一种拓宽微型单管燃烧室流量范围的调节装置

为了能够拓宽微型单管燃烧室稳定燃烧的流量范围,设计了一种调节装置.利用CFD软件Fluent对微型单管燃烧室的内部冷态流场进行数值模拟,得到微型单管燃烧室主要结构参数对内部流场形态的影响规律并确定了其主要结构参数.通过冷态数值模拟,得到了调节装置对微型单管燃烧室内部流场的调节作用;通过试验研究,证明所设计的调节装置能够实现对单管燃烧室的稳定燃烧流量进行调节,从而扩大了该燃烧室的稳定燃烧流量范围.     

电控单缸柴油机燃烧室设计与实验研究

为了满足发动机动力性、经济性和排放的要求,设计与进气系统和燃油喷射系统相匹配的燃烧室构型至关重要。采用数值模拟和实验验证相结合的方法,对电控单缸柴油机的燃烧室进行设计和优化。参考基准机型的主要结构参数,完成燃烧室结构设计,采用Euler-Lagrange联合仿真法对发动机标定点和扭矩点的性能进行计算,并与实验结果对比;对燃烧室结构进行参数化建模,研究标定点和扭矩点工况下燃烧室缩口比、燃烧室深度、燃烧室内径3个关键结构参数对发动机耗油率和排放的影响。结果表明:EulerLagrange联合仿真法满足燃烧室设计要求;在进气系统和燃油喷射系统确定的情况下,燃烧室的3个关键结构参数对发动机性能有显著影响。     

微型燃气涡轮发动机喷嘴雾化性能研究

针对微型燃气涡轮发动机喷嘴的雾化对燃烧室火焰稳定性、温度分布和燃烧效率的影响.对某微型燃气涡轮发动机喷嘴的雾化情况进行了数值模拟,并利用平面粒子图像测速仪(PIV)对雾化流场进行了测试,并与数值模拟结果进行相互验证.结果表明,实验结果与数值模拟结果符合较好.该研究为微型燃气涡轮发动机的喷嘴、燃烧室设计及燃烧数值计算提供理论及试验基础.     

硅微型机械振动陀螺仪的计算机辅助设计

建立了硅微型机械振动陀螺仪的优化模型,确定其结构参数的目标函数和约束条件,采用优化方法对结构参数进行优化计算.以AutoCAD为支撑软件,采用ActiveX Automation技术对AutoCAD进行二次开发,建立了硅微型机械振动陀螺仪的计算机辅助设计系统(GYROCAD).该系统可以根据陀螺仪的性能指标等确定陀螺仪的最优结构参数,设计实例表明,由该系统设计的硅微型机械振动陀螺仪的灵敏度得到了明显的提高.     

用高精度迎风格式模拟潜入式喷管流场

为了研究固体火箭发动机潜入式喷管内部工质的流动特性 ,首先采用改进的 L U-SGS方法和高精度、高分辨率的 MUSCL TVD格式数值模拟了 JPL美国喷气推进实验室喷管 ,数值模拟结果和实验结果吻合得很好。证明了这种方法可以准确地捕捉到流场中可能出现的各种复杂流动。用同样的数值计算方法模拟了固体火箭发动机潜入式喷管 3个时刻的准三维流场 ,对复杂的计算区域做了分区处理 ,为复杂的边界条件做了简化处理模型。分析了燃烧室潜入段处涡的形成和发展过程以及入口湍流度对喷管的气动参数的影响 ,为设计高性能的固体火箭发动机提供了有益的帮助     

微型涡喷发动机燃烧室优化设计

由于供油方式和来流条件不同,现有微型涡喷发动机燃烧室直接参照大型航空发动机燃烧室设计,存在明显"尺度效应",导致微型涡喷发动机燃烧室性能较差,主要表现为燃烧室壁面温度过高、燃烧稳定性差和出口温度分布均匀性差.该文采用ANSYS和CFX数值模拟分析了现有某型号微型涡喷发动机燃烧室内的空气流动和燃烧过程,并通过冷态实验验证...     

二维火箭发动机燃烧室化学反应粘性流场的数值模拟

用时间相关法的显式格式 ,结合两方程的k -ε湍流模型求解氢氧发动机燃烧室中的粘性化学反应流场 ,化学反应采用 9种组分、5个主要反应的有限速率的化学反应模型 ,得到了流动参数与组分的质量分数在燃烧室中的分布情况。其结果同理论分析的结果相一致 ,从而验证了用数值模拟方法取代部分实际试验的可行性及可信性     

联焰稳流器对驻涡燃烧室性能的影响分析

为考察联焰稳流器对驻涡燃烧室的流场和性能的影响,应用高端数字样机系统进行了设计和数值计算。在典型驻涡燃烧室三维模型上添加了联焰稳流器,分析了2个燃烧室模型在不同进口马赫数条件下的冷态流场结构和总压损失。选取进口马赫数为0.2的工况,对2个模型的燃烧流场进行对比,分析了联焰稳流器对燃烧室性能的影响。结果表明:驻涡燃烧室的NOx排放低于普通构型燃烧室;添加联焰稳流器后,驻涡区能更好地实现与主流区的物质交换,避免因主流速度过快,切断驻涡区与主流区的能量传递;燃烧效率从97%提高至99%,出口温度分布系数从0.92降为0.49;2个模型各冷态工况的总压损失也分别增加2%~12%。     

注蒸汽燃气轮机燃烧室内部流场特性的三维数值模拟

介绍了适于注蒸汽燃气轮机（ＳＴＩＧ）燃烧室流场模拟的大湿度燃烧计算模型,对三维流场计算的数值方法及特殊处理进行了说明,并采用有关文献中的实验数据对燃烧计算程序进行校验,最后对某实验用注蒸汽燃烧室的内部流场进行数值模拟,计算结果表明,文中采用的数学模型及计算程序是可信的,大湿度燃烧室流场的三维模拟可更贴近实际地描述燃烧室内部各物理量,尤其是水蒸汽质量分数的分布情况,壁面射入的蒸汽流使中心回流区及高温     

涡扇发动机涡轮后内外流场及壁面温度场数值研究

基于航空发动机红外辐射特性数值仿真的需求,建立涡扇发动机部件的几何模型,利用数值模拟结合实验验证的方法对涡轮后内外流场及壁面温度场进行研究。比较模型与常用模型的计算结果可得出:受发动机部件几何型面及安装特点影响,发动机喷管前的内部流场及壁面温度场都成明显的周期分布。壁面温度分布形态主要受波瓣混合器影响,但加力部件使高温区域面积减小,使壁面温度分布更快进入轴对称状态。加力部件降低了发动机内部的速度分布均匀度;同时也使截面参数分布更均匀。当采用环形混合器时,流向截面上流向涡尺寸大、强度小、温度掺混情况差。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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