-stage turbine burners.The performance curves for different flight and operation conditions were obtained by calculation.Results show that specific thrust can be improved by at least 10%,and for one turboshaft engine the specific thrust even can be improved by 30%.Based on comparison between the real aero-engine performance and the calculation results,the errors are acceptable and the thrust-weight ratios show the potential capability of ITB application.国家自然科学基金(11002125;51106131); 中央高校基本科研业务费专项资金(2013121019

关于“经济发展方式转变进程中的财税政策”的探讨(笔谈)

转变经济发展方式是当前中国的热门话题,而上海在城市发展中又肩负着率先转变的重要任务,在这一意义和背景下,2010年4月24日由上海金融学院学院主办、上海金融学院公共经济管理学院承办的“《中国城市财政发展报告2009/2010:促进‘两个中心’建设的上海城市财政》首发式暨‘经济发展方式转变进程中的财税政策’论坛“在我校举行。与会专家围绕经济发展方式转变进程中的财税政策的“趋势与目标“、“机遇和挑战“、“实施方略“和“地方实践“等四个专题进行研讨,各抒己见,智慧交锋。现将其真知灼见整理摘要与读者分享,以期待更多学者共同关注当前经济发展方式转变进程中的财税政策

Definition and Properties of Δ P Set valued Function Space

分析了取值于bAnACH空间子集的集值函数的拓扑结构，并在其上建立积分，ΔP度量概念，研究了与逼近问题相关的基本性质.最后给出一个逼近定理：在ΔP度量下取紧凸值的简单集值函数的全体稠密于lPA（Ω，X）.The topological structure of set valued functions with values in subset of Banach space is discussed.The definition and properties of Δ P space related to approximation problem are presented.An approximation theorem is obtained as follows:the family of simple set valued random variables with compactly convex values under Δ P measure is dense in L P A.国家自然科学基

Simulation of no formation in hydrogen-air counterflow diffusion flame

Conference Name:2nd International Conference on Engineering and Technology Innovation 2012, ICETI 2012. Conference Address: Kaohsiung, Taiwan. Time:November 2, 2012 - November 6, 2012.AandF; Tailift Co., Ltd; SPINTECH; Smart Motion Control Co.,Ltd.; FXB Flexible Motion; et alThe combustion of hydrocarbon fuels produces large amounts of carbon dioxide. In order to cope with the challenge of greenhouse effect and global environmental protection. H2, as a cleaner and more energy-burning fuel, is being considered in many of the practical applications of combustion equipments. However, H2 fuel combustion will still produce pollutant NOx. Thus, the study of NOx emission is one of the most important topics in H2 combustion. With the classical counterflow burner, a numerical simulation of NO emission was carried out on the H2 diffusion flames. The stretch effects on flame temperature, NO concentration, and EINO are analyzed; the contribution of different NO generation routs are also quantified and analyzed. The major parameters influencing NO emission are flame temperature, radical concentration, and residence time, the observed relationship between stretch rate and NO emission is explained with the three major parameters. ? (2013) Trans Tech Publications, Switzerland

Analysis of NO formation in counterflow premixed hydrogen-air flame

Conference Name:2nd International Conference on Engineering and Technology Innovation 2012, ICETI 2012. Conference Address: Kaohsiung, Taiwan. Time:November 2, 2012 - November 6, 2012.AandF; Tailift Co., Ltd; SPINTECH; Smart Motion Control Co.,Ltd.; FXB Flexible Motion; et alThough hydrogen fuel reduces the carbon dioxide emission, it still produces NOx. However, gaps exist in the fundamental understanding of hydrogen-air combustion and the NO emission; most previous research has focused on the flames burning with mixture such as H2 mixed with CH4, rather than pure H2 flame. Here, a computational study is presented to investigate the effects of stretch rate on NO formation in counter-flow premixed hydrogen-air flame. The simulations of premixed hydrogen flames were performed with OPPDIF code with UCSD chemical mechanism. Results indicate that the NO formation is affected by three factors: radical concentration, flame temperature, and residence time of reactants. The flame temperature, the reaction rate of NO, and the NO emission index all decrease when the stretch rate increases. Moreover, the formation of NO through thermal mechanism, NNH mechanism, and N2O mechanism are discussed, as well as the percentages of their contribution. ? (2013) Trans Tech Publications, Switzerland

