Computational fluid dynamics simulation of the wind flow over an airport terminal building

Turbulence in the wake generated by wind flow over buildings or obstacles may produce complex flow patterns in downstream areas. Examples include the recirculating flow and wind deficit areas behind an airport terminal building and their potential impacts on the aircraft landing on nearby runways. A computational fluid dynamics （CFD） simulation of the wind flow over an airport terminal building was performed in this study of the effect of the building wake on landing aircraft. Under normal meteorological conditions, the studied airport terminal building causes limited effects on landing aircraft because most of the aircraft have already landed before entering the turbulent wake region. By simulating the approach of a tropical cyclone, additional CFD sensitivity tests were performed to study the impacts of building wake under extreme meteorological conditions. It was found that, in a narrow range of prevalent wind directions with wind speeds larger than a certain threshold value, a substantial drop in wind speed （〉3.6 m/s） along the glide path of aircraft was observed in the building wake. Our CFD results also showed that under the most critical situation, a drop in wind speed as large as 6.4 m/s occurred right at the touchdown point of landing aircraft on the runway, an effect which may have a significant impact on aircraft operations. This study indicated that a comprehensive analysis of the potential impacts of building wake on aircraft operations should be carried out for airport terminals and associated buildings in airfields to ensure safe aviation operation under all meteorological conditions and to facilitate implementation of precautionary measures.     

基于TIN地形数据的地形匹配算法的研究

介绍了DTM(Digtial Terrain Models)的结构,并对TIN(Triangulation of Irregular Network)地形数据进行了分析,提出了一种新的基于TIN地形数据的地形匹配跟踪算法.     

Reliability assessment of building structures under typhoon calamity

Typhoon is one of the most destructive natural calamities. Statistical data on 1949–1990 typhoons in China were used to analyze the frequency and strength of the typhoons, the relation between them and the average global ground temperature. The probability distribution of wind speed and the load of low buildings were obtained respectively on the basis of statistical data on the No. 9015 and No. 9711 typhoon. The finite element method and experimental comparison were used to obtained the probability distribution of lateral force resistance of a three-story brick-concrete building. Finally, the reliability indexes of this kind of building under No. 9015 and No. 9711 typhoon; and some valuable suggestions are given. Project (59895410) supported by NSFC     

复杂体型钢筋混凝土高层建筑的推覆分析方法和应用

In this paper, push-over analysis for tall concrete structures was made and a corresponding computer program was given.Several kinds of elements in the program were considered to meet the demand of tall buildings with complex structural type. These elements included beam-column element for beams and columns, single slice wall element and three vertical line element for walls, and tube-wall element for tubes. Computational example for verifying the models indicates that the result obtained by this method is identical with a well-known test result and the program can be used to search for the full process of structural reaction, even the softening stage of the structure. With this push-over analysis method, an actual tall building with complex structural type was analyzed, and the result has been put into practice of the structural design of the building.     

Safety analysis of optimal outriggers location in high-rise building structures

INTRODUCTION Outriggers location has direct influence on the efficiency of the horizontal deflection control in high-rise building structures. An appropriate outrigger location will be more efficient in minimizing the horizontal deflection and reducing the restraining moments mutation. As a result, the safety of a struc-ture subjected to lateral load is guaranteed to be better. Presently, the so-called optimal location of out-riggers is derived from the principle of minimum ultimate disp…     

建筑结构地震响应混沌特性及影响因素分析

采用混沌时间序列分析方法分别对以经典混沌信号和地震动为激励的结构响应进行混沌特性分析,从关联维数、Kolmogorov熵及最大Lyapunov指数等定量指标的角度,考察结构自振周期、地震动的类型和幅值等因素对结构地震响应的非线性特性的影响。研究结果表明:在经典混沌信号和地震动作用下,经过结构的放大和滤波作用,结构加速度响应仍然保留了混沌特性,且通过混沌参数的变化程度能够判断结构是否进入弹塑性状态。结构自振周期为结构加速度响应的混沌特性的主要影响因素;幅值对经典混沌信号作用结构下加速度响应的混沌特性影响较为显著;而地震动的类型、幅值等因素对地震动作用下响应的混沌特性影响更为显著。     

