Error Analysis of Liquid Holdup Measurement in Gas-Liquid Annular Flow Through Circular Pipes Using High-Speed Camera Method

Accurate measurement of gas-liquid phase fraction is essential for the proper modelling of the pressure drop, heat transfer coefficient, mass transfer rate and interfacial area in two-phase flows. In this paper, taking the issue of optical distortion into account, an analytical model was proposed to estimate and correct the liquid holdup in gas-liquid annular flow through a circular pipe using high-speed camera method. The error in the liquid holdup measurement generated from different refractive indices among transparent circular pipe, liquid film and air core was firstly theoretically analyzed based on the geometric optics. Experimental tests were then carried out to identify the difference as well as to validate the proposed model. Results indicated that the prediction of the liquid holdup has a good performance with the experimental data (i.e., mean relative error is 4.1%) and the measured liquid holdup is larger than the real one. It was found that the measured liquid holdup is larger than the real one. Generally, when the real liquid holdup gets smaller, the discrepancy between the measured liquid holdup by image and the real liquid holdup becomes more significant. Thus, after measuring the liquid holdup from the images, the value of the measured liquid holdup must be corrected by the present model in order to obtain the real liquid holdup.     

柴油/甲醇组合燃烧在增压柴油机上的应用

在4102增压柴油机上采用柴油/甲醇组合燃烧方式(在柴油机的一部分工况采用现有的扩散燃烧方式,另一部分工况采用柴油引燃醇燃料均质混合气的组合燃烧方式)进行试验;试验结果表明,采用组合燃烧后柴油机的NOx排放和燃料的消耗率较原机有显著减少。     

基于手机信令数据的旅游交通出行网络特性

为了合理开展面向区域城市群的旅游交通协同规划,以江浙沪皖地区的18个主要旅游城市为例,基于入境旅游者的手机信令数据构建了城市间的旅游出行网络,并运用节点结构指标和网络结构指标对其进行评价,定量分析了入境旅游客流在城市间的空间分布特征。研究结果表明：上海、杭州和南京等城市在区域旅游交通规划中起着重要的引领作用;连云港、徐州和盐城等城市需加强与核心城市之间构建高效的出行路径;城际间便捷的综合交通出行网络对于提升区域旅游的整体竞争力发挥着重要作用。     

舰船编队可靠性建模评估方法研究

针对舰船编队网络,分析了其网络通讯的特点,归纳出影响舰船编队网络可靠性的12个因素,给出了各种因素的重要度。建立了评价舰船编队网络可靠性模型,并且应用AHP法评价了舰船编队网络可靠性,确定了每种影响因素的比重,分析出影响舰船编队网络可靠性的2个关键因素。证明了应用AHP法进行网络可靠性评价的可行性。     

多媒体网络化的大学英语教学管理模式探索

建构主义学习理论改变了传统的学习理论,提出了新的学习观、师生观和学习环境观.多媒体网络化的大学英语教学管理模式真正契合了建构主义学习理论,要求教师注重建立监督与激励机制.实验表明,多媒体网络化的大学英语教学管理模式优于传统的教学管理模式.     

多雷达与ADS数据融合的可变周期更新算法

为提高空中交通管制系统的整体监视精度,在研究自动相关监视(automatic dependentsurveillance简称ADS)信息与雷达监视信息构成和特征差异的基础上,通过建立ADS目标与雷达目标之间的数据关联映射关系,构造了一个将ADS数据与多雷达数据融合处理的过程模型,提出了基于ADS报告周期调整ADS航迹与雷达航迹融合权重因子的可变周期更新算法。应用结果表明更新算法实现了两类信息的深度融合和对有效信息的综合利用,既保证了当ADS报告更新率较高时ATC监视的整体精度,又提高了ADS报告更新率较低时目标航迹的连续性,降低雷达测量误差对系统监视精度的影响,是一种用于空中交通管制系统监视数据处理的有效方法。     

高盐高湿环境电务轨旁器材腐蚀寿命评估方法研究

在高盐高湿环境的海底隧道内,轨旁电务器材腐蚀情况较为严重,对信号传输和行车安全带来极大的隐患.通过对高盐高湿隧道环境调研,量化隧道内环境指标,结合隧道环境评估结果制定腐蚀加速实验的环境谱,在实验室进行加速盐雾试验,选取实验样品的失重比表征腐蚀程度,结合腐蚀动力学评价方法进行金属腐蚀寿命评估方法研究.为海底隧道轨旁金属器...     

A comparison of Chinese,Japanese, and Korean shipyard production technology

This paper compares Chinese, Korean, and Japanese shipyard production technology. Development in the world shipbuilding over recent years has influenced focus areas related to shipyard manufacturing technologies and product performance. Software systems, information technology, production technology, and local challenges of shipyards are compared with shipbuilding outputs among these three countries. Various technologies developments, shipyard production and the problems in Chinese, Japanese, and Korean shipyards are discussed respectively. Finally, future areas of research are pointed out.     

胶粘剂在客车制造中的应用

在客车装配中使用胶粘剂,具有很多优点,其特殊的功能与效果是焊接、铆接、螺栓连接等工艺方法所无法代替的。随着胶粘剂产品的丰富与完善,它在客车制造领域发挥着越来越重要的作用。     

浅谈一种低能见度下车辆雾灯自动开启的装置及方法

低能见度很大程度上影响着车辆行驶安全,本文主要阐述了一种低能见度下车辆雾灯自动开启的装置及方法,该研究的推广可以减少低能见度下公路交通安全事故发生的概率。