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基于MODFLOW的岩溶管道水流模拟方法探讨与应用 被引量:19
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作者 赵良杰 夏日元 +3 位作者 杨杨 邵景力 易连兴 王喆 《中国岩溶》 CAS CSCD 北大核心 2017年第3期346-351,共6页
针对岩溶管道水流特征,选取广西寨底岩溶流域为研究对象,分别采用三维有限差分地下水流动模型(MODFLOW)中的Drain和River模块概化模拟岩溶管道特征,结合管道内上游、中游及下游三个观测孔对比分析两种方法的适用性,结果表明:末期等水位... 针对岩溶管道水流特征,选取广西寨底岩溶流域为研究对象,分别采用三维有限差分地下水流动模型(MODFLOW)中的Drain和River模块概化模拟岩溶管道特征,结合管道内上游、中游及下游三个观测孔对比分析两种方法的适用性,结果表明:末期等水位线图中位于管道两侧处流线均有形状突变,符合实际管道水流动态特征,且能模拟出管道内水位变化趋势。最后分析两种方法模拟管道水流的原理,Drain模块中岩溶管道仅起排水作用,不允许管道内水流流向周围含水层,而River模块允许岩溶管道水与周围含水层水流交换,因而相对Drain模块而言,应用River模块概化模拟岩溶管道更加精确。 展开更多
关键词 管道水流 岩溶含水层 数值模拟 MODFLOW
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基于管道水流发电的农业物联网供电系统设计 被引量:2
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作者 常晓敏 魏科宇 +3 位作者 左广宇 刘大雷 刘文浩 刘琪 《中国农村水利水电》 北大核心 2021年第12期144-149,共6页
为解决野外环境下,农业物联网监测设备的供电问题,设计了一套基于管道水流发电的农业物联网供电系统。系统基于管道流速1.5 m/s,管内水压200 kPa的工况完成水轮机、发电机设计,在此基础上设计系统电路、I/O扩展模块和控制策略,实现对监... 为解决野外环境下,农业物联网监测设备的供电问题,设计了一套基于管道水流发电的农业物联网供电系统。系统基于管道流速1.5 m/s,管内水压200 kPa的工况完成水轮机、发电机设计,在此基础上设计系统电路、I/O扩展模块和控制策略,实现对监测设备的稳定供电。通过试验测量,系统在无充电状态下,24 h蓄电池耗电量为43%;每天灌溉8 h,24 h内电量最低为69%,电量最高为100%。该系统成本低,发电量符合预期,能持续稳定地为农业物联网设备供电。 展开更多
关键词 管道水流发电 供电系统 农业物联网 系统电路 MPPT
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管道水流的水头损失系数 被引量:1
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作者 FadiZ.Kamand 樊哲本 《江西水利科技》 1991年第4期358-365,共8页
管道的水头损失直接影响水管和水泵尺寸的确定,也就是管网的水力平衡。所有沿程水头损失计算公式,在估算水管内壁糙率时都有误差。对于一定材料一定管径和流量的管道的阻力系数,不同的方程式可以估算出不同的沿程水头损失。在复杂管道... 管道的水头损失直接影响水管和水泵尺寸的确定,也就是管网的水力平衡。所有沿程水头损失计算公式,在估算水管内壁糙率时都有误差。对于一定材料一定管径和流量的管道的阻力系数,不同的方程式可以估算出不同的沿程水头损失。在复杂管道网络系统中,方程式或系数的小误差的累积,使各个管子水头损失或流量的计算值产生较大的误差。本文提出了三个广泛应用于管道摩阻方程摩阻系数有关的解决水头损失计算误差的数学关系式和诺模图。对象聚氯乙烯和铸铁管道来说,用Hazen—Willians(H—W)和Manning(Mn)公式得的水头损失与Darcy—Weisbach(D—W)得的水头损失相同。还介绍了摩阻系数随直径和水流条件而变化的情况,并讨论了运用计算机计算变化的沿程损失系数问题。 展开更多
关键词 管道水流 水头损失系数 管网 水力平衡
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考虑压力管道水流惯性和调速器特性的调压室临界稳定断面研究 被引量:15
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作者 郭文成 杨建东 +1 位作者 陈一明 单新健 《水力发电学报》 EI CSCD 北大核心 2014年第3期171-178,共8页
针对现有的调压室临界稳定断面公式没有考虑压力管道水流惯性和调速器的影响,本文建立了考虑这两个因素的水力-调速系统数学模型,证明出临界稳定断面判据为描述调节系统的线性常系数齐次微分方程的一阶导数项系数大于零,并据此推导出包... 针对现有的调压室临界稳定断面公式没有考虑压力管道水流惯性和调速器的影响,本文建立了考虑这两个因素的水力-调速系统数学模型,证明出临界稳定断面判据为描述调节系统的线性常系数齐次微分方程的一阶导数项系数大于零,并据此推导出包含压力管道水流惯性时间常数和调速器参数的临界稳定断面解析公式,此公式由引水隧洞项、压力管道项、调速器项组成,其中引水隧洞项即为托马公式,压力管道项为正值,调速器项为负值;最后揭示了调速器参数对临界稳定断面影响的数学本质:bt、Td对临界稳定断面增减性的影响存在临界值,但此临界值只是数学意义上的存在,工程实际中不会出现,临界稳定断面是bt、Td的单调递减函数。 展开更多
关键词 水电站 调压室 临界稳定断面 托马公式 压力管道水流惯性 调速器特性
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基于FLUENT的农业灌溉管路微型水轮机发电效率的分析与研究