对语言实验室开放的研究

语言实验室在外语学习中发挥着重要作用。本文通过语言实验室开放的实践,分析了开放语言实验室的意义、理论基础、实施和管理,以期加强这方面的交流,更好地为学生服务。     

Numerical study on effects of door-opening on airflow patterns and dynamic cross-contamination in an ISO class 5 operating room

The contamination diffusion to the operating room when the door is open was simulated with a computational fluid dynamic (CFD) method,to give the extent of the contamination diffusion.The influence of the door-opening procedure was ignored since the door of the operating room is normally a sliding one.The flow field in the case of the 16 s course of opening the door was simulated.The simulated and the experimental results demonstrate that the extent of the contamination diffusion is around 1.5 m when there is no temperature difference between indoor and outdoor,and there is hardly any contamination diffusion when the temperature difference is 1 ℃.It can be concluded that the positive pressure difference in the operating room lost its function in preventing the contamination when the door is open.That the temperature of corridor is lower than that of operating room contributes to contamination control.Keeping 1 ℃ temperature difference between corridor and operating room and increasing positive pressure and air flow are suggested.It is more secure to set up an anteroom if persons come in or out of the operation room at the course of surgery.     

Optimization of time-delayed feedback control of seismically excited building structures

An optimization method for time-delayed feedback control of partially observable linear building structures subjected to seismic excitation is proposed. A time-delayed control problem of partially observable linear building structure under horizontal ground acceleration excitation is formulated and converted into that of completely observable linear structure by using separation principle. The time-delayed control forces are approximately expressed in terms of control forces without time delay. The control system is then governed by Itoe stochastic differential equations for the conditional means of system states and then transformed into those for the conditional means of modal energies by using the stochastic averaging method for quasi-Hamiltonian systems. The control law is assumed to be modal velocity feedback control with time delay and the unknown control gains are determined by the modal performance indices. A three-storey building structure is taken as example to illustrate the proposal method and the numerical results are confirmed by using Monte Carlo simulation.     

横流冲击射流涡旋结构的实验和数值研究

The objective of this dissertationis toinvestigate thei mpingingjet under the influence of crossflow.It hasbeen known that there exist jet shear layer ,i mpinge-ment on the bottom wall ,interactions between the in-duced wall jet and the ambient crossflowin near field .There are fewintensive studies of the i mpinging jet incrossflowat home and abroad due to the complexitiesof flow, such as the formation and evolution of thevortical structures ,interactions among vortices , whileresearches on th…     

数据中心列间空调气流组织分析与优化

以小型数据服务机房为研究对象,对机房使用列间空调后的气流组织进行了分析。利用CFD(流体动力学)软件对房间内的气体流动情况进行模拟,绘制温度、矢量风速计算云图,对比了冷通道封闭前后房间温度场、风场的变化,分析封闭前后室内换热情况。研究发现,冷通道封闭后离地0.5、1.5m处平均温度较封闭前平均温度下降2℃左右,机柜顶面下降1℃左右。封闭冷通道能够优化气流组织,有效避免气流短路,机房内局部热点消失,无效换热减少。     

大连建设创新型城市的思考

贯彻落实党的十六届五中全会和全国科技大会精神,提高大连自主创新能力,向建设创新型城市目标迈进,需要我们立足于大连实际,适应社会主义市场经济的需求,实施自主创新发展战略,构建有利于自主创新的体制机制,培养高水平创新人才,大力发展创新文化。     

枢纽机场中转水平度量评价研究

为了全面分析我国主要机场的中转能力,准确把握我国枢纽机场建设中存在的问题,从机场航线网络的布局和航班时刻编排的角度,构建了中转水平度量模型。从模型可得到枢纽机场所能提供的中转机会和中转质量,利用模型对我国和美国的主要枢纽机场进行实证研究。结果显示,在吞吐量相当的情况下,中美两国国内枢纽机场的中转水平均高于其他类型的枢纽,美国主要枢纽机场的中转水平普遍高于我国机场。中转水平度量模型为我国枢纽机场评价指标体系的构建奠定了基础,对完善航线网络的结构和航班时刻的编排,提高中转水平等具有指导意义。     

Methods for progressive collapse analysis of building structures under blast and impact loads

Progressive collapse of building structures under blast and impact loads has attracted great attention all over the world. Progressive collapse analysis is essential for an economic and safe design of building structures against progressive collapse to blast and impact loads. Because of the catastrophic nature of progressive collapse and the potentially high cost of constructing or retrofitting buildings to resist it, it is imperative that the progressive collapse analysis methods be reliable. For engineers; their methodology to carry out progressive collapse evaluation need not only be accurate and concise, but also be easily used and works fast. Thus, many researchers have been spending lots of effort in developing reliable, efficient and straightforward progressive collapse analysis methods recently. In the present paper, current progressive collapse analysis methods available in the literature are reviewed. Their suitability, applicability and reliability are discussed. Our recent proposed new method for progressive collapse analysis of reinforced concrete frames under blast loads is also introduced.     

