Simulation of Homogeneous Particle Size in Fluid Flow by Using DPM-DEM

2019 ◽  
pp. 549-555
Author(s):  
Nurhanani A. Aziz ◽  
M. H. Zawawi ◽  
N. M. Zahari ◽  
Aizat Abas ◽  
Aqil Azman
Keyword(s):  
Particle Size ◽  
Fluid Flow ◽  
Homogeneous Particle

scholarly journals A sample formation procedure to obtain homogeneous post-erosion particle size distribution

2019 ◽  
Vol 92 ◽  
pp. 02015
Author(s):  
Shijin Li ◽  
Adrian R. Russell
Keyword(s):  
Particle Size ◽  
Fine Particles ◽  
Internal Erosion ◽  
Triaxial Tests ◽  
Experimental Investigations ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
The Matrix ◽  
Homogeneous Particle ◽  
Coarse Soil

Internal erosion (suffusion) is caused by water seeping through the matrix of coarse soil and progressively transporting out fine particles. The mechanical strength of soils within water retaining structures may be affected after internal erosion occurs. However, most experimental investigations on the mechanical consequences of internal erosion have used triaxial tests on samples having nonhomogeneous particle size distributions along their lengths. Such nonhomogeneities arise from the most commonly used sample formation procedure, in which seeping water enters one end of a sample and washes fine particles out the other. In this paper a new soil sample formation procedure is presented which results in homogeneous particle size distributions along the direction of seepage, that is at all locations along a sample's length.

Influence of particle-size distribution homogeneity on shearing of soils subjected to internal erosion

2020 ◽  
Vol 57 (11) ◽  
pp. 1684-1694
Author(s):  
Shijin Li ◽  
Adrian R. Russell ◽  
David Muir Wood
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Soil Sample ◽  
Size Distribution ◽  
Fine Particles ◽  
Internal Erosion ◽  
Triaxial Tests ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Homogeneous Particle

Internal erosion (suffusion) is caused by water seeping through the matrix of coarse soil and progressively transporting out fine particles. The mechanical strength and stress–strain behavior of soils within water-retaining structures may be affected by internal erosion. Some researchers have set out to conduct triaxial erosion tests to study the mechanical consequences of erosion. Prior to conducting a triaxial test they subject a soil sample, which has an initially homogeneous particle-size distribution and density throughout, to erosion by causing water to enter one end of a sample and wash fine particles out the other. The erosion and movement of particles causes heterogeneous particle-size distributions to develop along the sample length. In this paper, a new soil sample formation procedure is presented that results in homogeneous particle-size distributions along the length of an eroded sample. Triaxial tests are conducted on homogeneous samples formed using the new procedure as well as heterogeneous samples created by the more commonly used approach. Results show that samples with homogeneous post-erosion particle-size distributions exhibit slightly higher peak deviator stresses than those that were heterogeneous. The results highlight the importance of ensuring homogeneity of post-erosion particle-size distributions when assessing the mechanical consequences of erosion. Forming samples using the new procedure enables the sample’s response to triaxial loading to be interpreted against a measure of its initially homogenous state.

On the Possible Mechanisms of Porosity Formation during Laser Melt Injection (LMI) Technology

2008 ◽  
Vol 589 ◽  
pp. 79-84 ◽  
Author(s):  
Gábor Buza ◽  
Viktória Janó ◽  
Mária Svéda ◽  
Olga Verezub ◽  
Zoltán Kálazi ◽  
...  
Keyword(s):  
Particle Size ◽  
Fluid Flow ◽  
Laser Power ◽  
Flow Analysis ◽  
Bath Temperature ◽  
Shielding Gas ◽  
Gas Velocity ◽  
Porosity Formation ◽  
Beam Velocity ◽  
Fluid Flow Analysis

In the present study the analysis of 5 different mechanisms of porosity formation during laser melt injection (LMI) technology were performed. Experiments were supported by thermodynamic and fluid-flow analysis. Special attention should be paid to i. clean the surface of the substrate, ii. use inert shielding gas, iii. use proper particle size and gas velocity, iv. use proper laser power and laser beam velocity to control bath temperature and v. deoxidize the surface of the added particles.

EFFECTS OF COLD EXPOSURE AND PLANT SPECIES ON FORAGE INTAKE, CHEWING BEHAVIOR AND DIGESTA PARTICLE SIZE IN SHEEP

1985 ◽  
Vol 65 (1) ◽  
pp. 69-76 ◽  
Author(s):  
K. CHAI ◽  
L. P. MILLIGAN ◽  
P. M. KENNEDY ◽  
G. W. MATHISON
Keyword(s):  
Particle Size ◽  
Fluid Flow ◽  
Cold Stress ◽  
Rumen Fluid ◽  
Red Clover ◽  
Fluid Retention ◽  
Feed Consumption ◽  
Reed Canarygrass ◽  
Forage Intake ◽  
Voluntary Intake