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作者 李杰 翁泽城 潘鹤立 《节水灌溉》 北大核心 2023年第8期129-135,142,共8页
为了实现管道中水能发电满足智能灌溉系统供电需求,需要提高超微型水轮机的发电量和发电效率。使用DesignModeler和Soildworks建立了三维结构模型,将水轮机转轮不同的叶片数量和叶片角度分组并导入流体力学仿真软件Fluent中分析。根据... 为了实现管道中水能发电满足智能灌溉系统供电需求,需要提高超微型水轮机的发电量和发电效率。使用DesignModeler和Soildworks建立了三维结构模型,将水轮机转轮不同的叶片数量和叶片角度分组并导入流体力学仿真软件Fluent中分析。根据灌溉用水特点,设置在水压150kPa,水流速度1.33m/s的条件下进行仿真实验。在稳定旋转的条件下,分别对6、10、20、25、30叶片数和夹角60°、70°、75°、80°、90°的叶轮模型稳定后的转速进行仿真试验,发现在叶片夹角75°下,20和25片叶片时水轮机转速较快,分别为1185 r/min和1148 r/min。经过仿真试验,发现叶轮转速与其叶片长度的关系不明显。对有效输出功率和流场进行分析,发现当水轮机叶片为25片,夹角为75°时,为仿真实验中的最优组合。叶片数在6~20片时转速随着叶片数量增加而增加,20~30片则会骤降,叶片的角度在75°时转速最高,叶片长度对转速影响不大。研究结果表明通过调整其转轮数量和叶片角度对叶轮转速有明显提升,能有效提高输出功率,提高发电效率。 展开更多
关键词 FLUENT 超微型水轮机 智能灌溉 管道水流发电 叶片数量 叶片角度 发电效率
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蛇形冷却水管水温变化对水管冷却效果的影响 被引量:3
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作者 解宏伟 陈尧隆 《青海大学学报(自然科学版)》 2008年第1期1-5,共5页
根据管道中恒定平行层流的泊松方程和热传导理论,采用三维有限元仿真方法,对含有冷却水管的混凝土坝的冷却水管中水温的变化规律进行了研究,分析及算例结果表明:水管中径向和轴向均有变化,但其变化值不大,对水管冷却的整体效果影响很小。
关键词 大体积混凝土 温度场 冷却水管 管道水流
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基于雷诺数和直径比两个因素的同心环状缝隙流轴向速度试验研究 被引量:1
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作者 孙蕾 《中国农村水利水电》 北大核心 2018年第11期175-178,共4页
为了进一步研究同心环状缝隙水流特性,通过理论分析推导出环状缝隙流轴向速度的计算公式,得出雷诺数和直径比是影响其大小的主要因素,并结合模型试验研究如何影响,以及其与管道水流速度和圆柱体速度三者之间的关系。结果表明:环状缝隙... 为了进一步研究同心环状缝隙水流特性,通过理论分析推导出环状缝隙流轴向速度的计算公式,得出雷诺数和直径比是影响其大小的主要因素,并结合模型试验研究如何影响,以及其与管道水流速度和圆柱体速度三者之间的关系。结果表明:环状缝隙流轴向速度与雷诺数基本成正比的线性关系,同一直径比时,雷诺数越大,圆柱体速度增大最快,管道水流速度次之,环状缝隙流速增大最慢;直径比在0.5~0.7范围时,缝隙流速最大;雷诺数越大,达到稳定运动状态的直径比越小;直径比越大,达到稳定运动状态的雷诺数越小。因此从缝隙流量和系统稳定运行两个角度综合考虑时,建议选择雷诺数的范围为210 700~245 817,直径比为0.7。 展开更多
关键词 环状缝隙流 管道水流 轴向速度 雷诺数 直径比
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基于拟合方程的水表误差曲线校准方法 被引量:4
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作者 姚灵 《上海计量测试》 2013年第3期2-4,共3页
在传统机械水表上设置嵌入式计算机系统及特性校准算法和数据处理等软件,可将机械水表改造成宽量程高准确度的新型电子水表。水表特性的计算机校准过去大都采用查表法,致使校准工作量过大,校准效率低下。该文采用基于拟合直线方程的校... 在传统机械水表上设置嵌入式计算机系统及特性校准算法和数据处理等软件,可将机械水表改造成宽量程高准确度的新型电子水表。水表特性的计算机校准过去大都采用查表法,致使校准工作量过大,校准效率低下。该文采用基于拟合直线方程的校准方法,根据水表误差曲线的变化趋势,将曲线平坦部分划分成若干校准段,并用相应的直线方程予以拟合,使水表误差曲线控制在较小的误差范围内,也使校准效率得以明显提高。 展开更多
关键词 流量测量特性 仪表系数 特性校准技术 拟合直线方程 管道水流量测量
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基于特性校正技术的宽量程垂直螺翼式水表的研制 被引量:1
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作者 姚灵 陈良勇 +1 位作者 任江 左富强 《仪表技术》 2012年第11期5-8,共4页
在传统机械水表基础上,增加旋转量机电转换装置、嵌入式计算机系统、特性校正算法和数据处理软件等,可以使机械水表改造成极宽量程的新型水表。它的流量测量范围Q3/Q1在满足测量准确度条件下可扩至R=1000以上,但前提是机械水表要有良好... 在传统机械水表基础上,增加旋转量机电转换装置、嵌入式计算机系统、特性校正算法和数据处理软件等,可以使机械水表改造成极宽量程的新型水表。它的流量测量范围Q3/Q1在满足测量准确度条件下可扩至R=1000以上,但前提是机械水表要有良好的测量重复性、长期工作的稳定性,以及很高的测量灵敏阈。文章介绍了宽量程垂直螺翼式水表旋转量转换原理和水表误差特性的校正方法,使新研制的水表性能指标达到了较高水平。 展开更多