Mapping out the ICT integration terrain in the school context: identifying the challenges in an innovative project

This article discusses the research findings from the start-up phase of an innovative information and communication technology (ICT) project focused on ICT integration as a complex process involving many factors such as leadership, school readiness and organisational culture. Known locally as Hermes, the project's core objective was to provide an improved and ‘trouble-free’ ICT infrastructure for schools using thin client technology and a wireless broadband network, which would be managed centrally rather than locally. It was anticipated that this solution would help remove the barriers associated with ICT integration caused by technical issues. Based on an in-depth study of innovation adoption in eight schools involving a survey (n=119 teachers) and interviews (n=60 teachers), the study portrays a picture of the ICT integration patterns prior to and during the Hermes intervention in terms of schools' ICT readiness, leadership and vision. This small scale study can help us understand first- and second-order barriers to ICT integration in schools. In particular, this study informs us about the ecology of schools and ICT-based innovation, innovation scalability and contributes to a critical study of educational technology via a context-rich account of how educational technology is actually being mediated, rather than an idealised account of how technology could be used.     

建设生态福州的若干思考

生态城市，归根结底就是人与自然的高度和谐统一。坚持人与自然和谐的价值观导向，处理好建设、保护与发展的关系，通过发展循环经济，建设整个城市生态系统，一个生态福州是指日可望的。     

浅议创新型实验技术队伍建设

从培养创新人才出发,根据创新型实验技术队伍建设的必要性,迫切性和现行实验技术队伍存在的主要问题,提出了从根源上解决问题的具体措施。     

创建节约型高职院校后勤管理新模式

创建节约型高职院校后勤管理模式具有现实意义。高职院校后勤管理工作要坚持＂细化＂、＂务实＂、＂以人为本＂的基本原则,树立科学理财观,推进后勤管理集约化;建设节约型后勤文化,提升后勤管理者人文素养;树立＂以人为本＂理念,稳步实践节约型后勤管理,以促进节约型高职校园的建设。     

基于Adams-Matlab联合仿真的车辆地面相互作用研究(英文)

根据多体动力学在Adams环境中建立了某款工程车辆的模型,以汽车地面力学中Bekker承压模型和Jo-nasi剪切模型为基础建立了刚性轮和弹性轮模型以模拟轮胎地面接触,并将轮胎地面接触模型用S函数描述,以提高仿真运行速度和计算精度.最后借助Adams-Matlab联合仿真工具,对车辆与松软地面相互作用问题进行了仿真计算,研究了地面特性对车辆行驶平顺性的影响.仿真计算结果表明,同车辆行驶速度、路面不平度和载荷一样,地面土壤力学特性对车辆行驶平顺性也有重要影响.该联合仿真模型能将地面变形因素考虑到车辆平顺性分析中,为非公路车辆悬架优化设计提供了思路和研究基础.     

Forming shared inquiry structures to support knowledge building in a grade 5 community

This study explores the reflective processes by which a grade 5 science community co-constructed shared inquiry structures to focus and guide its inquiry about human body systems over a school year supported by a collaborative online environment. The co-constructed structures included a list of collective wondering areas as the shared focus of inquiry and models of the inquiry process in the form of “research cycle.” Qualitative analyses of field notes, classroom videos, student notebooks and interviews elaborate the evolution of the inquiry areas and the “research cycle” model as well as students’ adaptive use of the structures to guide deeper inquiry. Content analyses of students’ individual research questions and collaborative online discourse indicate that students used the structures to develop more advanced inquiry and make productive contributions. The results contribute to elaborating a reflective structuration approach to co-organizing and sustaining long-term, open-ended inquiry in knowledge building communities.