垂直上升管中油水两相流流型表征

在含水率 5 1%～ 91%、油水两相流总流量 10～ 6 0m³·d^-1范围内 ,对垂直上升油水两相流流动工况的电导波动信号进行了分形及混沌时间序列分析 .当含水率为 6 0 .5 %～ 91%时 ,所提取的分形维数及吸引子相关维分别在 1.0 0 6～ 1.6 31及 4.30～ 6 .77之间 ;当含水率为 5 1%或 5 1.5 %时 ,所提取的分形维数及吸引子相关维分别在 1.17～ 1.75 8及 5 .46～ 7.0 5之间 ,且分形维数及混沌吸引子相关维数随总流量呈不规则突变 ,并与复杂功率谱特征及流型图上的过渡流型相对应 ,表明了分形维数及混沌吸引子相关维数对油水两相流流型变化具有敏感的“指示器”特性     

气液两相流流量变化瞬态特性

在气液混输管线中常发生流量变化引发的瞬态过程,在大型多相流实验环道上进行了流量变化的瞬态实验.气量突增产生压力过增量,它的产生与流型有关：分层流的过增量是由于气体的惯性;在气团流和段塞流下则是由于气体压缩性和液体惯性的联合作用.气量突降时,膨胀波沿程传播.气量变化的瞬态过程可能出现对应准稳态变化没有出现的流型.与气量突变相比,液量突变引起的压力和流型变化较平缓,瞬态效应小.流量变化后产生沿线传播的压力波和空隙波,二者与流型相关,决定瞬态过程的发展.压力变化的传播速度在气量变化时等于声速,在液量变化时等于空隙波波速.     

MODELING OF CONCENTRATED LIQUID-SOLIDS FLOW IN PIPES DISPLAYING SHEAR-THINNING PHENOMENA

This paper describes our work in modeling concentrated liquid-solids flows in pipes. Based on our previous analyses, some concentrated liquid-solids suspension flows display shear-thinning rather than Newtonian phenomena. Therefore, we developed a new two-phase non-Newtonian power-law model that includes the effect of solids concentration on solids viscosity. With this new two-phase power-law solids-viscosity model, and with constitutive relationships for interfacial drag, virtual mass and shear lift forces, and solids partial-slip boundary conditions at the pipe walls, COMMIX-M is capable of analyzing concentrated three-dimensional liquid-solids flows.     

TRANSITION TO SLUG FLOW IN HORIZONTAL PIPES

The transition to slug flow in horizontal pipelines is reviewed. Experimental observations of the interface prior to slugging and of the effect of physical properties and pipe diameter on the transition are described. Theoretical progress in understanding the initiation of slugging through a stability analysis is summarized. Theories are classified by whether they invoke a long-wave assumption and whether they include viscous and nonlinear effects. Despite considerable progress, a general theory for predicting the initiation of slugging for arbitrary fluids in pipelines of varying size and pressure is far from being realized.     

TRANSITION TO SLUG FLOW IN HORIZONTAL PIPES

The transition to slug flow in horizontal pipelines is reviewed. Experimental observations of the interface prior to slugging and of the effect of physical properties and pipe diameter on the transition are described. Theoretical progress in understanding the initiation of slugging through a stability analysis is summarized. Theories are classified by whether they invoke a long-wave assumption and whether they include viscous and nonlinear effects. Despite considerable progress, a general theory for predicting the initiation of slugging for arbitrary fluids in pipelines of varying size and pressure is far from being realized.     

GENERALIZED EQUATION OF PRESSURE LOSSES IN DISPERSED POWDER FLOW THROUGH VERTICAL PIPES

The results of the experimental investigation of pressure losses in a vertical co-current flow of a two phase solid particles-air system are given for the transient character of flow of the continuous phase. The dispersed phase was formed by 6 fractions of polypropylene particles and 5 fractions of glass ballotini of 90 · 10^-6-370 · 10^-6 m and 60 · 10^-6-200 · 10^-6 m equivalent diameter, respectively. The relative mass fraction of solid particles varied over the interval 0-1 dilute. On the basis of experimental data the generalized equation for the computation of pressure losses for the vertical transport was derived. The pressure losses calculated on the basis of this equation were compared with data published by 9 authors.     