关键词 仪表系数 流量测量特性 特性校正技术 垂直螺翼式水表 管道水流量测量
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泊肃叶定律的实验验证
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作者 许敏舒 《中国医学物理学杂志》 CSCD 1991年第Z1期100-100,共1页
用一根很长的半径为r_o的圆截面水平管道,其进口与出口连通巨大的水箱,使管道两端之间的压强保持不变,提供管道水流作定常流的条件。从进口开始,每隔等距离开一个侧孔,并分别接到一组压力计上,测出水流沿管道的压力梯度ΔP/L。实验表明... 用一根很长的半径为r_o的圆截面水平管道,其进口与出口连通巨大的水箱,使管道两端之间的压强保持不变,提供管道水流作定常流的条件。从进口开始,每隔等距离开一个侧孔,并分别接到一组压力计上,测出水流沿管道的压力梯度ΔP/L。实验表明;在远离进口区的压力随距离线性下降,即ΔP/L是常数。另外。 展开更多
关键词 泊肃叶定律 管道水流 压力梯度 圆截面 水平管道 定常流 线性下降 小液滴 速度剖面 粘滞系数
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Experimental Study on the Distribution of Velocity and Pressure near a Submarine Pipeline 被引量:2
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作者 HAN Yan SHI Bing REN Xingyue JING Xiaodong 《Journal of Ocean University of China》 SCIE CAS 2009年第4期404-408,共5页
As a transport means of oil and gas the submarine pipeline has many merits, such as continuous delivery, large conveying capacity, convenient management, etc. A tube was chosen in our study to simulate the submarine p... As a transport means of oil and gas the submarine pipeline has many merits, such as continuous delivery, large conveying capacity, convenient management, etc. A tube was chosen in our study to simulate the submarine pipeline in the experiments. A high accuracy instrument ADV and high precision point-type pressure sensors were used to measure the parameters of the flow field, including the pressure distribution, velocities at seven cross sections near the submarine pipeline with five different clearance ratios, and twelve dynamic pressure values around the pipeline. The pressure distributions and velocity changes around the pipe under dif- ferent flow velocities and clearance ratios were analyzed. These results might be useful for further study of submarine pipeline ero- sion and protection. 展开更多
关键词 submarine pipeline velocity field pressure distribution EXPERIMENT
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Experimental Research on Gas-Liquid Two-Phase Spiral Flow in Horizontal Pipe 被引量:8
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作者 Wang Shuli Rao Yongchao +1 位作者 Wu Yuxian Wang Xiaobing 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第3期24-32,共9页
