Aleurite particle saltation modeling

2019 ◽  
Author(s):  
Alexey Karpov ◽  
G. I. Gorchakov ◽  
R. A. Gushchin ◽  
O. I. Datsenko
Keyword(s):  
Particle Saltation

Particle saltation removal in laser-induced plasma shockwave cleaning

2007 ◽  
Vol 254 (5) ◽  
pp. 1444-1449 ◽  
Author(s):  
Ping Zhang ◽  
Bao-Min Bian ◽  
Zhen-Hua Li
Keyword(s):  
Laser Induced Plasma ◽  
Particle Saltation

Numerical Simulation of Particle Saltation Process

2008 ◽  
Vol 26 (6) ◽  
pp. 529-550 ◽  
Author(s):  
A. Nasrollahi ◽  
S. A. A. Salehi Neyshabouri ◽  
G. Ahmadi ◽  
M. M. Namin
Keyword(s):  
Numerical Simulation ◽  
Particle Saltation

scholarly journals Measurements and numerical simulations of snow-particle saltation

1998 ◽  
Vol 26 ◽  
pp. 184-190 ◽  
Author(s):  
K. Nishimura ◽  
K. Sugiura ◽  
M. Nemoto ◽  
N. Maeno
Keyword(s):  
Friction Velocity ◽  
Laser Sheet ◽  
Impact Angle ◽  
Wind Tunnel Experiments ◽  
Mean Velocity ◽  
Measured Probability ◽  
The Mean ◽  
Snow Particle ◽  
The Relationship ◽  
Particle Saltation

First, wind-tunnel experiments were carried out to measure the trajectories of saltating snow particles with varying friction velocity. Trajectories of saltating particles were recorded by a video system with a laser sheet and trajectory statistics, such as ejection and impact velocities and angles, were obtained for each particle. Parabolic trajectories are considerably elongated with an increase in the friction velocity; impact angle was approximately the same but ejection angle decreased with increasing friction velocity. Furthermore, it should be noted that the gradient of flux decay with height decreased with friction velocity. In the experiments, a snow-particle counter, which can sense not only the number of particles but also their diameters, was introduced. The flux distribution and the transport rate obtained as a function of the particle size gave a new insight into the relationship with the friction velocity.Trajectories of saltating grains were computed, using the measurements of the initial ejection velocities, angles and the mean velocity profile of the air. The results agreed reasonably with our measurements. Using the measured probability distribution of the ejection velocities, an ensemble of trajectories was computed and thence the vertical profiles of stream-wise fluxes. The exponential decay of the flux on height was obtained in all cases and it supports the basic validity of the model, although agreement is less than expected.

scholarly journals Bed particle saltation in turbulent wall-shear flow: a review

2019 ◽  
Vol 475 (2223) ◽  
pp. 20180824 ◽  
Author(s):  
Sk Zeeshan Ali ◽  
Subhasish Dey
Keyword(s):  
Shear Flow ◽  
Mathematical Modelling ◽  
Critical Appraisal ◽  
Particle Collision ◽  
Particle Rotation ◽  
Current State ◽  
Wall Shear ◽  
Turbulent Wall ◽  
Particle Saltation

Bed particle saltation in turbulent wall-shear flow remains an intriguing phenomenon in applied hydro-dynamics. In this review, we report the current state of the art of bed particle saltation in turbulent wall-shear flow, highlighting the physical characteristics of bed particle saltation and its mathematical modelling. A critical appraisal of the mechanics of bed particle saltation is presented thorough ample experimental evidence. The salient features of bed particle saltation, encompassing the saltation height, saltation length, particle velocity, saltation duration, particle collision with the bed, particle rotation, particle resting time and particle re-entrainment, are thoroughly discussed. Both the deterministic and computational fluid dynamics approaches in modelling bed particle saltation are summarized, and the subtle role of the hydrodynamic forces is elaborated. The estimation of bedload flux in a fluvial environment, emanating from the mathematical modelling of bed particle saltation, is delineated using different modelling approaches. Finally, the challenges in modelling bed particle saltation are highlighted, and a new look at bed particle saltation is furnished.