FLOW OF SUPERSATURATED SOLUTIONS IN PIPES. MODELING BULK PRECIPITATION AND SCALE FORMATION

Pipe flow of supersaturated solutions of sparingly soluble salts is simulated in this work. Models from the literature are selected to represent individual processes, which may occur simultaneously, such as nucleation, particle growth, coagulation, and particulate and ionic deposition on the pipe wall. As regards formulation, a fairly comprehensive population balance equation is employed for the sol:d phase combined with mass balance for the ionic species. A sufficiently accurate, yet computationally convenient, discretization scheme is used in the simulation algorithm. Arbitrary parameters are avoided with the exception of surface reaction parameters which are determined from experimental data since no theoretical values are available. The PbS-water system (previously studied experimentally in this laboratory) serves as a test case. The PbS effective surface energy is estimated from experimental data. Predictions are quite encouraging, reproducing statisfactorily the measured “beH”-shaped deposition versus pH curves. The predicted particle size distributions and their evolution are physically realistic, qualitatively and quantitatively. Despite necessary future improvements, the proposed simulation algorithm is already considered a useful tool for scale up in industrial and other applications.     

滴流床反应器的脉冲特性

滴流床中气液流速较高时会产生脉冲流。脉冲特性可表示为：脉冲频率、脉冲速度、脉冲持液与脉冲间持液。这些参数可用气液流速、填料特性及气液物性来度量。在宏观物料衡算基础上推得脉冲速度的模型。脉冲持液就是反应器的动持液；脉冲持液与脉冲间持液之比近于1．5。发现脉冲频率完全受表观液速与临界液速的差值所控制。获得了三个关联式，涉及不同系统，也包含文献数据。     

低浓度悬浮液的动态过滤特性研究

文章以超细CaCO_3颗粒和水的悬浮物为对象,研究了旋叶式过滤机中低浓度悬浮液的浓度、旋叶转速、过滤压力对过滤速率、滤液澄清度的影响,结果表明在低浓度范围内的动态过滤具有过滤速率高、滤液澄清度高等优点,是一个很有应用价值的过滤方法。     

STRATIFIED THREE PHASE FLOW IN PIPES - STABILITY AND TRANSITION

The stability of stratified three phase flow (water-oil-gas) was analyzed using two approaches: A straight forward Kelvin-Helmholtz stability analysis on the two interfaces termed here the “exact” approach and a simplified approach. 1 n the “exact” approach the two interfaces (water-oil and oil-gas) are perturbed, while in the simplified approach the perturbed interface is only the upper oil-gas interface. Both approaches include the viscous Kelvin-Helmholtz analysis in which the shear stresses are laken into account and the inviscid K H analysis where the shear stresses are neglected.

Comparison with some experimental results suggests that the simplified method is a better predictor of the transition from stratified flow than the “exact” approach, suggesting, perhaps, that the stability analysis on the upper interface alone is preferred.     

膜超滤法处理合成胶乳废水

针对工业生产合成橡胶厂排放的含胶乳乳化液废水（又称白水）,建立了超滤膜处理实验装置。进行了膜组件和膜材料的选择;测试了错流速度、压力、温度和固含量对渗透通量的影响;对胶乳破乳现象作了初步的分析。     

CHARACTERISTICS OF TURBULENT TWO-PHASE FLOW

The characteristics of turbulent bubbly regime of gas and liquid flow in a horizontally oriented large pipeline have been presented. Various techniques such as hot film anemometer, Pitot tube, miniature pressure transducers and orifice meters were successfully employed to measure the two-phase flow parameters, void fraction, mixture velocity and wall pressure fluctuations.

Different semi-empirical correlations have been developed for predicting the turbulent characteristics in radial and axial directions in terms of the volumetric flow ratio. Spectral analysis was performed to study the turbulent flow fluctuations and their distributions over different wave numbers. Finally, the fully developed flow has been analytically and spectrally studied.     

弯管扭转切换区流场分析

当前对于单段弯管内部流场的演变与发展情况已有众多研究结果,可是对于多段弯管组合下的流动情况分析并不多,特别是对于多段不同弯曲半径的弯管组合,其管段间过渡区域的流动体现了不同Dean数流动的组合,对于Dean数占主导地位的二次流动而言该数的变动对整个流动都会产生较大的影响.本文使用数值计算的方法分析了弯管特殊组合形式下管段过渡区域的流场演变情况,并分析了不同边界条件下该区域流场变动对内部流体微团运动可能产生的影响.结果显示,使用不同曲率的弯管进行组合,产生的流场对截面上的物质运动促进作用最明显.     