In view of the importance of gas-liquid two-phase spiral flow and the few research reports at home and abroad,the gas-liquid two-phase spiral flow patterns have been researched in a horizontal pipe with different para... In view of the importance of gas-liquid two-phase spiral flow and the few research reports at home and abroad,the gas-liquid two-phase spiral flow patterns have been researched in a horizontal pipe with different parameters investigated by means of observation and a high-speed camera.Since the appearance of spiral flow makes the distribution of twophase flow more complicated,the flow patterns appearing in the experiments were divided into the Spiral Wavy Stratified Flow(SWS),the Spiral Bubble Flow(SB),the Spiral Slug Flow(SS),the Spiral Linear Flow(SL),the Spiral Axial Flow(SA),and the Spiral Dispersed Flow(SD) by the observations and with reference to the predecessors' research achievements.A flow pattern map has been drawn up.The influence of velocity,vane angle and vane area on flow pattern conversion boundary and pressure drop has been studied,with a solid foundation laid for the future research work. 展开更多
关键词 gas-liquid two-phase spiral flow VANE flow pattern flow pattern map experimental research
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A Preliminary Study on Hydrate Anti-agglomerant Applied in Multiphase Flow Pipeline 被引量:1
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作者 Haiyuan Yao Qingping Li +1 位作者 Guangjin Chen Jing Gong 《Journal of Energy and Power Engineering》 2013年第2期266-271,共6页
When new types of hydrate chemical inhibitor (such as hydrate anti-agglomerant) are used in offshore fields, some difficulties will be encountered in the pipe transportation processing design. In view of these diffi... When new types of hydrate chemical inhibitor (such as hydrate anti-agglomerant) are used in offshore fields, some difficulties will be encountered in the pipe transportation processing design. In view of these difficulties, a horizontal flow experiment pipe loop of transparent polypropylene pipe (25.4 mm inner diameter, 20 m long) was constructed, and some experiments were conducted. The working fluids were the mixed paraffin hydrocarbons, water and condensate oil mixtures obtained from offshore oil field. Analyzing the experimental results and adopting relevant theories of liquid-solid two-phase flow, the computational method of hydrate slurry transportation in pipe was developed. For the operating conditions of a certain multiphase pipeline, by using OLGA software, this method can be used to calculate pressure drop of the multiphase flow pipelines using anti-agglomerant, which can provide support for hydrate anti-agglomerant application. 展开更多
关键词 HYDRATE SLURRY pressure drop multiphase flow.
