Erosion Behaviors of Impeller Material FV520B in Centrifugal Compressor

2014 ◽  
Vol 894 ◽  
pp. 110-115 ◽  
Author(s):  
Guang Cun Wang ◽  
Jian Feng Li ◽  
Xiu Jie Jia ◽  
Zhao Ju Zhu ◽  
Qi Guo
Keyword(s):  
Centrifugal Compressor ◽  
High Speed ◽  
Erosion Rate ◽  
Impact Angle ◽  
Erosion Model ◽  
Micro Cutting ◽  
Erosion Testing ◽  
Erosion Mechanism ◽  
Compressor Impeller ◽  
The Impact

To study the erosion behaviors and mechanism of impeller material FV520B in centrifugal compressor, the erosion experiments with polygonal alumina particles were carried out on the high-speed erosion testing system. Microstructure of the erosion zone was analyzed by SEM to reveal the erosion mechanism. An erosion model to calculate the erosion rate of FV520B was developed. The results showed that, FV520B exhibited the erosion characteristics of typical plastic materials, the highest erosion rate occurred at the impact angle of 24°, the lowest erosion rate occurred at normal impact angle. The velocity index at the impact angle 24° and 90° were 3.37 and 3.68, it grew as the impact angle increased. The erosion mechanism of FV520B was micro-cutting and deformation wear, at low impact angles, the erosion was dominated by micro-cutting wear, while at high impact angle greater than 60 °, the erosion was dominated by deformation wear. Also the predictions of the erosion model were in good agreement with the results of experiments, indicating that this model can be used to estimate the erosion rate of compressor impeller under different working conditions.

Analysis of surface-erosion mechanism due to impacts of freely rotating angular particles using smoothed particle hydrodynamics erosion model

2017 ◽  
Vol 231 (12) ◽  
pp. 1537-1551 ◽  
Author(s):  
Xiangwei Dong ◽  
Zengliang Li ◽  
Qi Zhang ◽  
Wei Zeng ◽  
G.R. Liu
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Impact Angle ◽  
Surface Erosion ◽  
Free Rotation ◽  
Erosion Model ◽  
Erosion Mechanism ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
The Impact ◽  
Angular Particles

The free rotation of an angular particle during its impact on ductile surfaces is an important factor that influences the erosion mechanism. However, the phenomenon cannot be easily revealed experimentally because the incident conditions cannot be accurately controlled. In this study, a novel erosion model based on smoothed particle hydrodynamics method is proposed to simulate single and multiple impacts of particles with specified angularities on a ductile surface. The model can simulate a particle having free rotation during the impact process and initial rotation prior to the impact. The results show that the impact angle and initial orientation significantly affect the tumbling behavior, which determines the erosion mechanism. Moreover, the initial rotation is investigated by assigning an initial angular velocity to the particle at the onset of impact. The proposed smoothed particle hydrodynamics erosion model is proven to be a promising complementary method that supports experimental techniques. This study provides insight for understanding the fundamental mechanisms of surface erosion due to angular particles.

Study on the Erosion Wear Behaviors of the PMMA Plates Impacted by Air Flow Containing Sands

2013 ◽  
Vol 631-632 ◽  
pp. 366-370
Author(s):  
Ting Xie ◽  
Gang Liu ◽  
Peng Fei Wang ◽  
Yan Guo Yin
Keyword(s):  
Impact Velocity ◽  
Impact Angle ◽  
Erosion Wear ◽  
Micro Cutting ◽  
Erosion Mechanism ◽  
Erosion Mechanisms ◽  
Impact Angles ◽  
The Impact ◽  
Erosion Volume ◽  
Sand Size

The polymethymethacrylate (PMMA) plate was adopted as the test samples. The effects of impact angle, impact velocity, sand size on the erosion wear of the PMMA plates were experimentally investigated. The erosion mechanisms were also analyzed. The results showed that, the erosion volume increased nonlinearly with the increase of impact velocity, the inflection point appeared at around 13 m/s, and then the erosion volume increased rapidly. The erosion volume decreased nonlinearly as the impact angle increased. In our experiments, under the impact angle less than 60°, the smaller sand size could result in higher erosion wear. However, at 90°, the erosion volume by larger sands produced higher erosion. In fact, the erosion mechanism depends on the impact angle, at small impact angles, the main erosion mechanism is micro-cutting, and the erosion mechanism will mainly be impacting fatigue at large impact angles. At the medium impact angles, the erosion mechanism is the combination of the micro-cutting and impacting.

