scholarly journals Calculation of Hydraulic Resistance in the Case of a Diffuser and a Confuser in a Horizontal Pipe

2021 ◽  
Vol 137 (6) ◽  
pp. 62-64
Author(s):  
A. M. Khurmamatov ◽  
◽  
G. B. Rakhimov ◽  
Keyword(s):  
Hydraulic Resistance ◽  
Pressure Loss ◽  
Head Loss ◽  
Sudden Expansion ◽  
Horizontal Pipe ◽  
Rate Of Increase ◽  
Inner Diameter

The main results of the calculation of the head loss with a smooth expansion and narrowing of the horizontal pipe, which has the following geometric dimensions; - the inner diameter of the pipe with a narrowing of 25 mm and an expansion of 50 mm. The pressure loss of the smooth expansion of the pipe at an oil velocity of 0.2–1.0 m/s has a smooth rate of increase from 0.002 to 0.032 m. With a smooth narrowing of the pipe, the head loss is from 0.0021 to 0.024 m. That, during the movement of oil in a horizontal pipe, the head loss with a sudden expansion is 1.33 times greater than that of a sudden narrowing.

scholarly journals Experimental and Numerical analysis of Flow characteristics of sand water slurry in a horizontal pipe

2021 ◽  
Author(s):  
Varinder Singh ◽  
◽  
Satish Kumar ◽  
Dwarikanath Ratha ◽  
◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Pressure Loss ◽  
Volume Fraction ◽  
Head Loss ◽  
Experimental Results ◽  
Solid Concentration ◽  
Horizontal Pipe ◽  
Slurry Concentration ◽  
Water Slurry ◽  
Test Loop

The transportation of the solid material using hydraulic transportation method is economically the best method. The head loss occurs during transportation of slurry through horizontal pipelines usually depends on the rheological behavior of slurry, slurry concentration, particle size, and influx velocity. An experimental investigation has been performed using sand-water slurry flowing through the horizontal pipe section of a pilot plant test loop. The head loss obtained from the experimental results was validated through CFD simulation using FLUENT. The solid concentration of sand-water slurry and influx velocity used during both experiments and numerical simulation were in the range of 10-40% (by weight) and 1 to 4 m/s respectively. The numerical simulations were performed using five different turbulence models and the results obtained using SST k-omega model was in close agreement with experimental results. It is observed from both the experiment and numerical analysis that the pressure loss, granular pressure, volume fraction and skin fraction coefficient during transportation of slurry through a horizontal pipe is a function of solid concentration and influx velocity. The present study observed that as the flow velocity increases four times, the pressure loss is increasing more than 10 times. Uniform volume fraction at middle zone of outlet of the pipe is observed as both the slurry concentration and velocity of flow increases.

Computational and theoretical research of the injector block function

2020 ◽  
pp. 123-126
Author(s):  
В.В. Кожемякин ◽  
Р.А. Иванов ◽  
Е.С. Игнатьева
Keyword(s):  
Hydraulic Resistance ◽  
Cross Section ◽  
Flow Rate ◽  
Pressure Dependence ◽  
Theoretical Study ◽  
Water Jet ◽  
Theoretical Research ◽  
Sudden Expansion ◽  
Operating Modes ◽  
Coefficient Of Hydraulic Resistance

Работа посвящена расчетно-теоретическому исследованию работы блока инжекторов. Рассмотрен пароводяной струйный аппарат, который применяется в качестве средства циркуляции теплоносителя первого контура. Подвод дополнительного потока осуществляется на цилиндрическом участке с внезапным расширением сечения через перемычку. Для достижения поставленной цели разработана программа для ЭМВ, в которой смоделирована зависимость давления от нагрузки в контуре, а также проведено расчетно-теоретическое исследование влияние гидравлического сопротивления на расход перемычки. В данной работе рассмотрены только рабочие режимы, т.е. все инжекторы работают как насосы. В ходе работы было установлено, что при нагрузке в 30% увеличиваются коэффициенты инжекции пароводяного струйного аппарата, но характер работы перемычек не меняется. Так же было установлено, что расход через перемычку меняется не пропорционально коэффициенту гидравлического сопротивления перемычки. The paper is devoted to the computational and theoretical study of the injector block operation. A steam-water jet apparatus is considered, which is used as a means of circulating the primary circle coolant. The additional flow is supplied on the cylindrical section with a sudden expansion of the cross-section through the bridge. To achieve this goal, a computer program was developed that modeled the pressure dependence on the load in the circuit, and also a theoretical study of the influence of hydraulic resistance on the flow of the jumper was conducted. In this paper, only operating modes are considered, i.e. all the injectors function as pumps. In the process of the research, it was found that at a load of 30%, the injection coefficients of the steam-water jet apparatus increase, but the nature of the work of the jumpers does not change. It was also found out that the flow rate through the jumper does not change in proportion to the coefficient of hydraulic resistance of the jumper.

scholarly journals Effect of the Flame Dome Depth and Improvement of the Pressure Loss in the Dump Diffuser

1998 ◽  
Author(s):  
Shinji Honami ◽  
Wataru Tsuboi ◽  
Takaaki Shizawa
Keyword(s):  
Velocity Profile ◽  
Reynolds Stress ◽  
Flow Rate ◽  
Pressure Loss ◽  
Total Pressure ◽  
Flow Behavior ◽  
Sudden Expansion ◽  
Mean Velocity ◽  
The Mean ◽  
Stress Profiles

This paper presents the effect of flame dome depth on the total pressure performance and flow behavior in a sudden expansion region of the combustor diffuser without flow entering the dome head. The mean velocity and turbulent Reynolds stress profiles in the sudden expansion region were measured by a Laser Doppler Velocitmetry (LDV) system. The experiments show that total pressure loss is increased, when flame dome depth is increased. Installation of an inclined combuster wall in the sudden expansion region is suggested from the viewpoint of a control of the reattaching flow. The inclined combustor wall is found to be effective in improvement of the diffuser performance. Better characteristics of the flow rate distribution into the branched channels are obtained in the inclined wall configuration, even if the distorted velocity profile is provided at the diffuser inlet.

