scholarly journals Erosion Mechanism and Sensitivity Parameter Analysis of an innovative shaped Curved Pipeline

Mechanika ◽  
2020 ◽  
Vol 26 (6) ◽  
pp. 511-517
Author(s):  
Li MO ◽  
Zhiyuan WANG ◽  
Shulu FENG ◽  
Jiadai DU ◽  
Hao YI ◽  
...  
Keyword(s):  
Large Particle ◽  
Erosion Rate ◽  
Particle Diameter ◽  
Parameter Analysis ◽  
Erosion Mechanism ◽  
High Particle ◽  
Sensitivity Parameter ◽  
Particle Parameters ◽  
Harsh Conditions ◽  
Dent Depth

In the process of natural gas transportation, it is unavoidable for particles to collide with the wall, which will cause erosion of curved pipeline. Reasonable curved pipeline structure can effectively avoid the erosion failure. In this paper, an innovative shaped curved pipeline formed by extrusion of cylindrical indenter is presented. The erosion mechanism and sensitivity parameter analysis of the innovative shaped curved pipeline is studied by numerical simulation and compared with that of ordinary elbow. In addition, the effects of extrusion parameters and particle parameters on erosion of innovative shaped curved pipeline were also studied. The results show that the dent can effectively reduce the maximum erosion rate of elbow. With the increase of dent depth, the maximum erosion rate of elbow is decreasing. With the increase of indenter diameter, the ability to reduce the maximum erosion rate decreases. Under the harsh conditions of large particle diameter and high particle velocity, the dent has a better ability to reduce the maximum erosion wear rate, and the maximum erosion rate can be reduced by 26.8%.

The Pressure Drop at Critical Fluidization of Large Particles in Vibrated Fluidization Bed

2012 ◽  
Vol 550-553 ◽  
pp. 2763-2766
Author(s):  
Xue Jun Zhu ◽  
Jun Deng
Keyword(s):  
Pressure Drop ◽  
Fluidized Bed ◽  
Large Particle ◽  
Particle Diameter ◽  
Future Design ◽  
Vibration Strength ◽  
Bed Height ◽  
Large Particles ◽  
Vibrated Fluidized Bed ◽  
Critical Fluidization

The pressure drop at critical fluidization for two-dimensional vibrated fluidized bed(240 mm×80 mm) was studied, with large particle glass beads of average diameters dp of 1.8mm, 2.5mm and 3.2mm.The effect of the vibration strength, the static bed height and the particle diameter on the pressure drop was analyzed. The results of the study show that the pressure drop decreases with the increase of the vibration strength. It plays an even more prominent part with decreases of the static bed height and the particle diameter. The empirical correlation equations to predict the pressure drop was established, and the results of the prediction was compared with the experimental data, the error is in range of ±10%. The results can provide references for future design and research on the vibrated fluidized bed.

Cavitation Erosion of HVOF Coatings

1996 ◽  
Author(s):  
R. Schwetzke ◽  
H. Kreye
Keyword(s):  
Erosion Rate ◽  
Cavitation Erosion ◽  
Metallic Alloys ◽  
Erosion Mechanism ◽  
Hvof Coatings ◽  
Coating Composition ◽  
Before And After ◽  
Series Of Experiments ◽  
The Individual ◽  
Scanning Electron

Abstract The proposed paper reports a series of experiments to investigate the cavitation erosion mechanism of HVOF coatings. Vibratory cavitation erosion tests according to ASTM G 32 have been carried out with several HVOF coatings including cermets, oxides and metallic alloys. The steady state erosion rate for each coating was determined and the effect of coating composition and microstructure on the erosion rate was investigated. The morphology and microstructure of the various coatings before and after cavitation testing were analyzed by means of light optical and scanning electron microscopy in order to study the erosion mechanism. The results demonstrate that HVOF coatings of NiCrFeBSi, WC-17Co, Cr3C2-25NiCr and Cr2O3 can exhibit a rather high resistance against cavitation erosion and should be considered for application as a protective surface layer against cavitation. Furthermore, it is shown that cavitation testing can provide a useful tool to study and characterize the bond strength between individual splats as well as the brittleness of the individual phases present in the coating.

scholarly journals Numerical investigation on the solid particle erosion in elbow with water–hydrate–solid flow

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041989724 ◽  
Author(s):  
Liang Zhang ◽  
JiaWei Zhou ◽  
Bo Zhang ◽  
Wei Gong
Keyword(s):  
Reynolds Number ◽  
Flow Velocity ◽  
Erosion Rate ◽  
Particle Diameter ◽  
Stokes Number ◽  
Solid Particles ◽  
Curvature Radius ◽  
Premature Failure ◽  
Solid Flow ◽  
Erosion Zone

