Effect of impact angle, exposure time, and particle size on impact erosion

2019 ◽  
pp. 1-9
Author(s):  
Mahesh Ediriweera ◽  
Jana Chladek ◽  
Chandana Ratnayake
Keyword(s):  
Particle Size ◽  
Exposure Time ◽  
Impact Angle ◽  
Impact Erosion

scholarly journals Eco-friendly microwave-enhanced green synthesis of silver nanoparticles using Aloe vera leaf extract and their physico-chemical and antibacterial studies

2018 ◽  
Vol 7 (3) ◽  
pp. 231-240 ◽  
Author(s):  
Omid Ahmadi ◽  
Hoda Jafarizadeh-Malmiri ◽  
Naeimeh Jodeiri
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Exposure Time ◽  
Leaf Extract ◽  
Aloe Vera ◽  
Synthesis Conditions ◽  
Stabilizing Agents ◽  
Microwave Exposure ◽  
Mean Particle Size ◽  
Vis Spectroscopy

Abstract Silver nanoparticles (AgNPs) were synthesized using Aloe vera leaf extract as both reducing and stabilizing agents via microwave irradiation method. The effects of the microwave exposure time and the amount of AgNO3 solution on the mean particle size and concentration of the synthesized AgNPs solution were investigated using response surface methodology. The synthesized AgNPs were characterized by transmission electron microscopy, UV-Vis spectroscopy, and dynamic light scattering. Well-dispersed and spherically fabricated AgNPs with mean particle size (46 nm) and maximum concentration (64 ppm) and zeta potential (+15.5 mV), were obtained at optimal synthesis conditions, using 9 ml of AgNO3 (1 mm) and 0.1 ml of Aloe vera extract during microwave exposure time of 360 s. The antibacterial activity of the synthesized AgNPs was tested using Escherichia coli and Staphylococcus aureus bacteria and the obtained results indicated their significant inhibitory effects against these two Gram-negative and Gram-positive bacteria.

Study on Process of Particle Impact on Curved Surface of Vane by Finite Element Method

2010 ◽  
Vol 139-141 ◽  
pp. 1303-1307
Author(s):  
Xiao Jing Yang ◽  
Yi Lin Chi ◽  
Guan Zhang He
Keyword(s):  
Particle Size ◽  
Energy Exchange ◽  
Surface Deformation ◽  
Plastic Property ◽  
Impact Angle ◽  
Surface Shape ◽  
Curved Surface ◽  
Particle Impact ◽  
Size Of Particles ◽  
Distribution Of Stress

The process of particle impacting and contacting curved surface of vane was studied, and the characteristics of particle size, particle initial velocity and its impacting direction affect the stress of subsurface were analyzed by using ANSYS/LS-DANY software. It is shown that the interaction between particles and surface of vane is affected by nonlinear factors such as the elastic-plastic property of material, the state of impacting and contacting and surface shape. The increment in particle size increases the stress of the surface impacted and the sphere of action is also enlarged. The influence of the size of particles is remarkable. Particle impact velocity is related to energy exchange and has influences on stress value and the area of surface deformation. Due to impact angle is related to shape of curved vane, so the distribution of stress is changed and the value of the stress in surface layer is also influenced when particles impact curved surface of vane from different directions. The research will be helpful to disclose the mechanics of the wear on the condition of particle impact.

Influence of the partial substitution of fine aggregate by granite powder in mortar on the process of natural carbonation

2019 ◽  
Vol 38 (3) ◽  
pp. 254-262 ◽  
Author(s):  
Júlio Lopes da Silva ◽  
Daniel Baracuy da Cunha Campos ◽  
Alberto Casado Lordsleem ◽  
Yeda Vieira Povoas
Keyword(s):  
Particle Size ◽  
Exposure Time ◽  
Time Variable ◽  
Partial Substitution ◽  
Fine Aggregate ◽  
Carbonation Depth ◽  
Experimental Planning ◽  
Carbonation Process ◽  
Granite Powder ◽  
Natural Carbonation

This article presents an evaluation of the influence on the natural carbonation process of the use of granite cutting residue as a replacement for fine aggregate in mortars. The methodology adopted consisted of replacing the fine aggregate with granite cutting residue, analysing the carbonation depth with the aid of an experimental planning matrix of 23 + 3 repetitions at the central point. The influence of the exposure time, the percentage of residue in the mixture, and the particle size of the residue used were evaluated. The exposure time variable was found to have the greatest influence on the carbonation process. Under the conditions analysed, granite residue was found to be beneficial, reducing the carbonation depth.

