三峡临时船闸引航道外河段通航条件试验研究

对临时船闸引航道口门区及其以外河段按设计方案整治前后通航水流条件进行了对比试验研究，结果表明，采用炸礁、疏浚、建堤相结合的措施可以显著改善其通航条件，当长江流量为４５０００ｍ３／ｓ时，上游引航道口门区的最大横向流速与回流流速分别为０．３ｍ／ｓ和０．３８ｍ／ｓ，口门区以上河段航道中心线上的表面流只有２～３ｍ／ｓ；下游引航道口门区流速较小，口门区以下河段航道中心线上的表面流速大多在２ｍ／ｓ以内，经过整治后，水流条件满足通航要求     

水平圆管内油水两相分散混合液的流动特征

管道内油水两相分散流动中的压降受相含率、相分布和流速等参数的影响,研究表明同一混合液流速条件下,随体积含油率的增大,压降呈现为先增加后减小的趋势,在连续相的相转化点处压降达到峰值。该文结合均相流模型和非牛顿流体流动理论,对管道内油水两相流动的压降进行分析,结果显示已有混合液表观黏度预测模型计算得到的压降与实验值存在较大偏差。综合考虑管道流动中油水两相的相分布特征,优化得到了油水分散混合液表观黏度的预测模型,可应用于计算流动中的压降,且精度均在10%以内,为管道混输系统的设计,以及两相分散流动理论的发展提供可靠的理论依据。     

白云水电站高水头明流泄洪洞水力学问题的试验研究

白云水电站泄洪洞系“龙抬头”式明流隧洞。百年设计洪水位５４１．８０ｍ，对应的下泄量１１９７ｍ＾３／ｓ；二千年校核水位５４６．３０ｍ，对应的下泄量１４７３ｍ＾３／ｓ。泄洪洞布置在大坝左岸，断面为城门洞型，洞轴线与河床中心线交角约４５度。洞进出口水位差１００余米，洞内最大流速４３ｍ／ｓ，高速水流问题十分突出。通过１：４０的水工模型试验，对泄洪洞体型、掺气减蚀设备、挑流消能工进行了多种方案的优化，较好地     

钉螺起动流速试验研究

 阐述了钉螺起动流速试验研究成果。由于钉螺对河床具有吸附作用，因而钉螺起动可概括为三种不同起动状态：第一种为定床有吸附力起动，起动流速在１．０ｍ／ｓ以上；第二种为动床有吸附力起动，起动流速约在０．３～０．４ｍ／ｓ之间；第三种为无吸附力起动，起动流速在０．１４～０．１９ｍ／ｓ之间。钉螺无吸附力起动可利用钉螺起动流速公式计算。     

三峡工程溢流坝掺气减蚀研究

三峡工程最大水头１１３ｍ，溢流坝最高流速达３５ｍ／ｓ，对泄流面平整度要求很高，施工很难作到。为方便施工和溢流面不发生空蚀，研究采用掺气槽。结合国内外已建工程，尤其是乌江渡工程的经验，三峡工程表孔选用组合式掺气槽，其面积取６．８ｍ＾２，槽深１．２ｍ，挑坎高０．８ｍ，通气孔直径１．３ｍ，槽内负压值６６７ｍｍ水柱，通气孔布置在两侧闸墩上。深孔掺气槽参考龙羊峡水电站的突跌形式，弧门下游跌差２．０ｍ，通气孔     

钢筋混凝土井管的成井工艺

钢筋混凝土管造价为钢管的１／３，孔隙率达１７％，接近铸铁井管，而大于素混凝土井管。成井工艺：１、加大开孔尺寸，并采用两次钻孔新工艺，即先用５００ｍｍ钻头开孔，再用７００ｍｍ钻头扩孔。２、推行无棕过滤成井工艺，通过设计使滤水流速小于砂粒起动流速，并加厚滤料层至１２～１５ｃｍ。３、采用托盘下管技术。４、采用预埋钢圈与螺干，施工时周围焊接，使井管整体性、密封性能增强。５、增设集水槽，降低进水阴力及水跃值，扩大进水面积。采取上述工艺效益显著。钢筋混凝土井管每眼井费用仅及铸铁管的１／２，而涌水量是后者的２倍。水位降深，在相同流量时，前者小于后者。（唐茂元）     

水平井筒变质量分散泡状流压降的理论与实验研究

由于水平井筒和常规水平管道中气液两相流动的相似和差别，可以预知常规水平管流的压降计算方法对于井筒流动来说就需要进行修正或扩展。本文对气、液两相分别应用质量守恒方程和动量守恒方程，考虑管壁存在人流或出流对于分层流流型压降的影响，得到水平井筒气液两相变质量流动分散泡状流流型的压降计算方法。同时，设计并建立了水平井筒流体流动模拟实验装置，在轴向为气液两相流动的前提下分别进行了上管壁单孔眼注入和下管壁单孔眼注入的压降实验研究，获得了大量的实验数据。实验数据和理论计算结果吻合很好，这表明该计算方法具有实际应用价值。     