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Influence of Nonionic Surfactant Addition on Drag Reduction of Water Based Nanofluid in a Small Diameter Pipe 被引量:1
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作者 Micha Drzazga Andrzej Gierczycki +1 位作者 Grzegorz Dzido Marcin Lemanowicz 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第1期104-108,共5页
The goal of this research was to determine the impact of nonionic surfactants on drag reduction effect in water and metal oxide nanofluid. Two nonionic surfactants (Rokacet 07 and Rokanol KT) and copper(II) oxide ... The goal of this research was to determine the impact of nonionic surfactants on drag reduction effect in water and metal oxide nanofluid. Two nonionic surfactants (Rokacet 07 and Rokanol KT) and copper(II) oxide wa- ter-based nanofluid were examined. Friction factors in a 4 mm diameter pipe for the Reynolds number between 8000 and 50000 were determined. Results showed that addition of nonionic surfactants caused the decrease of fric- tion factor in water and nanofluid. The drag reduction effect was similar in both cases. Presence of nanoparticles in the system has no great influence on drag reduction effect. 展开更多
关键词 NANOFLUID nonionic surfactant drag reduction
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Three-phase flow of submarine gas hydrate pipe transport 被引量:7
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作者 李立 徐海良 杨放琼 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第9期3650-3656,共7页
In the hydraulic transporting process of cutter-suction mining natural gas hydrate, when the temperature-pressure equilibrium of gas hydrate is broken, gas hydrates dissociate into gas. As a result, solid-liquid two-p... In the hydraulic transporting process of cutter-suction mining natural gas hydrate, when the temperature-pressure equilibrium of gas hydrate is broken, gas hydrates dissociate into gas. As a result, solid-liquid two-phase flow(hydrate and water) transforms into gas-solid-liquid three-phase flow(methane, hydrate and water) inside the pipeline. The Euler model and CFD-PBM model were used to simulate gas-solid-liquid three-phase flow. Numerical simulation results show that the gas and solid phase gradually accumulate to the center of the pipe. Flow velocity decreases from center to boundary of the pipe along the radial direction. Comparison of numerical simulation results of two models reveals that the flow state simulated by CFD-PBM model is more uniform than that simulated by Euler model, and the main behavior of the bubble is small bubbles coalescence to large one. Comparison of numerical simulation and experimental investigation shows that the values of flow velocity and gas fraction in CFD-PBM model agree with experimental data better than those in Euler model. The proposed PBM model provides a more accurate and effective way to estimate three-phase flow state of transporting gas hydrate within the submarine pipeline. 展开更多
关键词 gas hydrate pipe transport three-phase flow Euler model CFD-PBM model
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Experimental Acoustic Determination of the Void Fraction in Two-Phase Flow in Horizontal Pipelines
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作者 Fernando Augusto de Noronha Castro Pinto Thiago de Campos Negrelly Alexandre Silva de Lima 《Journal of Mechanics Engineering and Automation》 2014年第8期625-631,共7页
In multi-phase flows, the phases can flow and arranged in different spatial configurations in the pipe, which called flow patterns. This type of flow is found in the oil, chemical and nuclear industries. For example, ... In multi-phase flows, the phases can flow and arranged in different spatial configurations in the pipe, which called flow patterns. This type of flow is found in the oil, chemical and nuclear industries. For example, in the production and transport of oil and gas, the identification of the flow patterns are essential for answering those questions which are related to the economic return of the field, such as, measuring the volumetric flow, determining the pressure drop along the flow lines, production management and supervision. In offshore production, these factors are very important. This paper presents a new method for measuring the void fraction in horizontal pipelines, taking the air as gas in water-air two-phase flow. Through acoustic analysis of the frequency response of the pipe, the method gets the parameters to changes in runoff regime, in an experimental arrangement constructed on a small scale. The main advantages are the non-intrusive characteristic and easy to implement. The paper is composed of a qualitative experimental evaluation and transducers (microphone) which are used to analyze variations in the response accompanying variations in void and flow pattern changes. Changes are imposed and controlled by a two-phase flow experimental simulation rig, including a measurement cell constituted of an external casing that can isolate the measurement from the environmental background noise fitted with acoustic pressure transducers radially arranged, and the impact of a monitored excitation mechanism. The signals which captured by the microphones are processed and analyzed by checking their frequency contents changes according to the amount of air in the mixture. 展开更多
关键词 Experimental method two-phase flow determination of void fraction horizontal pipelines.
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Numerical Prediction of Flow Patterns after Various Pipe Fittings
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作者 Andreas Swienty Raja Abou Ackl Paul Uwe Thamsen 《Journal of Mechanics Engineering and Automation》 2015年第10期542-548,共7页
An accurate prediction of flows using CFD depends on a large number of factors. In addition to discretizing the flow region, the correct definition of boundary or initial conditions and the choice of suitable numerica... An accurate prediction of flows using CFD depends on a large number of factors. In addition to discretizing the flow region, the correct definition of boundary or initial conditions and the choice of suitable numerical methods, the applied turbulence model influences the results of the flow simulation to a great extent. Therefore, a validation of the results with the experimental data is of great importance for a correct selection of a turbulence model. It is the scope of this paper to assess different turbulence models for the simulation of pipe flows. The calculation results of pipe flows through a combination of 90~ elbows and a 1/3 segmental orifice are compared with experimental measurement results. This has the advantage that the suitability of the turbulence models for simulating both shear and swirl flows can be investigated. Thus, the k-ω, k-ε model and the Launder Reece Rodi Reynolds stress model are compared with each other and experimental results. Furthermore, this investigation is extended through including a much more c detached-eddy simulation. This model provides better prediction of the flow by resolving the large eddies and modeling the small ones. The experimental results originate from LDV measurements over the entire pipe cross-section. This measuring method provides velocity vectors over the measured surface. 展开更多
关键词 CFD turbulence models k-ε k-ω LRR DES.
