Influence of Pipeline Inclination on Hydraulic Conveying of Sand Particles

2012 ◽  
Author(s):  
Ahmed Mohamed Nossair ◽  
Peter Rodgers ◽  
Afshin Goharzadeh
Keyword(s):  
Particle Transport ◽  
High Speed ◽  
Sand Dune ◽  
Sand Particle ◽  
Hydrocarbon Production ◽  
Production Wells ◽  
Load Transport ◽  
Bed Load Transport ◽  
Sand Particles ◽  
Dune Dynamics

The understanding of sand particle transport by fluids in pipelines is of importance for the drilling of horizontal and inclined hydrocarbon production wells, topside process facilities, infield pipelines, and trunk lines. Previous studies on hydraulic conveying of sand particles in pipelines have made significant contributions to the understanding of multiphase flow patterns, pressure drop and particle transport rate in horizontal pipelines. However, due to the complexity of the flow structure resulting from liquid-sand interactions, the mechanisms responsible for bed-load transport flow for hydraulic conveying of sand particles have not been extensively studied in inclined pipelines. This paper presents an experimental investigation of hydraulic conveying of sand particles resulting from a stationary flat bed in both horizontal and +3.6 degree upward inclined pipelines. The characteristics of sand transportation by saltation from an initial sand bed are experimentally visualized using a transparent Plexiglas pipeline and high-speed digital photography. The dune formation process is assessed as a function of pipeline orientation. Based on the visualized dune morphology, pipeline inclination is found to have a significant influence on hydraulic conveying of sand dune dynamics (i.e., dune velocity), as well as sand dune geometry (i.e., dune pitch and characteristic dune angles).

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.

scholarly journals A microstructural approach to bed load transport: mean behaviour and fluctuations of particle transport rates

2014 ◽  
Vol 744 ◽  
pp. 129-168 ◽  
Author(s):  
C. Ancey ◽  
J. Heyman
Keyword(s):  
Steady State ◽  
Particle Transport ◽  
Particle Flux ◽  
Master Equations ◽  
Bed Load ◽  
Governing Equations ◽  
Macroscopic Scale ◽  
Load Transport ◽  
Bed Load Transport ◽  
The Continuum

AbstractThis paper concerns a model of bed load transport, which describes the advection and dispersion of coarse particles carried by a turbulent water stream. The challenge is to develop a microstructural approach that, on the one hand, yields a parsimonious description of particle transport at the microscopic scale and, on the other hand, leads to averaged equations at the macroscopic scale that can be consistently interpreted in light of the continuum equations used in hydraulics. The cornerstone of the theory is the proper determination of the particle flux fluctuations. Apart from turbulence-induced noise, fluctuations in the particle transport rate are generated by particle exchanges with the bed consisting of particle entrainment and deposition. At the particle scale, the evolution of the number of moving particles can be described probabilistically using a coupled set of reaction–diffusion master equations. Theoretically, this is interesting but impractical, as solving the governing equations is fraught with difficulty. Using the Poisson representation, we show that these multivariate master equations can be converted into Fokker–Planck equations without any simplifying approximations. Thus, in the continuum limit, we end up with a Langevin-like stochastic partial differential equation that governs the time and space variations of the probability density function for the number of moving particles. For steady-state flow conditions and a fixed control volume, the probability distributions of the number of moving particles and the particle flux can be calculated analytically. Taking the average of the microscopic governing equations leads to an average mass conservation equation, which takes the form of the classic Exner equation under certain conditions carefully addressed in the paper. Analysis also highlights the specific part played by a process we refer to as collective entrainment, i.e. a nonlinear feedback process in particle entrainment. In the absence of collective entrainment the fluctuations in the number of moving particles are Poissonian, which implies that at the macroscopic scale they act as white noise that mediates bed evolution. In contrast, when collective entrainment occurs, large non-Poissonian fluctuations arise, with the important consequence that the evolution at the macroscopic scale may depart significantly that predicted by the averaged Exner equation. Comparison with experimental data gives satisfactory results for steady-state flows.

Numerical Simulation of Behavior of Sand Particles during High-Speed Penetration with Particle Method

2016 ◽  
Vol 715 ◽  
pp. 198-202
Author(s):  
Ryota Shimono ◽  
Keiko Watanabe
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Free Particle ◽  
Particle Method ◽  
Particle Methods ◽  
Sand Particle ◽  
Mesh Free ◽  
Research Themes ◽  
Macro Scale ◽  
Sand Particles

The phenomena that occur during high-speed penetration of a projectile into sand particles are interesting subjects in engineering. The macro-scale research themes are the behavior of the ejected sand particles and the progress of the high-speed projectile, while the micro-scale research themes are the deformation and fragmentation of a single sand particle. Studies of these unique phenomena were conducted using both experiments and numerical simulation. Although accurate simulation of the behavior of sand particles during high-speed penetration is difficult because sand particles have characteristics of both fluids and solids, the reproducibility of the actual phenomena has improved in recent years with the development of particle methods. In our research, we conducted simulations of the phenomena using Smoothed Particle Hydrodynamics (SPH), which is a mesh-free, particle-based method. The results showed the possibility of accurate reproduction during high-speed projectile penetration into sand particles at the macro-scale.