scholarly journals Numerical model of spherical particle saltation in a channel with a transversely tilted rough bed

2009 ◽  
Vol 57 (3) ◽  
pp. 182-190 ◽  
Author(s):  
Nikolay Lukerchenko ◽  
Siarhei Piatsevich ◽  
Zdenek Chara ◽  
Pavel Vlasak
Keyword(s):  
Numerical Model ◽  
Spherical Particle ◽  
Particle Trajectory ◽  
Particle Diameter ◽  
Shear Velocity ◽  
Rough Bed ◽  
Angle Of Deviation ◽  
Bed Slope ◽  
Straight Lines ◽  
Particle Saltation

Numerical model of spherical particle saltation in a channel with a transversely tilted rough bedThis paper deals with the numerical simulation of spherical particle saltation in a channel with a rough transversely tilted bed. The numerical model presented is based on the 3D model of spherical particle saltation developed by the authors, which takes into account the translational and rotational particle motion. The stochastic method and the concept of a contact zone were used for the calculation of a particle trajectory and its dependence on the bed lateral slope, particle diameter, and shear velocity. The effect of the bed lateral slope results in a deviation of the particle trajectory from the downstream direction. Some examples of the calculation are presented. The trajectories of the saltating particles starting their movements from one point were calculated and it was shown that they are of random character and together create a bundle or fascicle of trajectories. It was found that the centrelines of the bundles can be approximated by the straight lines for low and moderate values of the bed transverse slope, i.e. slopes less than 20°. The angle of deviation of the centreline from the downstream direction increases when the bed lateral slope and/or the particle diameters increase. However, with increasing shear velocity, the deviation angle decreases. Due to the lateral bed slope the particles are sorted according to their size, and the criteria for sorting particles were defined. An example of the particle sorting was calculated and the separable and non-separable regions were determined.

scholarly journals Measurements and numerical simulations of snow-particle saltation

1998 ◽  
Vol 26 ◽  
pp. 184-190 ◽  
Author(s):  
K. Nishimura ◽  
K. Sugiura ◽  
M. Nemoto ◽  
N. Maeno
Keyword(s):  
Friction Velocity ◽  
Laser Sheet ◽  
Impact Angle ◽  
Wind Tunnel Experiments ◽  
Mean Velocity ◽  
Measured Probability ◽  
The Mean ◽  
Snow Particle ◽  
The Relationship ◽  
Particle Saltation

First, wind-tunnel experiments were carried out to measure the trajectories of saltating snow particles with varying friction velocity. Trajectories of saltating particles were recorded by a video system with a laser sheet and trajectory statistics, such as ejection and impact velocities and angles, were obtained for each particle. Parabolic trajectories are considerably elongated with an increase in the friction velocity; impact angle was approximately the same but ejection angle decreased with increasing friction velocity. Furthermore, it should be noted that the gradient of flux decay with height decreased with friction velocity. In the experiments, a snow-particle counter, which can sense not only the number of particles but also their diameters, was introduced. The flux distribution and the transport rate obtained as a function of the particle size gave a new insight into the relationship with the friction velocity.Trajectories of saltating grains were computed, using the measurements of the initial ejection velocities, angles and the mean velocity profile of the air. The results agreed reasonably with our measurements. Using the measured probability distribution of the ejection velocities, an ensemble of trajectories was computed and thence the vertical profiles of stream-wise fluxes. The exponential decay of the flux on height was obtained in all cases and it supports the basic validity of the model, although agreement is less than expected.

scholarly journals 3D Numerical Model of the Spherical Particle Saltation in a Channel with a Rough Fixed Bed

2009 ◽  
Vol 57 (2) ◽  
Author(s):  
Nikolay Lukerchenko ◽  
Siarhei Piatsevich ◽  
Zdenek Chara ◽  
Pavel Vlasak ◽  
Zdeněk Chára ◽  
...  
Keyword(s):  
Numerical Model ◽  
Spherical Particle ◽  
Fixed Bed ◽  
3D Numerical Model ◽  
Particle Saltation
Sign in / Sign up

Export Citation Format

Share Document