Asymmetric traps array for particle transport

RSC Advances ◽  
2015 ◽  
Vol 5 (5) ◽  
pp. 3358-3364 ◽  
Author(s):  
Jaesung Lee ◽  
Mark A. Burns
Keyword(s):  
Particle Transport ◽  
Flow Direction ◽  
Particle Interaction ◽  
Trap Particle

The asymmetric trap composed of three obstacles shows flow direction-dependent trap/particle interaction.

scholarly journals Simulation of Flexible Fibre Particle Interaction with a Single Cylinder

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 191
Author(s):  
Naser Hamedi ◽  
Lars-Göran Westerberg
Keyword(s):  
Reynolds Number ◽  
Shear Flow ◽  
Fibre Orientation ◽  
Flow Direction ◽  
Particle Interaction ◽  
Orientation Angle ◽  
Factors Affecting ◽  
Single Cylinder ◽  
Flow Past ◽  
Fibre Suspension

In the present study, the flow of a fibre suspension in a channel containing a cylinder was numerically studied for a very low Reynolds number. Further, the model was validated against previous studies by observing the flexible fibres in the shear flow. The model was employed to simulate the rigid, semi-flexible, and fully flexible fibre particle in the flow past a single cylinder. Two different fibre lengths with various flexibilities were applied in the simulations, while the initial orientation angle to the flow direction was changed between 45° ≤ θ ≤ 75°. It was shown that the influence of the fibre orientation was more significant for the larger orientation angle. The results highlighted the influence of several factors affecting the fibre particle in the flow past the cylinder.

Assessing sediment transport energetics with instrumented particles for above threshold of motion turbulent flows

2020 ◽  
Author(s):  
Zaid Al-Husban ◽  
Manousos Valyrakis
Keyword(s):  
Sediment Transport ◽  
Turbulent Flows ◽  
Particle Transport ◽  
Particle Interaction ◽  
Turbulent Channel Flow ◽  
Optimal Operation ◽  
Distribution Functions ◽  
Sensor Data ◽  
Flow Rates ◽  
Test Configuration

<p>Despite the fact sediment transport has been studied for decades, there is still a need to gain a further insight on the nature and driving mechanisms of bed particle motions induced by turbulent flows, for the low transport stages where the particle transport is relatively intermittent. A custom designed and prototyped instrumented particle, embedded with inertial sensors is used herein to study its transport over hydraulically rough bed surfaces. The calibration and error estimation for its sensors is also undertaken before starting the experiments, to ensure optimal operation and estimate any uncertainties.</p><p>The observations and results of this research are obtained from experiments carried out at the University of Glasgow 12 meters long and 0.9 meters wide, tilting and water recirculating flume. The flume walls comprise of smooth transparent glass that enables observing particle transport from the side (also with underwater video cameras) and the bed surface generally is layered with coarse gravel.</p><p>The particle is initially located at the upstream end of the test configuration, fully exposed to the uniform and fully developed turbulent channel flow. The top and side cameras are set in their suitable positions to monitor and study the behaviour of particle motion by capturing the dynamical features of sediment motion and to not interfere with flow field that pushes particle downstream.<span> </span></p><p>Using the sensor data to calculate the kinetic energy for a range of sets of sediment transport experiments with varying flow rates and particle densities, the probability distribution functions (PDFs) of particle transport features, such as particle’s total energy, are generated which give information about particle interaction with the surface bed during its motion. In addition, the effects of different flow rates, particle densities on particle energy are assessed.</p>

Particle Interaction Forces Induce Soil Particle Transport during Rainfall

2013 ◽  
Vol 77 (5) ◽  
pp. 1563-1571 ◽  
Author(s):  
Song Li ◽  
Hang Li ◽  
Chen-Yang Xu ◽  
Xue-Ru Huang ◽  
De-Ti Xie ◽  
...  
Keyword(s):  
Particle Transport ◽  
Particle Interaction ◽  
Soil Particle ◽  
Interaction Forces

Aerosol particle transport and deposition in vertical and horizontal turbulent duct flows

2000 ◽  
Vol 406 ◽  
pp. 55-80 ◽  
Author(s):  
HAIFENG ZHANG ◽  
GOODARZ AHMADI
Keyword(s):  
Aerosol Particle ◽  
Deposition Rate ◽  
Particle Transport ◽  
Particle Deposition ◽  
Flow Direction ◽  
Fluid Velocity ◽  
Deposition Velocity ◽  
Density Ratio ◽  
Shear Velocity ◽  
Brownian Diffusion