水平井筒油水变质量分散流动压降研究

针对水平井筒中油水两相变质量流动,从理论和室内实验两个方面对分散流型下压降进行了研究,着重考虑壁面流体的流入对壁面摩阻系数的影响与不同流型间的转换。根据质量守恒、动量守恒方程,建立了水平井油水两相分散流型下压降预测模型。采用水、白油为实验介质,测量了水平管不同注入比、不同含水率下油水两相流压降值。实验结果分析表明,当含水率为40%时,油水发生反相,管道中流动压降最大,这和Brinkman/Roscoe混合黏度公式计算出的反相点一致。同时,压降模型预测结果与实验结果相比较平均相对误差为13.6%。     

大口径混凝土压力管道工程设计与施工中应注意的问题

近年来，由于水资源形势的日趋紧张以及人们对农业节水观念的逐渐加强，在我国北方于旱地区，采用大口径混凝土压力管道输水进行农业灌溉的工程也呈增长趋势。笔者有幸参加了山西省内的几处灌溉管道工程的施工，并对已竣工工程进行过专门检查，总结出在大口径混凝土压力管道工程设计与施工中普遍容易出现的一些问题，现略述之，希望能够引起有关水利同仁关注，从而保证工程从技术、经济上更加合理。 一、设计上的问题 １．管径的确定 对管道系统工程，管道部分投资往往占整个工程的７０％以上，而管道直径的确定不仅对管网的造价产生影响，而且影响着管道系统的水力条件。当前，管径的确定，最常用的是“经济流速法”，即按下式计算： Ｄ＝＊－ｘｉ 式中：ｏ：管段通过的流量，ｍ’／ｓ， 卜：管内经济流速，ｍ／ｓ。 影响经济流速的因素很多（如管材价格，施工条件动力费用，投资偿还期等），主要归结为管网的造价和经营费用两项，我国各地区因上述因素的差异，其经济流速是不同的，设计实践中，在缺乏经济流速分析资料时，常采用平均经济流速来选择管径，具体数值如下： Ｄ二１００—４００ ｍｍ 采用 Ｖｅ二０．６－０．９ ｍ八 Ｄ＞４００ ｍｍ 采用 Ｖｅ＝０．９—１．４ ｍ／ｓ ...     

粘弹可瘪管的位移振荡研究

本文建立了研究粘弹性可瘪管脉动流位移振荡的实验和理论模型，归结出了管壁位移振荡的控制方程，并应用摄动方法求出问题的摄动解。文章最后还给出了粘弹可瘪管位移振荡发生的判别准则和三种不同流动状态区域，并讨论了来流速度和管壁粘性等参数对这些区域的影响情况。     

虹吸管道水气两相流动过流能力的试验分析

通过对虹吸式输水管道输水能力的试验研究,观测到不同安装高度下的气液两相流现象。量测了不同安装高度相应水位差下的流量的大小,并分析了流量变化规律。研究发现,随着安装高度的增大,虹吸管内气液两相流流型由气泡流转化为气团流。分析原因发现在安装高度h_s=2 m时,流量减小率与面积减小率相等,表明气液两相流时过流面积小于液相满流时过流面积是流量的减小的主要原因;当安装高度h_s2 m时,流量减小率与面积减小率相差较大,表明流量的减小不仅与面积变化有关,还应与沿程阻力系数有关。掺气浓度的增大使管内压降增大,压降的增大导致了管内阻力增大,从而使沿程阻力系数增大,而导致流量减小。     

Experimental and Numerical Investigations on Horizontal Oil-Gas Flow

Experiments were carried out to investigate the characteristics of oil-gas flow in a horizontal pipe on a large scale (with the inner diameter D = 125 mm). With the experimental data, the flow patterns were presented. Through the analyses for the flow regime transition, it was found that there was a critical superficial velocity of liquid phase for the flow regime transiting from stratified flow to slug flow. The slug flow could not occur until the superficial velocity of liquid phase was higher than the critical velocity. For the flow pattern transiting from stratified to slug flow, the transmitting velocity of gas phase decreases with the augmentation of superficial velocity of liquid phase. On the basis of the experiments, numerical simulations of different flow patterns and their transitions were performed with the use of the Volume Of Fluid (VOF) technique. The results of the computations are shown to match well with the measured data in the experiments.     

LIQUID-GAS TWO PHASE FLOW RATES METERING BY DUAL PRESSURE DIFFERENTIAL MEASUREMENTS

The measurement of the overall mass flow rates in a two phase, gas/liquid pipeline is considered on the basis of dual pressure differential measurements for a combined contraction/frictional pipe type of flow meter and a numerical model to predict overall mass flow rates from pressure differentials measured from this type of flow meter is presented. The experiments generally conform with the predictions of the flow rates prediction model. Whilst the practicability of such metering of two phase flows is clearly demonstrated, application of the method would require careful calibration to allow for the influence of nozzle coefficients, pipe Reynolds number and void fraction upon the one dimensional compressible flow equations through wall friction factor and interphase slip effects.     