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岩溶管道和溶蚀裂隙示踪曲线特征室内实验对比研究 被引量:3
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作者 计顺顺 刘建刚 +3 位作者 吴悦 彭大伟 张斌龙 王美霞 《勘察科学技术》 2017年第4期11-14,25,共5页
前人对如何探明岩溶地下水流场类型、结构及性质做了大量的研究,特别在岩溶管道形态及组合与示踪曲线的对应关系上做了系统总结,但在岩溶管道和溶蚀裂隙的识别上尚需进一步研究。该文旨在研究岩溶管道和溶蚀裂隙在示踪实验和示踪曲线上... 前人对如何探明岩溶地下水流场类型、结构及性质做了大量的研究,特别在岩溶管道形态及组合与示踪曲线的对应关系上做了系统总结,但在岩溶管道和溶蚀裂隙的识别上尚需进一步研究。该文旨在研究岩溶管道和溶蚀裂隙在示踪实验和示踪曲线上的特征,设计了三组等截面积但不同截面形状的管道和裂隙示踪实验,通过分析对比实验得到示踪曲线特征,研究在一定条件下管道与裂隙中的水流形态与不同截面形状的关系,为岩溶调查时识别岩溶管道和溶蚀裂隙提供一定的依据。 展开更多
关键词 裂隙水流 管道水流 电导率 示踪曲线
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A mathematical model in closed for unsteady mixed flows water pipes Dedicated to the NSFC-CNRS Chinese-French summer institute on fluid mechanics in 2010
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作者 BOURDARIAS Christian ERSOY Mehmet GERBI Stephane 《Science China Mathematics》 SCIE 2012年第1期221-244,共24页
We present the formal derivation of a new unidirectional model for unsteady mixed flows in nonuniform closed water pipes. In the case of free surface incompressible flows, the FS-model is formally obtained, using form... We present the formal derivation of a new unidirectional model for unsteady mixed flows in nonuniform closed water pipes. In the case of free surface incompressible flows, the FS-model is formally obtained, using formal asymptotic analysis, which is an extension to more classical shallow water models. In the same way, when the pipe is full, we propose the P-model, which describes the evolution of a compressible inviscid flow, close to gas dynamics equations in a nozzle. In order to cope with the transition between a free surface state and a pressured (i.e., compressible) state, we propose a mixed model, the PFS-model, taking into account changes of section and slope variation. 展开更多
关键词 shallow water equations unsteady mixed flows free surface flows pressurized flows curvilinear transformation asymptotic analysis
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The effect of evaporator operating parameters on the flow patterns inside horizontal pipes
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作者 Lige Tong Haiyan Li Li Wang Xinxing Sun Yunfei Xie 《Journal of Thermal Science》 SCIE EI CAS CSCD 2011年第4期324-331,共8页
A general and simple model for simulating the steady state behaviors of Mr-m-refrigerant fin-and-tube evaporator is introduced with the focus on the detailed flow patterns inside the tubes. In order to simulate the he... A general and simple model for simulating the steady state behaviors of Mr-m-refrigerant fin-and-tube evaporator is introduced with the focus on the detailed flow patterns inside the tubes. In order to simulate the heat transfer between air and the working fluid, the evaporator is divided into a number of control volumes. Empirical correlations from literature were also adopted to estimate the void fraction, the internal and external heat transfer coefficients, and the pressure drops. Simulations were performed to study the effects of varying inlet air temperature, refrigerant mass flow rate and evaporation pressure on the flow patterns inside the horizontal pipe of the evaporator. The simulation results indicate that the proposed model can be used to predict flow patterns well. The predicted results of the model agree well with experimental results, the difference is within ±3% for the cooling capacity, and is within ±0.2% for refrigerant evaporation temperature. 展开更多
关键词 EVAPORATOR distributed model two-phase zone flow pattern
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