Simulation of Intermittent Flow Development in a Horizontal Pipe

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Hamed Nasrfard ◽  
Hassan Rahimzadeh ◽  
Ali Ahmadpour ◽  
Ehsan Amani
Keyword(s):  
Three Dimensional ◽  
Intermittent Flow ◽  
Horizontal Pipe ◽  
Vof Model ◽  
New Findings ◽  
Air Water Interface ◽  
Elongated Bubble ◽  
Bubble Length ◽  
Computational Fluid Dynamics Cfd ◽  
Inner Diameter

In this study, detailed three-dimensional (3D) numerical simulations of intermittent multiphase flows were carried out to investigate the slug initiation process and various features of intermittent flows inside a horizontal pipe. Air and water are used as working fluids. The domain used for simulations is a 14.4 m long pipe with 54 mm inner diameter. The volume of fluid (VOF) model was used to capture the air/water interface and its temporal evolution. Using the developed computational fluid dynamics (CFD) model, the slug formation and propagation along horizontal circular pipe were successfully predicted and studied comprehensively. Slug length and the frequency of slug formation, as two main features of intermittent flow, were used to validate the model against experimental results and available correlations in the literature. Three-dimensional numerical simulation of intermittent flow proved to be a powerful tool in tackling limitations of experiments and providing detailed data about various features of the intermittent flow. The effect of gas and liquid superficial velocities on the liquid slug and elongated bubble length was explored. Moreover, the study revealed new findings related to the elongated bubble shape and velocity field in the slug unit.

scholarly journals Experimental investigation of coarse particles-water mixture flow in horizontal and inclined pipes

2014 ◽  
Vol 62 (3) ◽  
pp. 241-247 ◽  
Author(s):  
Pavel Vlasák ◽  
Zdeněk Chára ◽  
Jan Krupička ◽  
Jiří Konfršt
Keyword(s):  
Dominant Mode ◽  
Solid Particles ◽  
Coarse Grained ◽  
Water Mixture ◽  
Mixture Flow ◽  
Horizontal Pipe ◽  
Pressure Drops ◽  
Steel Pipes ◽  
Inner Diameter ◽  
Inclined Pipes

Abstract The effect of solid concentration and mixture velocity on the flow behaviour, pressure drops, and concentration distribution of coarse particle-water mixtures in horizontal, vertical, and inclined smooth stainless steel pipes of inner diameter D = 100 mm was experimentally investigated. Graded basalt pebbles were used as solid particles. The study revealed that the coarse-grained particle-water mixtures in the horizontal and inclined pipes were significantly stratified. The solid particles moved principally in a layer close to the pipe invert; however for higher and moderate flow velocities, particle saltation became the dominant mode of particle conveyance. Frictional pressure drops in the horizontal pipe were found to be markedly higher than in the vertical pipe, while the frictional pressure drops in the ascending pipe increased with inclination angle up to about 30°.

scholarly journals Investigation for additional head loss in helically coiled flexible pipe of a mobile fertigation system

2018 ◽  
Vol 10 ◽  
pp. 01001
Author(s):  
Aliaksandr Basareuski
Keyword(s):  
Pressure Loss ◽  
Energy Intensity ◽  
Specific Energy Consumption ◽  
Head Loss ◽  
Theoretical Studies ◽  
Pipeline Transport ◽  
Flexible Pipe ◽  
System Parameters ◽  
Output Ratio ◽  
Fertilizer System

One of the major parameters of a hydraulic machine is its energy intensity, i.e. its power/output ratio. This article presents the results of theoretical studies of the effects of additional head loss of transporting fluid through helically coiled flexible pipe on specific energy consumption of fertigation machinery and pipeline transport. Computational methods have been used to determine that pressure loss will be 15-20% higher on the average than the loss at a straight section, depending on the average radius of coil helix/design pipe diameter ratio. Correlations have been obtained that allow for justification of major mobile fertilizer system parameters based on the need to minimize pressure loss.

The effect of certain biochemical factors on well clogging under suboxic and mildly anoxic conditions

2012 ◽  
Vol 65 (12) ◽  
pp. 2206-2212 ◽  
Author(s):  
M. Dimkić ◽  
M. Pušić ◽  
V. Obradović ◽  
S. Kovačević
Keyword(s):  
Redox Potential ◽  
Hydraulic Resistance ◽  
Iron Concentration ◽  
Research Project ◽  
Anoxic Conditions ◽  
Rate Of Increase ◽  
Well Clogging ◽  
Groundwater Source ◽  
Shed Light

Research conducted at the Belgrade Groundwater Source in Serbia has shown that significant well screen clogging processes take place under reduced oxic and initial anoxic conditions. Criteria for the prevention, or deceleration, of clogging are becoming more relevant to well ageing, compared with classical, mechanical clogging criteria and the permissible entrance velocities derived from them. The research project was later expanded to encompass other alluvial sources, which feature distinct oxic conditions. This paper presents some of the outcomes of this project, which shed light on the correlation between certain important indicators of well screen clogging (such as the redox potential and iron concentration) and the rate of increase in local hydraulic resistance at the wells.

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