CHARACTERISTICS OF PRESSURE DROP AND CORRELATION OF FRICTION FACTORS FOR SINGLE-PHASE FLOW IN ROLLING HORIZONTAL PIPE

Gas-liquid two-phase flow occurs increasingly in some dynamic devices operating in the oceanic condition. The relative data are limited with respect to flow characteristics, so the present study is to investigate systematically single-phase pressure drop, and to develop the theory for frictional factor under the rolling condition. Using deionized water as the test fluid, a series of experiments of single–phase flow were conducted in pipe with the inner diameter of 34.5 mm. The test section was horizontally settled on the rolling apparatus, and its regularity was similar to simple harmonic motion. It is found that the pressure drop during rolling motion fluctuate with the change of the rolling period and rolling angle, which is significantly different from fluid motion in a steady state. By the contrast between experiment results and stable-state theory values, existing correlations can not predict present frictional factor very well. Therefore, in the present article, the single-phase frictional factor is correlated with the Reynolds number for rolling motion, and its computated results agree well with experimental data.     

INFLUENCE OF SURFACTANT ON TWO-PHASE FLOW REGIME AND PRESSURE DROP IN UPWARD INCLINED PIPES

The influence of a surfactant on the two-phase flow regime and the pressure drop in upward inclined pipes is investigated for various gas/liquid flow rates.The air/water and air/100 ppm sodium dodecyl sulphate aqueous solution are used as the working fluids.The influence of the surfactant on the two-phase flow regime in upward inclined pipes is investigated using the electrical tomographic technique.For 0o,2.5o and 5o pipe inclinations,the surfactant has obvious effect on the transition from the stratified wavy flow to the annular flow,and the range of the stratified smooth flow regime is also extended to higher gas velocities.For 10o pipe inclination,no stratified flow regime is observed in the air/water flow.In the air/surfactant solution system,however,the stratified flow regime can be found in the range of and.For all inclination angles,the changes of the pressure gradient characteristics are accompanied with the flow pattern transitions.Adding surfactant in a two-phase flow would reduce the pressure gradient significantly in the slug flow and annular flow regimes.In the annular flow regime,the pressure gradient gradually becomes free of the influence of the upward inclined angle,and is only dependent on the property of the two-phase flow.     

虹吸管内气团流流型时过流能力计算

该文针对非驼峰式正虹吸管道进行了系列试验,量测了不同安装高度、不同水头差时管内呈现气团流流型时的过流能力和截面含气率。试验结果表明,气团流流型下虹吸管道过流能力随虹吸管安装高度的增大而减小,不能采用常规有压管流公式计算气团流流型时虹吸管过流能力。基于试验结果分析了影响气团流过流能力的因素,结果表明气体存在对流动沿程阻力系数影响不可忽略,过流能力计算时不能直接采用单一液相流动沿程阻力系数。不同安装高度时虹吸管内过流面积减小不是导致输水流量减小的唯一因素,除了考虑过流面积减小对过流量的影响外,还应考虑含气率大小引起的μ_0或λ变化对流量的影响。结合试验结果和数值分析,推导出适用于气团流流型下伪空化现象明显、安装高度不大于8 m的水平管段较长考虑含气率大小的虹吸管流量系数计算公式,修正和完善了有压管流过流能力计算公式,经检验公式计算误差小于±7%。     

FLOW PATTERN AND PRESSURE LOSS OF OIL-WATER TWO-PHASE FLOW IN HORIZONTAL STEEL PIPE

Experimental Study on oil-water two-phase flow patterns and pressure loss was conducted on a horizontal steel pipe loop with 26. 1mm inner diameter and 30m total length. The working fluids are white oil, diesel oil and tap water. Several instruments, including a new type of liquidprobe are successfully integrated to identify 7 different flow patterns. The characteristics of the flow patterns and the transition process were observed and depicted in this paper.Investigation revealed that the pressure loss was mainly depended on the flow paiterns.     

Single-phase and two-phase flows through helical rectangular channels in single screw expander prototype简

The CFD simulations are carried out for the flows in a horizontally oriented helical pipe with various inlet sectional liquid holdups and coil pitches （ H ） . The development of the pressure fields for the single phase air flow and the air-water two-phase flow through the helical rectangular channels is studied. The points with a higher pressure often become the position of expansion leakage. The liquid phase distribution at these points can prevent the leakage of air. It is shown that the increase of the inlet sectional liquid holdup may increase the local liquid holdup at the outmost side of the helical channel. Based on the published pressure drop correla-tion, a new modified relation for predicting the pressure drop in the helical rectangle channel is proposed.