scholarly journals Mechanics of advection of suspended particles in turbulent flow

2016 ◽  
Vol 472 (2195) ◽  
pp. 20160749 ◽  
Author(s):  
Sk Zeeshan Ali ◽  
Subhasish Dey
Keyword(s):  
Solid Particle ◽  
Particle Concentration ◽  
Two Phase Flow ◽  
Dynamic Equilibrium ◽  
Flow System ◽  
Suspended Solid ◽  
Reference Level ◽  
Phase Flow ◽  
Two Phase ◽  
Rouse Number

In this paper, we explore the mechanics and the turbulent structure of two-phase (fluid–solid particle) flow system, for the first time, by considering the dynamic equilibrium coupled with suspended solid particle concentration, fluid flow and energetics of the two-phase flow system. The continuity, momentum and turbulent kinetic energy (TKE) equations of the fluid and the solid phases are treated separately to derive a generalized relationship of the two-phase flow system aided by suitable closure relationships. The results obtained from the numerical solution of resulting equations show that the particle concentration and the TKE diminish with an increase in the Rouse number, while the horizontal velocity component increases. On the other hand, the TKE flux, diffusion and production rates increase with an increase in the Rouse number, while the TKE dissipation rate decreases. In the vicinity of the reference level (that is, the hypothetical level from which the particles come in suspension), the Kolmogorov number increases with an increase in the Rouse number. However, as the vertical distance increases, this behaviour becomes reverse. A close observation of the turbulent length scales reveals that the Prandtl's mixing length decreases with an increase in the Rouse number, but the Taylor microscale and the Kolmogorov length scale increase.

Visualizing Test on the Distribution Rule of Coarse Particles in a Double Blade Pump

2019 ◽  
Author(s):  
Xianfang Wu ◽  
Xiao Tian ◽  
Minggao Tan ◽  
Houlin Liu
Keyword(s):  
Particle Concentration ◽  
Two Phase Flow ◽  
Particle Density ◽  
Particle Diameter ◽  
Phase Flow ◽  
Coarse Particles ◽  
Two Phase ◽  
Solid Liquid ◽  
Blade Pump ◽  
Flow Pump

Abstract As a typical fluid mechanics problem, pump blockage has always been a hot research topic. The obtaining of the distribution of coarse particles in the solid-liquid two-phase flow pump is the basis of improving its non-blocking performance. High-speed photography technique is applied to do visualizing test and research on the distribution of coarse particles in a double blade pump. The effects of particle concentration, particle density and particle diameter on the distribution of coarse particles in the solid-liquid two-phase flow pump at different phases are studied. Besides, the variation of hydraulic performance of the double blade pump under different parameters is also analyzed. The results show that the particles in the impeller mainly located in the vicinity of the blade pressure surface, and the distribution of the particles in each section of the volute is quite different. The great difference in particle density can result in obviously uneven distribution of particles. With the increase of particle diameter, particle density and particle concentration, the pump head and efficiency both decrease while the shaft power increase on the contrary. This research results can also provide a basis for the optimization design of solid-liquid two-phase flow pumps.

Experimental and Numerical Study on Solid Particle Erosion in Elbows Mounted in Series

2017 ◽  
Author(s):  
Alireza Asgharpour ◽  
Peyman Zahedi ◽  
Hadi Arabnejad Khanouki ◽  
Siamack A. Shirazi ◽  
Brenton S. McLaury
Keyword(s):  
Solid Particle ◽  
Two Phase Flow ◽  
Numerical Study ◽  
Flow Direction ◽  
Solid Particle Erosion ◽  
Phase Flow ◽  
Particle Erosion ◽  
Two Phase ◽  
Experimental Conditions ◽  
In Series