Experimental Investigation on the Influence of Particle Size in a Submerged Slurry Jet on Erosion Rates and Patterns

2017 ◽  
Author(s):  
Soroor Karimi ◽  
Amir Mansouri ◽  
Siamack A. Shirazi ◽  
Brenton S. McLaury
Keyword(s):  
Particle Size ◽  
Erosion Rate ◽  
Erosive Wear ◽  
Impact Angle ◽  
Piping System ◽  
Slurry Erosion ◽  
Material Particle ◽  
Impact Speed ◽  
Effect Of Particle Size ◽  
Sand Particles

Sand particles entrained in fluids can cause erosive wear and damage to piping materials by impacting their surfaces which could result in failure of the piping system. Several parameters have been determined to affect the erosion behavior and mechanism of solid particle erosion. Some of these parameters include surface material, particle impact speed and angle, and particle size, shape and hardness. However, the effect of particle size on the total erosion rate and local erosion pattern has not been thoroughly investigated. It has been observed that sand particles with various sizes cause different slurry erosion patterns. Changing the particle size alters the Stokes number and consequently produces different erosion patterns and magnitudes. Thus, the effects of particle size on total erosion rate and erosion pattern in a submerged slurry jet are investigated for different impingement angles. Experiments are performed on 316 stainless steel specimens for average particles sizes of 25, 75, 150, and 300 μm. The jet angle is varied to 45, 75 and 90 degrees, and the slurry jet velocity is set to 14 m/s. The erosion pattern of the specimen is examined by obtaining the 3D microscopic profile of the eroded specimen by means of an optical profiler. It is found that the erosion profile changes as the jet angle varies. It is also observed that erosion profile is significantly different for smaller particles as compared to the larger particles. Moreover, these differences become more pronounced as the jet angle decreases. The present work discusses the differences of erosion patterns produced by both large and small particles. Computational Fluid Dynamics (CFD) is also used to study the effect of particle size on particle trajectories, impact speed, and impact angle. Also, CFD results help in explaining the differences observed in the erosion profiles caused by different particle sizes.

Revealing instability and irreversibility in nonaqueous sodium–O2 battery chemistry

2016 ◽  
Vol 52 (62) ◽  
pp. 9691-9694 ◽  
Author(s):  
Sayed Youssef Sayed ◽  
Koffi P. C. Yao ◽  
David G. Kwabi ◽  
Thomas P. Batcho ◽  
Chibueze V. Amanchukwu ◽  
...  
Keyword(s):  
Particle Size ◽  
Exposure Time

Charging kinetics and reversibility of Na–O2 batteries can be influenced greatly by the particle size of NaO2 formed upon discharge, and exposure time (reactivity) of NaO2 to the electrolyte.

Importance of Accounting for Finite Particle Size in CFD-Based Erosion Prediction

2018 ◽  
Author(s):  
Gianandrea Vittorio Messa ◽  
Yongbo Wang
Keyword(s):  
Particle Size ◽  
Prediction Models ◽  
Jet Impingement ◽  
Point Particle ◽  
Solid Particles ◽  
Future Research ◽  
Theoretical Point ◽  
Slurry Flow ◽  
Erosion Prediction ◽  
Impact Erosion

Being capable in predicting the removal of material from a surface subjected to the impingements of solid particles within a carrier liquid is of considerable industrial interest. This phenomenon, called impact erosion, is of concern in many applications due to its severe technical and economic consequences. The use of Computational Fluid Dynamics (CFD) techniques for impact erosion prediction is a challenging approach to avoid the cost and complexity of laboratory testing. A well-established methodology exists for CFD-based erosion estimation, consisting in the simulation of the slurry flow by an Eulerian–Lagrangian two-phase model followed by the application of an empirical erosion correlation to estimate the loss of material produced by each particle-wall impact. One of the main assumptions of this approach is that the solids are treated as massive point particles, even if, from a theoretical point of view, this approximation may be too simplistic, as it requires the particle size to be infinitesimal. The objective of the present study was, primarily, to assess how the point–particle treatment of the dispersed phase may affect the accuracy of CFD-based erosion prediction models. Based on these findings, numerical strategies were proposed in order to correct for the induced error without the need of resorting to a fully-resolved description of the slurry flow, which would not be affordable in practical applications due to its excessive computational burden. As a first step, reference was made to the benchmark case of slurry abrasive jet impingement test. The obtained results will open the way for addressing more complex flows in future research.

