Trajectories of saltating sand particles behind a porous fence

For the purpose of combating desertification, it is important to understand mechanisms of the wind-blown sand movement, which is essentially a complicated two-phase flow phenomenon of sand particles and air. Therefore, we investigated the flow field around a model dune and the erosion process of the dune. In this study, we employed a porous fence, which was installed on the model dune, and examined its effect on the sand movement. The erosion process and its relationship with the turbulent intensity and the flow around the dune were discussed focusing on dependence of the flow field on the fence porosity. We tested four types of porous fences, which had different porosities: 0% (no permeability), 10%, 30%, and 50%. How a position of the fence affects suppression of the dune erosion was also examined. In the present experimental range, it can be concluded that the most effective fence position to suppress the sand movement should depend on porosity of the fence.

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Chemical Classification and Particle Sizing of Foundry Sands

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118813 ◽

1985 ◽

Vol 43 ◽

pp. 388-389

Author(s):

D.S. DeMiglio

Keyword(s):

Image Analysis ◽

Energy Dispersive Spectrometer ◽

Image Analysis System ◽

Representative Sampling ◽

Foundry Sands ◽

Large Atomic Number ◽

Backscattered Electron ◽

Sand Particles ◽

Analysis System ◽

Reclamation System

Much progress has been made in recent years towards the development of closed-loop foundry sand reclamation systems. However, virtually all work to date has determined the effectiveness of these systems to remove surface clay and metal oxide scales by a qualitative inspection of a representative sampling of sand particles. In this investigation, particles from a series of foundry sands were sized and chemically classified by a Lemont image analysis system (which was interfaced with an SEM and an X-ray energy dispersive spectrometer) in order to statistically document the effectiveness of a reclamation system developed by The Pangborn Company - a subsidiary of SOHIO.The following samples were submitted: unreclaimed sand; calcined sand; calcined & mechanically scrubbed sand and unused sand. Prior to analysis, each sample was sprinkled onto a carbon mount and coated with an evaporated film of carbon. A backscattered electron photomicrograph of a field of scale-covered particles is shown in Figure 1. Due to a large atomic number difference between sand particles and the carbon mount, the backscattered electron signal was used for image analysis since it had a uniform contrast over the shape of each particle.

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Numerical simulation and optimization study of surface pressure and flow field around a triangular prism behind a porous fence

Environmental Fluid Mechanics ◽

10.1007/s10652-019-09695-9 ◽

2019 ◽

Vol 19 (4) ◽

pp. 969-987 ◽

Cited By ~ 1

Author(s):

Bingbing San ◽

Youyi Zhao ◽

Ye Qiu

Keyword(s):

Numerical Simulation ◽

Flow Field ◽

Surface Pressure ◽

Triangular Prism ◽

Simulation And Optimization ◽

Optimization Study ◽

Porous Fence

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Superhydrophobic Sands for the Preservation and Purification of Water

Coatings ◽

10.3390/coatings11020151 ◽

2021 ◽

Vol 11 (2) ◽

pp. 151

Author(s):

Yuyang Liu ◽

Chang-Hwan Choi

Keyword(s):

Water Surface ◽

Particulate Material ◽

Self Assembled Monolayer ◽

Hydrophobic Coatings ◽

Hydrophobic Coating ◽

Evaporation Loss ◽

Zno Nanocrystals ◽

Sand Particles ◽

Purification Of Water ◽

Nanoscale Roughness

Sand, a cheap and naturally abundant particulate material, was modified with photocatalytic and hydrophobic coatings to reduce evaporation loss and facilitate the purification of water. The first-level photocatalytic coatings (TiO2 or ZnO nanocrystals) rendered nanoscale roughness on the surface of the sand. The additional second-level hydrophobic coating of a self-assembled monolayer of octyltrimethoxysilane (OTS) made the sand particles superhydrophobic because of the nanoscale roughness imposed by the nanocrystals. The superhydrophobic sand particles, floating on the free surface of water due to their superhydrophobicity, significantly reduced the evaporation loss of water by 60%–90% in comparison to an uncovered water surface. When the outer hydrophobic coatings are weathered or disengaged, the inner photocatalytic coatings become exposed to water. Then, the sand particles act as photocatalysts to degrade the contaminants in water under solar radiation.

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Application of sand particles modified with NH2-MIL-101(Fe) as an efficient visible-light photocatalyst for Cr(VI) reduction

Chemosphere ◽

10.1016/j.chemosphere.2020.129365 ◽

2021 ◽

Vol 268 ◽

pp. 129365

Author(s):

Sadra Sadeghian ◽

Hossein Pourfakhar ◽

Majid Baghdadi ◽

Behnoush Aminzadeh

Keyword(s):

Visible Light ◽

Visible Light Photocatalyst ◽

Sand Particles

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

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.124332 ◽

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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COMPUTATIONAL FLUID DYNAMICS STUDY OF DUSTY AIR FLOW OVER NACA 63415 AIRFOIL FOR WIND TURBINE APPLICATIONS

Jurnal Teknologi ◽

10.11113/jt.v79.11877 ◽

2017 ◽

Vol 79 (7-3) ◽

Cited By ~ 1

Author(s):

Iham F. Zidane ◽

Khalid M. Saqr ◽

Greg Swadener ◽

Xianghong Ma ◽

Mohamed F. Shehadeh

Keyword(s):

Numerical Simulation ◽

Wind Turbine ◽

South African ◽

Stokes Equations ◽

Lift Coefficient ◽

Turbine Blades ◽

Aerodynamic Performance ◽

Accurate Estimation ◽

African Countries ◽

Sand Particles

Gulf and South African countries have enormous potential for wind energy. However, the emergence of sand storms in this region postulates performance and reliability challenges on wind turbines. This study investigates the effects of debris flow on wind turbine blade performance. In this paper, two-dimensional incompressible Navier-Stokes equations and the transition SST turbulence model are used to analyze the aerodynamic performance of NACA 63415 airfoil under clean and sandy conditions. The numerical simulation of the airfoil under clean surface condition is performed at Reynolds number 460×103, and the numerical results have a good consistency with the experimental data. The Discrete Phase Model has been used to investigate the role sand particles play in the aerodynamic performance degradation. The pressure and lift coefficients of the airfoil have been computed under different sand particles flow rates. The performance of the airfoil under different angle of attacks has been studied. Results showed that the blade lift coefficient can deteriorate by 28% in conditions relevant to the Gulf and South African countries sand storms. As a result, the numerical simulation method has been verified to be economically available for accurate estimation of the sand particles effect on the wind turbine blades.

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