典型流型探针信号的PSD特征

通过对自制电导探针采集的液位信号进行统计分析，得到分层流、间歇流、环状流3种流型下流动的功率谱密度PSD特征，并与相同工况下的压力信号PSD特征作了比较，发现利用探针信号的PSD特征可以容易地区分3种不同流型，为流型的识别提供了新的方法。     

多相流相分率测量技术研究进展

综述了近年来国内外多相流相分率测量技术的研究进展，重点总结了电学法、射线吸收法、射线散乘风破浪地和光学法等测量方法的基本原理和发展概况；简单总结了热学法、核磁共振法、微波法、脉冲中子法和模糊评判法等测量方法的基本原理。并且介绍了环状探针、线平行探针、双探针、电容探针、光纤探针等测量装置的原理、应用特点和Schlumberger剑桥研究所研制的高频电阻探针的安装实例。还简单介绍了有关的实验结论和相分率计算公式，并分析了各种测量技术存在的问题。     

两相管流工艺计算软件的研制

利用流体力学理论，结合目前国内外最新的两相流理论和实验研究成果，在描述气液两相管流水力计算、热力计算和流型判断的数学物理模型的基础上，研制出适用于海洋、沙漠、丘陵地区，原油与伴生气、凝析天然气与凝液混合输送工艺的一套新的计算模拟软件TFTCS．对TFTCS的结构、功能、适用范围作了介绍，用该软件对某湿天然气管线进行了模拟计算，同管线生产数据进行了对比，并与国外同类软件PIPEPHASE进行了对比验算。实际应用表明，该软件功能完善、操作方便、计算结果可靠，能满足油气混输管线的设计计算和生产管理的需要。     

一组油气两相管流水力学模型的评估与优选

现有的两相流水力计算模型大多数是在特定的试验条件下，得到的经验或半经验公式，应用于油气田两相流生产管线，普遍适用性较差。对国外稳态两相流软件中常用的13种水力学组合模型，在持液率计算和流型判断方面进行了改进和补充，并用JZ20—2凝析气管道的实际生产数据对这些水力模型进行评估，筛选出计算精度相对较高的EF、BBM、BBME等3种模型。统计误差分析和灰色关联法用于水力学模型评估的可靠性在实际应用中得到了证明，为工程设计者选择合理的水力计算模型提供了一种有效的方法。     

油田地面集输管道砂、油-水固液两相流流型的研究

随着我国东部油区进一步开发，井内出砂、出水问题日益加重。油田地面集输管道中砂、油－水固液两相流动管道破损起着至关重要的作用。本文通过对固液两相流流型的研究，得出了广泛意义上的流型判断计算公式。据此工控制流型的最佳参数，对实际生产具有一定的指导意义。     

椰子油对气液两相螺旋流流型和压降的影响研究

文中分析了添加表面活性剂的气液两相螺旋管流的特点及研究现状,用实验的方法研究了可降解型天然椰子油体系下的气液两相流螺旋流流型及压降,对螺旋流流型进行了划分,并与不含表面活性剂体系下的气液两相流螺旋流流型进行了对比,建立了以叶轮起旋的表面活性剂体系下的气液两相螺旋流压降模型。研究表明:添加表面活性剂可以降低表面张力,使流型发生转变;流速、含气率及活性剂浓度均会对管道内的气液两相螺旋流流动压降产生影响。     

水平管段塞流液塞持液率试验研究与预测模型对比

在内径50 mm、长27.3 m的水平管上利用空气-水作试验介质对段塞流的压力和液塞持液率进行了试验研究。采用压力传感器测量压力变化,采用平行电导探针测量液塞持液率变化。通过试验发现：液塞通过测量点时持液率的变化比压力变化迅速,持液率能更真实地反映段塞流动特性,可以用持液率的波动情况来确定液塞频率。将液塞持液率模型预测值与试验值进行了比较,结果表明,水平管大多数试验工况下的Zhang H Q模型预测值与试验值吻合最好。     

