空调列车室内流场的数值模拟

运用 K-ε紊流模型对 K2 5型空调列车 (硬座车 )室内气流组织 ,主要是速度场进行了数值模拟 .采用有限单元法和交错网格 ,将送风气流与车厢形状及障碍物作为一体考虑 ,研究了送风方式和送风速度对空调列车室内流场的影响 .结果表明 ,送风方式对空调列车室内流场影响较大 ,而送风速度在 2～ 3m/ s范围内 ,对空调列车室内流场影响较小 .研究结果对空调列车室内气流组织优化设计及舒适性评价提供了依据 .图 9,表 1,参 8     

应用辐射供暖的列车车厢气流组织研究

列车的气流组织对室内人员的舒适性有重要影响.为了研究辐射供暖和空调送风联合作用时适宜的室内气流组织形式,以某动车车厢为研究对象,使用Airpak软件进行了数值模拟,给出了不同方案下车厢内的速度场、温度场的分布情况.研究了送风风速、辐射板温度、送风温度等对车厢气流组织的影响,并通过评价指标的对比分析,给出了适宜的辐射供暖...     

青藏线空调列车室内气流组织的沿线变化数值分析

以青藏线25T型空调列车为研究对象,为获得运行过程中车外环境对车内气流组织的影响特征,采用湍流Realizable k-ε模型对列车途经各主要站点时车内流场和温度场进行了数值分析。结果表明：太阳辐射对车内温度场的影响显著,送风参数随车外环境参数的变化而变化的空调模式对于确保高原列车室内舒适性意义重大。不同送风工况下的车内温度场和速度场之间的耦合作用导致车内不同位置的舒适性有所差别。同时,讨论了不同车外环境条件下各送风工况之间的转换问题,对现有空调系统的功能改进提出了更高的要求。     

地下高大厂房空调送风的数值模拟

对地下高大厂房改变空调送风量，改变风口数量、风口布置方式、送风风速的室内气流进行模拟计算，得出了不同送风方案工作区的平均温度、速度及相应的标准差，最后分析了对工作区温度场和速度场的影响因素并得到了最优的设计方案，这种数值模拟方法对地下高大厂房空调模型试验及其空调系统优化设计有重要指导意义。     

空调客车室内三维紊流流动与传热数值研究

空调车空内空气的速度场,温度场研究是空调车室内气流组织设计及车室内舒适环境评价与研究的基础。空调客车运行环境恶劣,太阳辐射作用及复杂的车室内部结构等直接影响客车室内的温度场与空气速度场分布。     

浅谈送风速度对制冷效果的影响

气流组织是控制、安排空调区域内空气流动过程的技术,其优劣直接影响室内的空调效果,而室内气流组织与送风速度的大小有直接关系。本文就广州某大厦的高大空间大堂空调使用后达不到效果,简单分析其原因,由于送风速度的不足,导致气流在人员活动区上方循环,冷气无法到达活动区,制冷效果差。通过提高送风速度,解决问题。     

基于Airpak的夏季空调室内热环境数值模拟研究

基于Airpak软件,选用室内零方程湍流模型对一夏季空调办公室内热环境进行了三维数值模拟,得到室内气流组织下的流场、温度场分布.采用PMV-PPD与空气龄指标对室内人员热舒适性及空气品质进行了评价,并通过测试室内温度、风速参数,验证了数值模拟结果的准确性.研究表明:对于分体式空调器房间,气流组织分布与空调器的安装位置、室内设备的摆设以及室内人员的分布有关,不同的气流组织将形成不同速度场和温度场.室内温度场分布在水平方向比较均匀,在垂直方向产生明显的温度分层;室内零方程湍流模型能准确快速模拟空调通风房间气流组织分布,PMV-PPD与空气龄指标能对人体热舒适及空气品质进行数值预测与评价,为房间空调器送风温度、速度参数的合理设定提供参考依据;热环境数值模拟对空调系统的气流组织设计、运行调节具有重要的指导意义.     

室内环境参数对室外气象参数瞬时变化的动态响应研究

为研究空调房间室内环境参数对室外气象参数瞬时变化的动态响应,采用CFD中的标准k-ε模型对兰州地区某办公室在考虑非稳定传热情况下的室内气流组织和污染物浓度场进行数值分析,获得了顶送风/下回风和侧送风/下回风两种通风模式下室内流场、温度场及污染物浓度场的分布。结果表明:不同时刻的太阳辐射通过激励室内自然对流换热过程对室内污染物的空间分布及迁移特性产生了显著影响。同一送风模式下,16:00时室内的污染物浓度较8:00时均匀,而8:00时的污染物浓度平均水平较高;在同一送风参数下,采用顶送风方式时更有利于降低室内污染物浓度。     

铁路空调硬卧客车室内气流组织的数值模拟

采用双方程三维紊流模型，对YW250G铁路空调硬卧客车室内气流的温度场和速度场进行模拟，根据计算结果分析了室内气流组织的平均空气龄，为铁路空调客车空调气流组织的设计提供了依据。     

工位送风口形式对办公室内气流分布的影响研究

工位送风是一种将新风直接送到工作岗位的送风方式,与传统空调相比,工位送风大幅提高了送风有效性.为分析办公室内适宜采用的工位送风口形式,建立了办公室内应用工位送风系统的物理模型,对采用不同形式工位送风口送风时的办公室内气流分布进行了数值模拟,对比分析了办公室内温度、速度、PMV和污染物质量浓度分布,研究结果表明,采用孔径...     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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     

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