Erosion in pipeline caused by solid particles, which may lead to premature failure of the pipe system, is regarded as one of the most important concerns in the field of oil and gas. Therefore, the Euler–Lagrange, erosion model, and discrete phase model are applied for the purpose of simulating the erosion of water–hydrate–solid flow in submarine hydrate transportation pipeline. In this article, the flow and erosion characteristics are well verified on the basis of experiments. Moreover, analysis is conducted to have a good understanding of the effects of hydrate volume, mean curvature radius/pipe diameter ( R/ D) rate, flow velocity, and particle diameter on elbow erosion. It is finally obtained that the hydrate volume directly affects the Reynolds number through viscosity and the trend of the Reynolds number is consistent with the trend of erosion rate. Taking into account different R/ D rates, the same Stokes number reflects different dynamic transforms of the maximum erosion zone. However, the outmost wall (zone D) will be the final erosion zone when the value of the Stokes number increases to a certain degree. In addition, the erosion rate increases sharply along with the increase of flow velocity and particle diameter. The effect of flow velocity on the erosion zone can be ignored in comparison with the particle diameter. Moreover, it is observed that flow velocity is deemed as the most sensitive factor on erosion rate among these factors employed in the orthogonal experiment.

On the effect of gravitational and hydrodynamic forces on particle motion in a quiescent fluid at high particle Reynolds numbers

2008 ◽  
Vol 86 (6) ◽  
pp. 791-799
Author(s):  
M Rostami ◽  
A Ardeshir ◽  
G Ahmadi ◽  
P J Thomas
Keyword(s):  
Particle Velocity ◽  
Particle Motion ◽  
Particle Diameter ◽  
Time History ◽  
Reynolds Numbers ◽  
Added Mass ◽  
High Particle ◽  
Starting Point ◽  
History Force ◽  
The Impact

Trajectories of 5 and 10 mm metallic and plastic particles in a quiescent liquid during their sedimentation toward a plate were studied using experimental and numerical means, and the influence of gravity, drag, added mass, and history forces were evaluated. Variations of particle diameter and density allowed measurements at Reynolds numbers, based on the impact velocity, in the range of 1 000 to 13 000. A computer model was developed and the Lagrangian equation of particle motion was solved. The results showed that the combination of gravity, drag, and added mass forces are important for the simulation of the motion of small particles for the duration of their flight from the starting point to the wall impact, in the range of particle Reynolds numbers between 1000 and 5000. Comparison of the simulation results with the data showed that the predicted trajectories underestimated the experimental observations by about 1% to 4.3%. When the history force was included in the governing equation, however, excellent agreement between the measured and predicted particle trajectory was obtained. Experimental results for the motion of large particles showed oscillations in the time history of particle velocity when the particle Reynolds number was in the range of 3 000 to 13 000. Repeating the experiment, and averaging the data of a large number of experiments, yielded averaged curves for the particle velocity that did not show oscillatory values. In this case, good agreement between numerical and experimental data was observed. The study also shows that at high particle Reynolds numbers, the effect of the history force becomes negligibly small.PACS No.: 47.55kf

Particle Size Effects on Slurry Erosion of 5117 steels

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
A. Abouel-Kasem
Keyword(s):  
Aspect Ratio ◽  
Erosion Rate ◽  
Threshold Energy ◽  
Average Diameter ◽  
Silica Sand ◽  
Water Mixture ◽  
Slurry Erosion ◽  
Shape Factors ◽  
Erosion Mechanism ◽  
Erosion Rates

The effect of particles size and shape on erosion rates and erosion mechanisms of 5117 steels are investigated using slurry whirling-arm ring. Six different sized silica sand particles are used as erodent. These particles are characterized in terms of their average diameter, aspect ratio, and circularity factor. The measured average diameter varies from 112.7 μm to 516.4 μm. The wear tests are carried out at impact velocity of 15 m/s and 30 deg and 90 deg impact angles using a sand-water mixture of 1 wt % concentration. Analysis of erosion rates shows that there exists threshold energy of impacting particles at which a transition in erosion rate is noticed for sizes of 200 μm. It is also observed that the erosion rate increases with the increase in shape factors (aspect ratio and circularity factor). The surface morphology of the eroded surface at impact of 30 deg shows that below 200 μm, the erosion mechanism is indentation and material extrusion and above 200 μm, the erosion mechanism is ploughing.