STEADY LAMINAR FLOW THROUGH TWISTED PIPES: FLUID FLOW AND HEAT TRANSFER IN RECTANGULAR TUBES

Fluid flow and heat transfer characteristics in a twisted rectangular tube having an aspect ratio of two were studied using a numerical solution to the momentum and energy equations. Fluid flow solutions are presented for a fully developed laminar flow of a Newtonian fluid. Heat transfer results are presented for the case of axially uniform wall temperature. For the case of peripherally uniform wall temperature, the overall Nusselt number in a twisted rectangular tube was found to be higher than a straight tube by up to 30 percent over certain ranges of twist lengths. However, for the case of non-uniform wall temperature, the overall absolute Nusselt number increased very rapidly with decrease in the twist length     

PERFORMANCE CHARACTERISTICS OF RING PROMOTER IN HOMOGENEOUS FLOW OF THE ELECTROLYTE AND IN FLUIDIZED BEDS

Performance ratios and pumping power ratios are evaluated in a circular conduit in the presence of a ring promoter in the absence and the presence of fluidizing solids. Qualitative effects of cross-sectional diameter of the ring, spacing between the rings, and diameter of the particle on performance ratio, pumping power ratio, and efficiency index are reported.     

PERFORMANCE CHARACTERISTICS OF RING PROMOTER IN HOMOGENEOUS FLOW OF THE ELECTROLYTE AND IN FLUIDIZED BEDS

Performance ratios and pumping power ratios are evaluated in a circular conduit in the presence of a ring promoter in the absence and the presence of fluidizing solids. Qualitative effects of cross-sectional diameter of the ring, spacing between the rings, and diameter of the particle on performance ratio, pumping power ratio, and efficiency index are reported.     

水分散性聚氨酯中丙烯酸甲酯乳液聚合的研究

研究了在阴离子水分散性聚氨酯中丙烯酸甲酯乳液聚合的行为。讨论了聚氨酯用量对丙烯酸甲酯乳液聚合及其膜性能的影响。比较了聚氨酯乳液与丙烯酸甲酯乳液机械共混和共聚的膜性能的差别。     

多级闪发式海水淡化装置水流特性数值模拟

引　言目前国内外在陆上采用的海水淡化技术主要有蒸馏法和反渗透法两种 .蒸馏法的优点是装置费用随产量增加而明显减少 ,具有规模效应 ,且维护费用较少 ,产水水质很高 .在陆上使用的蒸馏法海水淡化设备一般为大型多级卧式闪发蒸馏装置 ,它由一系列逐级降压的闪发室串联而成 ,过热水在水位差作用下向下一级流动 ,靠逐级降压而保持的过热度使海水不断蒸发 ,产生水蒸气后冷凝成淡水 (图1) [1] .闪发室的结构形状并不复杂 ,但闪蒸过程涉及汽、液两相的流动、相变、热交换过程以及两Fig 1　SketchofMSFdesalinationdevice[1]相之间自由界面的…     

CHARACTERISTICS OF PULSING FLOW IN TRICKLE BEDS. IMPROVEMENTS OF A MACROSCOPIC MODEL

A rather simple macroscopic model, originally proposed by Dimenstein and Ng (1986), is examined by comparison with results of experimental work carried out in this laboratory recently. Several improvements are proposed relying either on new correlations or in better physical understanding obtained from the recent experiments. The model, despite its simplicity, is considered quite comprehensive and reliable (for the range of physical properties examined) providing good estimates of essentially all the significant time averaged characteristics of pulsing flow.     

非牛顿流体在气升式反应器中的流动特性

以非牛顿型流体在气升式内环流反应器中流动特性为研究对象，考察了在气－液－固三相体系中气含率和液体循环速度随不同的表观气速、固体颗粒粒径和浓度、设备结构尺寸的变化规律。对实验数据进行了回归处理得到气含率和循环速度的经验关联式，并对非牛顿型流体和牛顿型流体在同一反应器中的流动特性作了比较