管道固-液两相流研究的意义、内容和方法

固体物料的管道水力输送技术广泛应用于国民经济众多领域，针对固体物料的多样性，复杂性以及管道固液两相流动的特点，阐述了固液两相流动与单相流动的主要差异，研究内容，研究方法和实验手段，简要介绍了江河湖库疏浚工程中管道固液两相流动的研究。     

质量流量计传感器理论分析

从理论上分析了一种全新思维的质量流量计传感器，其形状为－Ｕ型管，当流体经过时，检测到的质量不受温度，压力，密度，粘度和电导的影响，其测量精度可达０．１％，可广泛用于产品质量控制，工厂内部计量和国际贸易等。     

数值方法计算热油管道参数的数学模型及程序系统（一）

通过深入分析存在牛顿和假塑性流体流型热输原油管的流动特征，本文给出管道中可能出现的４３种流型流态组合图，并在此基础上建立了用数值方法计算工艺参数的数学模型。     

管道内污水两相流的阻力计算

目前的污水管道设计是将污水在管道内的流动视为单相均匀流,主要用谢才(Chezy)公式进行水力计算。由于存在管线长、流量大以及区域地形变化幅度较大等因素,建设区域排水系统需要采用新的方法,以便较准确的计算水头损失。文中将污水视为液-固两相流体。对于沿程阻力的计算,将流体分为均质流与非均质流,分别给出沿程阻力系数的计算公式;对于局部阻力,则借用气-固两相流动的局部阻力系数计算公式。最后得出了两相流情况下与单相流情况下的阻力系数区别。结论是沿程阻力系数的区别可不计,局部阻力系数差别较大,在进行设计时必须考虑。     

燃气调压器声发射信号特征与流量关系分析

文中提取燃气调压器声发射信号的标准差、峭度这两个时域特征及重心频率、均方根频率这两个频域特征,分析特征与流量的对应关系,使用相关系数进行评价。基于北京某调压站采集的声发射信号及流量数据,实验结果表明,流量与标准差、峭度、重心频率、均方根频率的相关系数分别为0.8192、0.2889、0.7745、0.641。可见标准差、重心频率及均方根频率与流量相关性较强,峭度与流量相关性较弱。     

复杂地表气液混输管路持液率影响分析

为促进生产工况参数调整,缓解气液混输管路积液问题,对比研究了考虑高程变化的起伏管路以及不考虑高程变化的水平管路在气液比、管径、输送压力工况参数变化下对管路持液率的影响规律,以及地形变化对持液量的影响情况。通过实际工程案例验证了研究成果对促进管路积液主控因素判断和工况参数调整具有较好的实用性和可靠性。     

A phase-based smoothing method for accurate traffic speed estimation with floating car data

In this paper, a novel freeway traffic speed estimation method based on probe data is presented. In contrast to other traffic speed estimators, it only requires velocity data from probes and does not depend on any additional data inputs such as density or flow information. In the first step the method determines the three traffic phases free flow, synchronized flow, and Wide Moving Jam (WMJ) described by Kerner et al. in space and time. Subsequently, reported data is processed with respect to the prevailing traffic phase in order to estimate traffic velocities. This two-step approach allows incorporating empirical features of phase fronts into the estimation procedure. For instance, downstream fronts of WMJs always propagate upstream with approximately constant velocity, and downstream fronts of synchronized flow phases usually stick to bottlenecks. The second step assures the validity of measured velocities is limited to the extent of its assigned phase. Effectively, velocity information in space-time can be estimated more distinctively and the result is therefore more accurate even if the input data density is low.The accuracy of the proposed Phase-Based Smoothing Method (PSM) is evaluated using real floating car data collected during two traffic congestions on the German freeway A99 and compared to the performance of the Generalized Adaptive Smoothing Method (GASM) as well as a naive algorithm. The quantitative and qualitative results show that the PSM reconstructs the congestion pattern more accurately than the other two. A subsequent analysis of the computational efficiency and sensitivity demonstrates its practical suitability.     