Aerosol particle transport and deposition in vertical and horizontal turbulent duct flows in the presence of different gravity directions are studied. The instantaneous fluid velocity field is generated by the direct numerical simulation of the Navier–Stokes equation via a pseudospectral method. A particle equation of motion including Stokes drag, Brownian diffusion, lift and gravitational forces is used for trajectory analysis. Ensembles of 8192 particle paths are evaluated, compiled, and statistically analysed. The results show that the wall coherent structure plays an important role in the particle deposition process. The simulated deposition velocities under various conditions are compared with the available experimental data and the sublayer model predictions. It is shown that the shear velocity, density ratio, the shear-induced lift force and the flow direction affect the particle deposition rate. The results for vertical ducts show that the particle deposition velocity varies with the direction of gravity, and the effect becomes more significant when the shear velocity is small. For horizontal ducts, the gravitational sedimentation increases the particle deposition rate on the lower wall.

The motion of solid particles suspended in viscoelastic liquids under torsional shear

1996 ◽  
Vol 324 ◽  
pp. 199-222 ◽  
Author(s):  
J. Feng ◽  
D. D. Joseph
Keyword(s):  
Flow Direction ◽  
Particle Interaction ◽  
Radial Force ◽  
Solid Particles ◽  
Small Amplitude Oscillatory Shear ◽  
Radial Migration ◽  
Local Shear ◽  
Change Of Type ◽  
Torsional Flow ◽  
And Migration

This paper presents an experimental study of the behaviour of single particles and suspensions in polymer solutions in a torsional flow. Four issues are investigated in detail: the radial migration of a shperical particle; the rotation and migration of a cylindrical particle; the particle-particle interaction and microstructures in a suspension of spheres; and the microstructures in a suspension of rods. Newtonian fluids are also tested under similar flow conditions for comparison. A spherical particle migrates outward at constant velocity unless the polymer solution is very dilute. A rod in a viscoelastic fluid has two modes of motion depending on its initial orientation, aspect ratio, the local shear rate and the magnitude of normal stresses in the fluid. In the first mode, the rod rotates along a Jeffery-like orbit around the local vorticity axis. It also migrates slowly inward. The second mode of motion has the rod aligned with the local stream at all times; the radial migration is outward. A hypothesis proposed by Highgate & Whorlow (1968) on the radial force on a particle in a cone-and-plate geometry is generalized to explain the variation of migration speed in torsional flows. Spheres form chains and aggregates when the suspension is sheared. The chains are along the flow direction and may connect to form circular rings; these rings migrate outward at a velocity much higher than that of a single sphere. Rods interact with one another and aggregate in much the same way, but to a lesser extent than spheres. It is argued that the particle interaction and aggregation are not direct results of the shear flow field. Two fundamental mechanisms discovered in sedimentation are applied to explain the formation of chains and aggregates. Finally, the competition between inertia and elasticity is discussed. A change of type is not observed in steady shear, but may happen in small-amplitude oscillatory shear.

Analytical solution for estimating the influence of a pre-existing ground water flow on a geothermal heat production-injection well system

2011 ◽  
Vol 2 (1) ◽  
pp. 13-17
Author(s):  
I. David ◽  
M. Visescu
Keyword(s):  
Ground Water ◽  
Water Flow ◽  
Geothermal Energy ◽  
Flow Direction ◽  
Energy Resource ◽  
Hot Water ◽  
Injection Well ◽  
Production Well ◽  
Ground Water Flow ◽  
The Earth

Abstract Geothermal energy source is the heat from the Earth, which ranges from the shallow ground (the upper 100 m of the Earth) to the hot water and hot rock which is a few thousand meters beneath the Earth's surface. In both cases the so-called open systems for geothermal energy resource exploitation consist of a groundwater production well to supply heat energy and an injection well to return the cooled water, from the heat pump after the thermal energy transfer, in the underground. In the paper an analytical method for a rapid estimation of the ground water flow direction effect on the coupled production well and injection well system will be proposed. The method will be illustrated with solutions and images for representative flow directions respect to the axis of the production/injection well system.

EFFECT OF GAS FLOW DIRECTION ON PASSIVE SUBSEA COOLER EFFECTIVENESS

2019 ◽  
Vol 11 (1-2) ◽  
pp. 1-16 ◽  
Author(s):  
Nikolay Ivanov ◽  
Vladimir V. Ris ◽  
Nikolay A. Tschur ◽  
Marina Zasimova
Keyword(s):  
Gas Flow ◽  
Flow Direction
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