Solid particle erosion in elbows is of great importance in the pipeline design process. In many situations, elbows are mounted in series with small distances between each other. Due to changes in flow direction and particles concentration after the first elbow, a significant change in erosion magnitude and pattern in the downstream elbows (second elbow) might be expected. The aim of this study is to investigate the solid particle erosion behavior in the second elbow. In the experimental study using a state-of-art ultrasonic technique, erosion magnitudes in two standard 4-inch elbows separated by a distance of 10 pipe diameter have been measured. Experiments have been conducted in single and two-phase flow regimes for different particle sizes and gas and liquid velocities. In most of the cases, the maximum erosion in the second elbow was less than the first elbow, and the erosion pattern in the second elbow was slightly different than the first elbow. Comparison of single and two-phase flow results for both elbows revealed that in two-phase flow regime a major reduction in erosion magnitude happens as a results of the presence of liquid in the pipe. Additionally, for further considerations, the experimental conditions have been simulated numerically using ANSYS FLUENT software. Simulations have been performed for different mesh grids and turbulence models to examine how they influence the erosion in the second elbow as both can affect the particles trajectories. The accuracy of the numerical results are evaluated with available experimental data. For most of the cases, the erosion predictions are in a good agreement with experimental results. For both elbows by increasing the gas velocity and particle size, the maximum erosion increased.

scholarly journals Numerical simulation of predicting and reducing solid particle erosion of solid-liquid two-phase flow in a choke

2009 ◽  
Vol 6 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Guomei Li ◽  
Yueshe Wang ◽  
Renyang He ◽  
Xuewen Cao ◽  
Changzhi Lin ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Solid Particle ◽  
Two Phase Flow ◽  
Solid Particle Erosion ◽  
Phase Flow ◽  
Particle Erosion ◽  
Two Phase ◽  
Solid Liquid

scholarly journals A Numerical Model of Tracer Transport in a Non-isothermal Two-Phase Flow System for $${\text{ CO}}_2$$ Geological Storage Characterization

2013 ◽  
Vol 98 (1) ◽  
pp. 173-192 ◽  
Author(s):  
Fuguo Tong ◽  
Auli Niemi ◽  
Zhibing Yang ◽  
Fritjof Fagerlund ◽  
Tobias Licha ◽  
...  
Keyword(s):  
Numerical Model ◽  
Two Phase Flow ◽  
Flow System ◽  
Phase Flow ◽  
Geological Storage ◽  
Tracer Transport ◽  
Two Phase

scholarly journals A two-phase flow model of sediment transport: transition from bedload to suspended load

2014 ◽  
Vol 755 ◽  
pp. 561-581 ◽  
Author(s):  
Filippo Chiodi ◽  
Philippe Claudin ◽  
Bruno Andreotti
Keyword(s):  
Sediment Transport ◽  
Flow Model ◽  
Two Phase Flow ◽  
Suspended Load ◽  
Particle Migration ◽  
Turbulent Shear ◽  
Phase Flow ◽  
Dimensionless Numbers ◽  
Two Phase ◽  
Rouse Number

AbstractThe transport of dense particles by a turbulent flow depends on two dimensionless numbers. Depending on the ratio of the shear velocity of the flow to the settling velocity of the particles (or the Rouse number), sediment transport takes place in a thin layer localized at the surface of the sediment bed (bedload) or over the whole water depth (suspended load). Moreover, depending on the sedimentation Reynolds number, the bedload layer is embedded in the viscous sublayer or is larger. We propose here a two-phase flow model able to describe both viscous and turbulent shear flows. Particle migration is described as resulting from normal stresses, but is limited by turbulent mixing and shear-induced diffusion of particles. Using this framework, we theoretically investigate the transition between bedload and suspended load.

Continuous cell partitioning using an aqueous two-phase flow system in microfluidic devices

2004 ◽  
Vol 88 (4) ◽  
pp. 489-494 ◽  
Author(s):  
Masumi Yamada ◽  
Vivi Kasim ◽  
Megumi Nakashima ◽  
Jun'ichi Edahiro ◽  
Minoru Seki
Keyword(s):  
Two Phase Flow ◽  
Flow System ◽  
Microfluidic Devices ◽  
Phase Flow ◽  
Two Phase ◽  
Cell Partitioning
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