Three closely shorn sheep were allotted to each of three diets of chopped hay prepared from red clover, reed canarygrass and bromegrass, respectively. The animals were housed at 25, 10 and −5 °C during three periods of 28 days. For the final 8 days of each period, each individual sheep was restricted to 90% of its voluntary feed consumption and hay was given at intervals of 2 h. Eating and chewing behavior, rumen fluid kinetics and digesta particle size were determined. Voluntary intake of clover hay was greater, but chews during eating and rumination were less than for sheep consuming grass hay. The small particle fractions present in the duodenum and rumination activity were greater in the sheep fed grasses. Feed intake, rumination chews and duration, and digesta particle size in the duodenum were increased in sheep housed at −5 °C. Eating duration and chews, particle size of rumen digesta and rumen fluid volume were not affected by cold stress, but fluid retention time was reduced, while daily fluid flow from the rumen tended to increase. Key words: Forage intake, cold stress, chewing behavior, digesta particle size, fluid passage

Effect Analysis of Various Gradient Particle Size Distribution on Electrical Performance of Anode-Supported SOFCs With Gradient Anode

2019 ◽  
Author(s):  
Pei Fu ◽  
Yuansheng Song ◽  
Jian Yang ◽  
Qiuwang Wang
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Molar Fraction ◽  
Particle Diameter ◽  
Electrical Performance ◽  
Diameter Distribution ◽  
Effect Analysis ◽  
Anode Microstructure ◽  
Homogeneous Particle

Abstract Gradient particle size anode has shown great potential in improving the electrical performance of anode-supported solid oxide fuel cells (SOFCs). In the present study, a 3-D comprehensive model is established to study the effect of various gradient particle size distribution on the cell electrical performance for the anode microstructure optimization. The effect of homogeneous particle size on the cell performance is studied first. The maximum current density of homogeneous anode SOFC is obtained for the comparison with the electrical performance of gradient anode SOFC. Then the effect of various gradient particle size distribution on the cell molar fraction and polarization losses distribution is analyzed and discussed in detail. Increasing the particle diameter gradient can effectively reduce the anodic concentration overpotential. Decreasing the particle diameter of AFL2 is beneficial to reducing the activation and ohmic overpotentials. On these bases, the comprehensive electrical performances of SOFCs with gradient particle size anode and homogeneous anode are compared to highlight the optimal gradient particle diameter distribution. In the studied cases of the present work, the gradient particle diameter of 0.7 μm, 0.4 μm and 0.1 μm at ASL, AFL1 and AFL2 (Case 3) is the optimal particle size distribution.

Study on Preparation of LiNi0.5Co0.2Mn0.3O2 Precursor-Spherical Ni0.5Co0.2Mn0.3O2(OH)2

2015 ◽  
Vol 816 ◽  
pp. 676-681 ◽  
Author(s):  
Xiao Long Qu ◽  
Zheng Fu Zhang ◽  
Jin Cheng ◽  
Xiao Yan Wang
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tap Density ◽  
Homogeneous Particle ◽  
Co Precipitation ◽  
Scanning Electron

The spherical Ni0.5Co0.2Mn0.3(OH)2 powders were prepared by ammonia-hydroxide co-precipitation method. The influence of different synthesizing factors on the precursors characteristic were investigated. The product prepared with optimized condition has tap density of D≥1.7g·cm-3, and middle particle size D50≈3.6μm. The X-ray diffraction (XRD) results showed that the precursor can be indexed by a hexagonal β-Ni (OH)2 structure. The scanning electron microscope (SEM) results showed that the powders had quasi-spherical pattern and homogeneous particle size distribution.

scholarly journals Influence of Iron on the Size and Distribution of Metallic Lanthanum Particles in Free-Machining Titanium Alloys Ti 6Al 7Nb xFe 0.9La

2013 ◽  
Vol 765 ◽  
pp. 42-46 ◽  
Author(s):  
Florian Brunke ◽  
Eike Meyer-Kornblum ◽  
Carsten Siemers
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Rare Earth ◽  
Elevated Temperature ◽  
Titanium Alloys ◽  
Room Temperature ◽  
Particle Distribution ◽  
Earth Metal ◽  
Homogeneous Particle ◽  
Micrometer Size

The addition of the rare earth metal Lanthanum to (α+β)-Titanium alloys like Ti 6Al 4V or Ti 6Al 7Nb improves their machinability as short chips form during machining. In related alloys, metallic Lanthanum is distributed as micrometer-size particles which are mainly located at the grain boundaries. In case Iron is present in Lanthanum containing (α+β)-Titanium alloys, a more homogeneous particle distribution is observed leading to improved ductility at room temperature and elevated temperature compared to Iron-free alloys. In the present study, the influence of Iron on the Lanthanum particle size and distribution was investigated in the system Ti 6Al 7Nb xFe 0.9La. First, the solidification behaviour was simulated. Afterwards, alloys with different amounts of Iron (0.25 %, 0.5 % and 1.0 %) were produced. The microstructure of these alloys as well as their deformability and mechanical properties at room temperature were analyzed which were improved compared to the Iron-free Ti 6Al 7Nb 0.9La and Ti 6Al 4V 0.9La alloys.

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