scholarly journals Studies on structural, mechanical and erosive wear properties of ZA-27 alloy-based micro-nanocomposites

2021 ◽  
pp. 146442072199487
Author(s):  
Aleksandar Vencl ◽  
Mara Kandeva ◽  
Elena Zadorozhnaya ◽  
Petr Svoboda ◽  
Michal Michalec ◽  
...  
Keyword(s):  
Particle Size ◽  
Wear Resistance ◽  
Erosive Wear ◽  
Impact Angle ◽  
Wear Testing ◽  
Zinc Alloy ◽  
Wear Properties ◽  
Metal Matrix Nanocomposites ◽  
New Class ◽  
Alloy Base

Metal matrix nanocomposites represent a relatively new class of material, which is still being extensively investigated. Most of the studies, however, are devoted to aluminium- or magnesium-based nanocomposites. A limited number of studies focus on zinc alloy base nanocomposites, with fewer still concentrating on zinc alloy base micro-nanocomposites. In addition, most of the tribological studies investigate adhesive or abrasive wear resistance, whereas studies of erosive wear resistance lag well behind. It was previously shown that the presence of nanoparticles in ZA-27 alloy-based nanocomposites led to a slight increase in erosive wear resistance. Upon discovering that, the aim became to produce micro-nanocomposites that would retain the positive effect of nanoparticles, while further elevating performance, by combining microparticles with nanoparticles. The ZA-27 alloy-based micro-nanocomposites were reinforced with 3 wt. % Al2O3 microparticles (particle size approx. 36 μm) and with four different amounts (0.3, 0.5, 0.7 and 1 wt. %) of Al2O3 nanoparticles (particle size 20–30 nm). Tested materials were produced by the compocasting process, with mechanical alloying pre-processing. Solid particle erosive wear testing, with particle impact angle of 90°, showed that all micro-nanocomposites had significantly increased wear resistance in comparison to the reference material.

Study on Rebound Characteristics of Fine Spherical Particles Impacting an AISI 403 Steel With High Velocity

2015 ◽  
Author(s):  
Juan Di ◽  
Shun-sen Wang ◽  
Liu-xi Cai ◽  
Shang-fang Cheng ◽  
Chuang Wu
Keyword(s):  
Particle Size ◽  
High Velocity ◽  
Particle Diameter ◽  
Impact Angle ◽  
Spherical Particles ◽  
Dissipated Energy ◽  
Normal Velocity ◽  
Relative Impact ◽  
Restitution Coefficient ◽  
The Impact

Impingement on blade surface by fine particles with high velocity is commonly seen in steam turbines, gas turbines and compressors, which affect the service life and reliability of the equipment. Study on particles’ rebound characteristics is of great significance to reduce the blade erosion and to control particle trajectory. Based on the nonlinear explicit dynamics analysis software ANSYS/LS-DYNA, the impacts of fine spherical particles with different diameters (20 to 500μm) on a typical martensitic stainless steel (AISI 403) target with high velocity (50 to 250m/s) have been systematically studied. The influences of incident velocities, impact angles, particles sizes on its rebound characteristics, relative impact depth, and relative dissipated energy have been analyzed. Results show that velocity restitution coefficient e decreased with the impact angle β1, the incident velocity V1, and the particle size dp. However, the role of particle size on the velocity restitution coefficient seemed to be far less than that of the other two factors. Both of particle’s tangential and normal velocity coefficient of restitution declined with the increasing impact angle in most cases. However, when the incident velocity V1 = 200m / s and the impact angle β1 > 45°, the tangential velocity restitution coefficient et of 100 μm and 200 μm particles increased with the increase in the impact angle β1. The reason might be that the relative impact depth drel was located a zone ranged from 0.1515 to 0.1677, where the tangential rebound behavior could be enhanced. Most of the variation of the tangential and normal velocity restitution coefficient along β1 decreased with the increase in the particle diameter. However, when V1 = 200m/s and β1 > 15°, the tangential reflected velocity of the larger particles was enhanced gradually. In addition, the values of the relative impact depth drel increased with the increasing impact angle and incident velocity, and it increased with the increasing particle diameter in most cases. The relative dissipated energy of particles steadily increased with the impact angle and incident velocity, respectively. Particle diameter had little effect on energy dissipation in comparison with the impact angle and incident velocity.

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