Investigation of flow characteristics and eddy viscosity ratio for air-oil intermittent flow in horizontal pipe

2021 ◽  
Vol 35 (10) ◽  
pp. 4557-4564
Author(s):  
Santhosh Senguttuvan ◽  
Jun-Suk Youn ◽  
Hyeon-Seok Seo ◽  
Sung-Min Kim
Keyword(s):  
Eddy Viscosity ◽  
Viscosity Ratio ◽  
Flow Characteristics ◽  
Intermittent Flow ◽  
Horizontal Pipe

Influence of Gas-Liquid Two-Phase Intermittent Flow on Hydraulic Sand Dune Migration in Horizontal Pipelines

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Afshin Goharzadeh ◽  
Peter Rodgers ◽  
Chokri Touati
Keyword(s):  
High Speed ◽  
Sand Dune ◽  
Front Velocity ◽  
Intermittent Flow ◽  
Sand Particle ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Particle Mobility ◽  
Three Phase ◽  
Gas Ratio

This paper presents an experimental study of three-phase flows (air-water-sand) inside a horizontal pipe. The results obtained aim to enhance the fundamental understanding of sand transportation due to saltation in the presence of a gas-liquid two-phase intermittent flow. Sand dune pitch, length, height, and front velocity were measured using high-speed video photography. Four flow compositions with differing gas ratios, including hydraulic conveying, were assessed for sand transportation, having the same mixture velocity. For the test conditions under analysis, it was found that the gas ratio did not affect the average dune front velocity. However, for intermittent flows, the sand bed was transported further downstream relative to hydraulic conveying. It was also observed that the slug body significantly influences sand particle mobility. The physical mechanism of sand transportation was found to be discontinuous with intermittent flows. The sand dune local velocity (within the slug body) was measured to be three times higher than the averaged dune velocities, due to turbulent enhancement within the slug body.

Prediction of Flow Characteristics of Bimodal Slurry in Horizontal Pipe Flow

2008 ◽  
Vol 26 (4) ◽  
pp. 361-379 ◽  
Author(s):  
U. Kumar ◽  
S. N. Singh ◽  
V. Seshadri
Keyword(s):  
Pipe Flow ◽  
Flow Characteristics ◽  
Horizontal Pipe

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.

Pulverized-Coal Transport Through Pipes

1959 ◽  
Vol 81 (1) ◽  
pp. 43-52 ◽  
Author(s):  
R. C. Patterson
Keyword(s):  
Flow Characteristics ◽  
General Information ◽  
Pulverized Coal ◽  
Steam Generators ◽  
Test Program ◽  
Horizontal Pipe ◽  
Friction Factors ◽  
Piping Systems ◽  
Coal Mixtures

Some typical problems related to pulverized-coal transport for steam generators have been investigated in a long-term test program. The investigation has provided information relative to the performance of a commercial-type exhauster handling air-coal mixtures, friction factors for 8 and 12-in-diam pipe handling air-coal mixtures, general information as to the flow characteristics of air-coal mixtures in various piping systems, and methods and means for control of coal drifting in horizontal pipe. Friction factors in the range of 0.017 to 0.035 for 8 and 12-in. pipe are indicated for the usual operating range.

Research on the Pneumatic Conveying of the Sand in the Horizontal Pipe Based on FLUENT

2016 ◽  
Vol 11 (2) ◽  
pp. 159-165 ◽  
Author(s):  
Dan-yang Li ◽  
Shu Liu ◽  
Xiao-ning Wang
Keyword(s):  
Particle Diameter ◽  
Flow Characteristics ◽  
Axial Direction ◽  
Theoretical Research ◽  
Pneumatic Conveying ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Actual Measurement ◽  
Fluid Analysis ◽  
Euler Model

Abstract The pneumatic conveying experiment bed has been established to study the flow characteristics of air- solids two-phase flow in horizontal pipeline. Euler model was applied to simulate it based on analysis of Gambit and fluid analysis software-fluent. The simulated results indicated: under the same gas phase conveying flow and pressure, the bigger particle diameter is, the bigger pressure drop is in the horizontal pipeline. The smaller particle diameter is, the more uniform of the particle’s distribution is, and the more easily obtaining the acceleration is. Particle concentration at the bottom of the horizontal pipe is increasing in the axial direction, while close to the tail pipe it will be reduce. The simulated conclusion is consistent with the actual measurement results, herewith rendering some footing for engineering design and theoretical research on pneumatic conveying systems.

Drag-Reducing Flows in Laminar-Turbulent Transition Region

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Shu-Qing Yang ◽  
Donghong Ding
Keyword(s):  
Transition Region ◽  
Reynolds Shear Stress ◽  
Flow Characteristics ◽  
Physical Nature ◽  
Weighting Factor ◽  
Intermittent Flow ◽  
Mean Velocity ◽  
Turbulent Transition ◽  
Intermittency Factor ◽  
Laminar Turbulent Transition

This study makes an attempt to investigate Newtonian/non-Newtonian pipe flows in a laminar-turbulent transition region, which is an extraordinarily complicated process and is not fully understood. The key characteristic of this region is its intermittent nature, i.e., the flow alternates in time between being laminar or turbulent in a certain range of Reynolds numbers. The physical nature of this intermittent flow can be aptly described with the aid of the intermittency factor γ, which is defined as that fraction of time during which the flow at a given position remains turbulent. Spriggs postulated that a weighting factor can be used to calculate the friction factor, applying its values in laminar and turbulent states. Based on these, a model is developed to empirically express the mean velocity and Reynolds shear stress in the transition region. It is found that the intermittency factor can be used as a weighting factor for calculating the flow structures in the transition region. Good agreements can be achieved between the calculations and experimental data available in the literature, indicating that the present model is acceptable to express the flow characteristics in the transition region.

scholarly journals Experimental Study on Flow Characteristics of Ice-Water Slurries in a Horizontal Pipe.

1992 ◽  
Vol 108 (5) ◽  
pp. 357-363
Author(s):  
Hiroshi TAKAHASHI ◽  
Tadashi MASUYAMA ◽  
Toshio KAWASHIMA
Keyword(s):  
Experimental Study ◽  
Flow Characteristics ◽  
Horizontal Pipe ◽  
Ice Water
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