油田管线液固两相流动磨蚀实验研究

胜利油田孤东区块出砂严重 ,污水矿化度高 ,溶解氧、二氧化碳、硫化氢等对混输管线的腐蚀及损坏特别严重。通过室内磨蚀实验就液固两相流动对混输管线损坏的进行研究 ,以期改变孤东油田目前由于腐蚀严重、管线频繁穿孔给原油生产带来的被动局面。     

基于CFD洗扫车料箱气固两相流模拟

随着中国城市化进程的加快,专业并且符合中国国情的扫路车需求日益增加,研究洗扫车的气力输送系统对相应结构进行优化就显得尤为重要。本文对典型的环卫洗扫车料箱部件内的流动情况进行两相流仿真分析,直观的表达料箱内部的速度、密度、压力值,结果对料箱结构的设计具有建设意义。     

Understanding the structure of hyper-congested traffic from empirical and experimental evidences

We study in this paper the structure of traffic under hypercongestion, which is a controversial issue between traditional two-phase traffic theory and Kerner’s three-phase theory. By analyzing video traffic data from a section of the Nanjing Airport Highway, it is found that traffic states inside hypercongestion are not homogeneous, which contradicts the existence of a “Homogeneous Congested Traffic” state claimed in two-phase traffic theory. Analysis of vehicle trajectories and velocities obtained from an experimental car-following study with a platoon of 25 vehicles also confirms the above findings. Furthermore, it is also found from the video traffic data that the structure of hypercongested traffic varies only slightly with location, which might be due to small jams inside hypercongested traffic merging into larger ones slowly and/or larger jams sometimes breaking into small ones. Finally, the implications of our observations on traffic modeling have been discussed.     

Characteristics of speed dispersion and its relationship to fundamental traffic flow parameters

Speed dispersion is essential for transportation research but inaccessible to certain sensors that simply record density, mean speed, and/or flow. An alternative is to relate speed dispersion with these available parameters. This paper is compiled from nearly a quarter million observations on an urban freeway and a resulting data-set with two speed dispersion measures and the three fundamental parameters. Data are examined individually by lane and aggregately by direction. The first dispersion measure, coefficient of variation of speed, is found to be exponential with density, negative exponential with mean speed, and two-phase linear to flow. These empirical relationships are proven to be general for a variety of coefficient ranges under the above function forms. The second measure, standard deviation of speed, does not present any simple relationships to the fundamental parameters, and its maximum occurs at around a half to two-thirds of the free flow speed. Speed dispersion may be significantly different by lane.     

Existence of urban-scale macroscopic fundamental diagrams: Some experimental findings

A field experiment in Yokohama (Japan) reveals that a macroscopic fundamental diagram (MFD) linking space-mean flow, density and speed exists on a large urban area. The experiment used a combination of fixed detectors and floating vehicle probes as sensors. It was observed that when the somewhat chaotic scatter-plots of speed vs. density from individual fixed detectors were aggregated the scatter nearly disappeared and points grouped neatly along a smoothly declining curve. This evidence suggests, but does not prove, that an MFD exists for the complete network because the fixed detectors only measure conditions in their proximity, which may not represent the whole network. Therefore, the analysis was enriched with data from GPS-equipped taxis, which covered the entire network. The new data were filtered to ensure that only full-taxi trips (i.e., representative of automobile trips) were retained in the sample. The space-mean speeds and densities at different times-of-day were then estimated for the whole study area using relevant parts of the detector and taxi data sets. These estimates were still found to lie close to a smoothly declining curve with deviations smaller than those of individual links – and entirely explained by experimental error. The analysis also revealed a fixed relation between the space-mean flows on the whole network, which are easy to estimate given the existence of an MFD, and the trip completion rates, which dynamically measure accessibility.