Experimental study on the high-speed impact of a sand particle on Ti–6Al–4V

2019 ◽  
Vol 234 (4) ◽  
pp. 632-646
Author(s):  
Cheng Yan ◽  
Wei Chen ◽  
Zhenhua Zhao
Keyword(s):  
High Speed ◽  
Impact Damage ◽  
Damage Mechanism ◽  
Impact Angle ◽  
Sand Particle ◽  
Compressor Blades ◽  
Supersonic Airflow ◽  
High Speed Impact ◽  
Sand Particles ◽  
The Impact

When sand is ingested by a helicopter engine, it collides with the compressor blades at a high relative speed, causing severe erosion damage. A test was conducted on the high-speed impact of sand particles on the target of Ti–6Al–4 V alloy to enhance the understanding of high-speed impact damage mechanism. The test apparatus was used to create supersonic airflow, which was produced by normal temperature air flowing through a special Laval nozzle. The supersonic airflow produced the drag force to increase the velocity of sand particles up to about 400 m/s. The experiment demonstrated that fractured sand particle caused less damage than nonfractured particle under similar impact conditions. The nonfractured particle directly cut the target more easily than the fractured at a relatively low impact velocity. When the impact speed exceeded 300 m/s, the crater depth increased exponentially with the increase of velocity. Impact angle determined the mode of material failure.

Influence of Slug Flow on Hydraulic Sand Dune Migration in Horizontal Pipelines

2008 ◽  
Author(s):  
Afshin Goharzadeh ◽  
Peter Rodgers ◽  
Chokri Touati
Keyword(s):  
Slug Flow ◽  
High Speed ◽  
Sand Dune ◽  
Front Velocity ◽  
Sand Particle ◽  
Horizontal Pipe ◽  
Particle Mobility ◽  
Three Phase ◽  
Slug Flows ◽  
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 slug flow. Sand dune pitch, 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 slug 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 slug flows. The sand dune local velocity (inside the slug body) was measured to be three times higher than the averaged dune velocities.

scholarly journals Wind-Tunnel Studies on Sand Sedimentation Around Wind-Break Walls of Lanxin High-Speed Railway II and Its Prevention

2021 ◽  
Vol 11 (13) ◽  
pp. 5989
Author(s):  
Hongchao Dun ◽  
Guowei Xin ◽  
Ning Huang ◽  
Guangtian Shi ◽  
Jie Zhang
Keyword(s):  
Wind Tunnel ◽  
Deposition Rate ◽  
High Speed ◽  
Particle Deposition ◽  
Sand Particle ◽  
Gobi Desert ◽  
Strong Wind ◽  
Number Density ◽  
High Speed Railway ◽  
Sand Particles

Wind-break walls along Lanxin High-Speed Railway II were studied and approved as effective measures to reduce strong wind damage to the high-speed trains. The results show that sand sedimentation on the leeward sides of wind-break walls along the railway within Gobi Desert could significantly threaten the operation safety of running trains. Different from the current sand sedimentation prevention measures without adequate consideration of the deposition process of airborne sand particles, this study revealed the mechanism of sand sedimentation on the leeward sides of three wind-break walls within different terrains. A series of wind-tunnel experiments were carried out to measure the horizontal velocity, number density, transport flux, and deposition rate of sand particles, and it was found that the horizontal speed of sand particles was first increased and then decreased on the railway track, and the peak speed over the concave subgrade was much smaller than those over convex and flat subgrades. The number density and horizontal sand flux were largest over the concave subgrade, and were the smallest over the convex subgrade. The sand particle deposition rate and distribution were also the largest within the concave subgrade, and some measures were also proposed to prevent sand sedimentation on the leeward sides of wind-break walls.

scholarly journals Basset force in numerical models of saltation / Bassetova síla v numerických modelech saltace částic

2012 ◽  
Vol 60 (4) ◽  
pp. 277-287 ◽  
Author(s):  
Nikolay Lukerchenko ◽  
Jindrich Dolansky ◽  
Pavel Vlasak
Keyword(s):  
Particle Motion ◽  
Numerical Models ◽  
Sand Particle ◽  
Particle Collisions ◽  
Main Mode ◽  
Basset Force ◽  
Load Transport ◽  
Bed Load Transport ◽  
History Force ◽  
Particle Bed

In numerical models of fluid flow with particles moving close to solid boundaries, the Basset force is usually calculated for the particle motion between particle-boundary collisions. The present study shows that the history force must also be taken into account regarding particle collisions with boundaries or with other particles. For saltation - the main mode of bed load transport - it is shown using calculations that two parts of the history force due to both particle motion in the fluid and to particle-bed collisions are comparable and substantially compensate one another. The calculations and comparison of the Basset force with other forces acting on a sand particle saltating in water flow are carried out for the different values of the transport stage. The conditions under which the Basset force can be neglected in numerical models of saltation are studied.

NUMERICAL MODEL TO SIMULATE THE EROSION ON THE SLOPE DUE TO OVERTOPPING

2010 ◽  
Vol 13 (3) ◽  
pp. 78-87
Author(s):  
Hoai Cong Huynh
Keyword(s):  
Numerical Model ◽  
Flow Model ◽  
Bed Load ◽  
Experiment Data ◽  
Step Method ◽  
Morphological Model ◽  
Load Transport ◽  
Bed Load Transport ◽  
The Finite Difference Method ◽  
Good Agreement

The numerical model is developed consisting of a 1D flow model and the morphological model to simulate the erosion due to the water overtopping. The step method is applied to solve the water surface on the slope and the finite difference method of the modified Lax Scheme is applied for bed change equation. The Meyer-Peter and Muller formulae is used to determine the bed load transport rate. The model is calibrated and verified based on the data in experiment. It is found that the computed results and experiment data are good agreement.

Experimental study on laminated glass responses of high-speed trains subject to windblown sand particles loading

2021 ◽  
Vol 300 ◽  
pp. 124332
Author(s):  
Gongxun Deng ◽  
Wen Ma ◽  
Yong Peng ◽  
Shiming Wang ◽  
Song Yao ◽  
...  
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
Laminated Glass ◽  
Windblown Sand ◽  
High Speed Trains ◽  
Sand Particles
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