Effect of Particle Parameters on Erosion Wear and Performance of Screw Centrifugal Pump

2018 ◽  
Author(s):  
Zhengjing Shen ◽  
Wuli Chu
Keyword(s):  
Centrifugal Pump ◽  
Shape Factor ◽  
Erosion Rate ◽  
Reduction Rate ◽  
Pump Efficiency ◽  
Erosion Wear ◽  
Pump Performance ◽  
Performance Reduction ◽  
Particle Parameters ◽  
And Performance

Sediment erosion is recognized as a serious engineering problem in slurry handling such as screw centrifugal pump, which has wide efficiency region and non-plugging performance. In the present study, the screw centrifugal pump was simulated based on the Euler-Lagrange method. The Mclaury model was adopted for the erosion prediction of flow passage components. By analyzing the correlation factor functions contained in the erosion model and performing some preliminary research with a simplified model, particle velocity, particle shape factor and particle concentration were selected as the influencing factors to analysis the quantitative relationship among particle parameters, erosion wear and performance of screw centrifugal pump. The results show that the erosion of volute casing is higher than impeller, and the erosion rate of suction side is higher than pressure side. The particles velocity is positively correlated with erosion wear and pump performance reduction rate. While the increase of particles shape factor shows the opposite trend. Erosion rate is found to be increases sharply and then slowly when particles concentration increases, because of the adhesion effect of sand particles in the volute casing inhibits the total erosion wear. The increase of erosion rate promoted the reduction rate of pump performance, and the pump efficiency decreased more significantly when the erosion rate increased to a certain extent. The results of this study are of great significance for further optimization of hydraulic design and structural design for screw centrifugal pump.

Chemical composition of the ATAL aerosol measured by in-situ particle mass spectrometry

2020 ◽  
Author(s):  
Oliver Appel ◽  
Andreas Hünig ◽  
Antonis Dragoneas ◽  
Sergej Molleker ◽  
Frank Drewnick ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Laser Ablation ◽  
Chemical Composition ◽  
Particle Diameter ◽  
Aerosol Layer ◽  
Aerosol Mass Spectrometer ◽  
High Particle ◽  
Aerosol Mass ◽  
Ionisation Mass Spectrometry

<p>The Asian Tropopause Aerosol Layer (ATAL) has been found to be an aerosol layer with exceptionally high particle number concentrations in the UT/LS altitude range. During the StratoClim 2017 field campaign in Nepal we deployed the novel in-situ aerosol mass spectrometer ERICA (ERC Instrument for Chemical composition of Aerosols). It combines the methods of laser ablation mass spectrometry with flash vaporization/electron impact ionisation mass spectrometry in a single instrument to analyse the chemical composition of individual aerosol particles or small particle ensembles in the particle diameter range from 100 nm to 2 µm.</p><p>The quantitative analysis shows a strong contribution of ammonium nitrate (AN) to the ATAL aerosol concentration. In this layer, the AN concentrations can be as high as 1.5 µg per standard cubic meter. We present the vertical distribution of the mass concentrations of AN as well as other contributing species like sulphate and organics.</p><p>The single particle data from the laser ablation module of ERICA show a distinct particle type with nitrate and sulphate ions without the typical components of primary aerosol (soot, dust, metals) within the ATAL, indicating that a significant fraction of the ATAL aerosol consists of secondary particles formed in the upper troposphere.</p>

Modeling Deposit Erosion in Internal Turbine Cooling Geometries

2019 ◽  
Author(s):  
Nathan D. Libertowski ◽  
Gabriel M. Geiger ◽  
Jeffrey P. Bons
Keyword(s):  
Large Particle ◽  
Erosion Rate ◽  
Flow Simulation ◽  
Road Dust ◽  
Impingement Cooling ◽  
Particle Distributions ◽  
Turbine Cooling ◽  
Key Features ◽  
Deposit Structure ◽  
Adhesive Forces

Abstract Experiments were performed to study the erosion of deposit structures due to large particle impacts (> 5 μm). Cone shaped dust deposits were created in an oversized (6.35 mm diameter) impingement cooling jet at 811 K with 0–5 μm Arizona Road Dust (ARD). Subsequently, the deposit cones were eroded with larger particle distributions (5–10, 10–20, 20–40, and 40–80 μm ARD) at various velocities and temperatures. It was found that erosion rate increased with increasing particle size and flow velocity and with decreasing temperature. The dependency on size and velocity occurs through the particle’s kinetic energy at impact, while the dependency on temperature is related to the adhesive forces in the deposit structure. Using the experimental data, an empirical erosion model was developed to be added to the OSU deposition model. A computational flow simulation combined with mesh morphing is shown to capture key features of the erosion physics.

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