Turbulence Modulation Due to Solid Particles Moving with Vortex Shedding

2001 ◽  
pp. 319-324
Author(s):  
T. Kajishima ◽  
S. Takiguchi ◽  
Y. Miyake
Keyword(s):  
Vortex Shedding ◽  
Solid Particles ◽  
Turbulence Modulation

Turbulence modulation by dispersed solid particles in rotating channel flows

2002 ◽  
Vol 28 (4) ◽  
pp. 527-552 ◽  
Author(s):  
Yingkang Pan ◽  
Toshitsugu Tanaka ◽  
Yutaka Tsuji
Keyword(s):  
Solid Particles ◽  
Channel Flows ◽  
Turbulence Modulation ◽  
Rotating Channel

scholarly journals PIV test methods and mechanism on liquid turbulence modulation by solid-particles inside a centrifugal pump

2018 ◽  
Vol 63 (11) ◽  
pp. 1050-1064
Author(s):  
Baocheng Shi ◽  
Jinjia Wei ◽  
Yijie Qiu ◽  
Qiuwan Shen ◽  
Xingkai Zhang ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Test Methods ◽  
Solid Particles ◽  
Turbulence Modulation

Stochastic Large Eddy Simulation of Bluff-Body Two-Way-Coupled Gas-Particle Turbulent Flow

2011 ◽  
Author(s):  
Abdallah Sofiane Berrouk ◽  
Dominique Laurence
Keyword(s):  
Large Eddy Simulation ◽  
Bluff Body ◽  
Fluid Velocity ◽  
Solid Particles ◽  
High Mass ◽  
Steady Increase ◽  
Inertial Particles ◽  
Turbulence Modulation ◽  
Eddy Simulation ◽  
Large Eddy

With the steady increase in computing power, there have been numerous efforts to numerically quantify turbulence modulation by inertial particles. However, highly resolving the flow around thousands to millions of particles to get an accurate particle/turbulence interaction has been prohibited by the number of grid points required. Thus, physical models have been developed and “plugged” to well-resolved numerical simulations to render prediction of turbulence modulation tractable. In this work, flow turbulence modulation by dispersed solid particles in a bluff body was studied using two-way-coupled stochastic large eddy simulation. Point-force scheme was used to model the inertial particle back effects on the fluid motion. The fluid velocity field seen by inertial particles was stochastically constructed based on the filtered flow field obtained from well resolved large eddy simulations. For that purpose a Langevin-type stochastic diffusion process was used with the necessary modifications to account for particle inertia, cross-trajectory effects and the two-way coupling. The numerical results regarding mean and turbulence statistics for the fluid phase show a very good agreement with the experimental findings for both low and high mass loadings (22% and 110% respectively). This numerical investigation demonstrates also the ability of the stochastic-LES-particle approach to predict turbulence modification by inertial particles.

Modulation of turbulence by dispersed solid particles in a spatially developing flat-plate boundary layer

2016 ◽  
Vol 802 ◽  
pp. 359-394 ◽  
Author(s):  
Dong Li ◽  
Kun Luo ◽  
Jianren Fan
Keyword(s):  
Boundary Layer ◽  
Flat Plate ◽  
Fluid Velocity ◽  
Plate Boundary ◽  
Stokes Number ◽  
Point Particle ◽  
Solid Particles ◽  
Inertial Particles ◽  
Mass Loading ◽  
Turbulence Modulation

Direct numerical simulations of particle-laden spatially developing turbulent boundary layers over a flat plate have been performed to investigate the effect of inertial particles on turbulence modulation, using the Eulerian–Lagrangian point-particle approach with two-way coupling. The particles are smaller than the Kolmogorov length scale of the dilute flow, and inter-particle collisions are not considered. The simulation results show that the addition of small solid particles increases the mean streamwise fluid velocity, which in turn leads to a reduction in the boundary layer integral parameters and an increase in the skin-friction drag. These effects become more pronounced as the particle Stokes number and mass loading increase. The streamwise turbulence intensity is slightly enhanced in the close vicinity of the wall but damped in the outer layer. In contrast, the Reynolds stress and the turbulence intensities in the wall-normal and spanwise directions are substantially attenuated across the entire boundary layer, and the levels of attenuation increase monotonically with both particle Stokes number and mass loading. The exchange of kinetic energy between particles and fluid indicates that particle–fluid interactions cause extra energy dissipation, which plays a crucial role in turbulence modulation.

Experimental investigation of turbulence modulation by solid particles in a grid-generated vertical flow

2000 ◽  
Vol 21 (3) ◽  
pp. 365-373 ◽  
Author(s):  
M. Hussainov ◽  
A. Kartushinsky ◽  
Ü. Rudi ◽  
I. Shcheglov ◽  
G. Kohnen ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Solid Particles ◽  
Vertical Flow ◽  
Turbulence Modulation

Abrasive wear of polymer/steel gear drives

2008 ◽  
Vol 4 (1) ◽  
pp. 1-26
Author(s):  
Gábor Kalácska
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Material Selection ◽  
Solid Particles ◽  
Soil Types ◽  
General View ◽  
Modern Engineering ◽  
Clean Environment ◽  
Engineering Polymers ◽  
Plastic Gears

Research was performed on the friction, wear and efficiency of plastic gears made of modern engineering polymers and their composites both in a clean environment (adhesive sliding surfaces) and in an environment contaminated with solid particles and dust (abrasive), with no lubrication at all. The purpose is to give a general view about the results of abrasive wear tests including seven soil types as abrasive media. At the first stage of the research silicious sand was applied between the meshing gears and the wear of plastic and steel gears was evaluated and analyzed from the point of different material properties (elongation at break, hardness, yield stress, modulus of elasticity) and its combinations. The different correlations between the experienced wear and material features are also introduced. At the second stage of the project the abrasive sand was replaced with different physical soil types. The abrasive wear of gears is plotted in the function of soil types. The results highlight on the considerable role of physical soil types on abrasive wear resistance and the conclusions contain the detailed wear resistance. The results offer a new tribology database for the operation and maintenance of agricultural machines with the opportunity of a better material selection according to the dominant soil type. This can finally result longer lifetime and higher reliability of wearing plastic/steel parts.

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