CFD simulation of the fused silica synthesis furnace

Conference Name:2nd International Conference on Engineering and Technology Innovation 2012, ICETI 2012. Conference Address: Kaohsiung, Taiwan. Time:November 2, 2012 - November 6, 2012.AandF; Tailift Co., Ltd; SPINTECH; Smart Motion Control Co.,Ltd.; FXB Flexible Motion; et alThe synthesis process of the fused silica glass uses chemical vapor deposition (CVD) method in a furnace. The synthesis process involves complicated physical-chemical phenomena such as turbulence, combustion, radiation, two-phase flow, and so on. A CFD simulation has been carried out for an industrial furnace and process. The simulation result including temperature and major species concentration then is input to CHEMKIN to calculate the radical equilibrium concentration on the fused silica surface. The trend of the simulated fused silica surface temperature is consistent with the measured refraction index showing that the surface temperature is one of the most important parameters influencing the refractive index uniformity of the fused silica product. ? (2013) Trans Tech Publications, Switzerland

Investigation of the non-equilibrium flow phenomena in the boundary layer of the scramjet engine

Conference Name:2nd International Conference on Engineering and Technology Innovation 2012, ICETI 2012. Conference Address: Kaohsiung, Taiwan. Time:November 2, 2012 - November 6, 2012.AandF; Tailift Co., Ltd; SPINTECH; Smart Motion Control Co.,Ltd.; FXB Flexible Motion; et alHigh-speed and high-temperature are the characteristics of the flow field in scramjet engine; the regular non-slip wall boundary condition requires zero speed at wall; in the same time, the material temperature limit does not allow high wall temperature; therefore the velocity gradient and temperature gradient in the engine boundary layer are huge. If these gradients are too large, the traditional assumption of the local thermal equilibrium in the fluid will fail, the Navier-Stokes equations are no longer valid in the boundary layer. The result of the CFD simulation shows that the local Knudsen number in the engine boundary layer is greater than the critical value with the operating conditions 40Km/Ma8 and 30Km/Ma8; they are non-equilibrium flow and the Navier-Stokes equations fails. Special treatment of the boundary conditions are needed for these kinds of flow. With the operating condition of 20Km/Ma6, the local thermal equilibrium condition is observed and conventional CFD method is valid. ? (2013) Trans Tech Publications, Switzerland

Physical Analysis of Stretch and Curvature Effects on Premixed Flame

湍流燃烧的基本火焰结构是拉伸的曲面涡管;拉伸流场中的管形火焰模拟了湍流燃烧的细微结构。本文对平面预混火焰、拉伸预混火焰和管形拉伸预混火焰进行了质量、能量和组分的守恒分析。通过对比这几种火焰,揭示了火焰拉伸效果是通过优先扩散改变火焰温度和熄火极限;而火焰曲率通过增强或削弱这种优先扩散效果来影响火焰温度,影响的大小和火焰厚度与火焰半径的比值呈正比。The essential structure of turbulent combustion is stretched vortex tube,and this fine flame structure can be resembled by the tubular flame.A physical analysis of the mass,species and energy conservation is carried out on the classic plane prernixed flame,the opposed jet flame and the tubular flame.The comparison between the plane flame and the opposed jet flame reveals that the flame stretch effect results from preferential diffusion and changes prernixed flame temperature and extinction condition.The comparison between the opposed jet flame and the tubular flame shows that flame curvature changes prernixed flame temperature by strengthening or weakening the preferential diffusion,and the strengthening or weakening effect is proportional to the ratio of flame thickness to flame radius.国家自然科学基金资助项目(No.51106131);中央高校基本科研业务费专项资金资助(No.2010121045