Research on Solid Particle Erosion Behaviors of TC4 Alloy at Different Erosion Angles

2014 ◽  
Vol 1049-1050 ◽  
pp. 167-170
Author(s):  
Bao Hui Guo
Keyword(s):  
Solid Particle ◽  
Erosion Rate ◽  
Impact Angle ◽  
Large Impact ◽  
Solid Particle Erosion ◽  
Particle Erosion ◽  
Erosion Mechanism ◽  
Tc4 Alloy ◽  
Impact Angles ◽  
The Impact

The solid particle erosion behaviors of TC4 Alloy were studied at different erosion angles. The results show that the erosion rate of TC4 alloy at impact angle 30o was higher than those at the impact angles of both 60o and 90o. At low impact angle, the erosion mechanism could be concluded as grinding erosion and furrow erosion. However, the erosion mechanism could be fatigue erosion at large impact angle.

scholarly journals A New Method for Predicting Erosion Damage of Suddenly Contracted Pipe Impacted by Particle Cluster via CFD-DEM

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1858 ◽  
Author(s):  
Jiarui Cheng ◽  
Yihua Dou ◽  
Ningsheng Zhang ◽  
Zhen Li ◽  
Zhiguo Wang
Keyword(s):  
Erosion Rate ◽  
Numerical Study ◽  
Target Surface ◽  
Impact Angle ◽  
Particle Collision ◽  
Particle Cluster ◽  
Interparticle Collision ◽  
Velocity Decay ◽  
Discrete Element Methods ◽  
The Impact

A numerical study on the erosion of particle clusters in an abrupt pipe was conducted by means of the combined computational fluid dynamics (CFD) and discrete element methods (DEM). Furthermore, a particle-wall extrusion model and a criterion for judging particle collision interference were developed to classify and calculate the erosion rate caused by different interparticle collision mechanisms in a cluster. Meanwhile, a full-scale pipe flow experiment was conducted to confirm the effect of a particle cluster on the erosion rate and to verify the calculated results. The reducing wall was made of super 13Cr stainless steel materials and the round ceramsite as an impact particle was 0.65 mm in diameter and 1850 kg/m3 in density. The results included an erosion depth, particle-wall contact parameters, and a velocity decay rate of colliding particles along the radial direction at the target surface. Subsequently, the effect of interparticle collision mechanisms on particle cluster erosion was discussed. The calculated results demonstrate that collision interference between particles during one cluster impact was more likely to appear on the surface with large particle impact angles. This collision process between the rebounded particles and the following particles not only consumed the kinetic energy but also changed the impact angle of the following particles.

Impact of Impeller Casing Treatment on the Acoustics of a Small High Speed Centrifugal Compressor

2018 ◽  
Author(s):  
Sidharath Sharma ◽  
Jorge García-Tíscar ◽  
John M. Allport ◽  
Martyn L. Jupp ◽  
Ambrose K. Nickson
Keyword(s):  
Centrifugal Compressor ◽  
High Speed ◽  
Pressure Fluctuations ◽  
Operating Conditions ◽  
Aerodynamic Noise ◽  
Noise Sources ◽  
Casing Treatment ◽  
Active Research ◽  
Ported Shroud ◽  
The Impact

Ported shroud casing treatment is widely used to delay the onset of surge and thereby enhancing the aerodynamic stability of a centrifugal compressor by recirculating the low momentum fluid in the blade passage. Performance losses associated with the use of recirculation casing treatment are well established in the literature and this is an area of active research. The other, less researched aspect of the casing treatment is its impact on the acoustics of the compressor. This work investigates the impact of ported shroud casing treatment on the acoustic characteristics of the compressor. The flow in two compressor configurations viz. with and without casing treatment operating at the design operating conditions of an iso-speed line are numerically modelled and validated with experimental data from gas stand measurements. The pressure fluctuations calculated as the flow solution are used to compute the spectral signatures at multiple locations to investigate the acoustic phenomenon associated with each configuration. Propagation of the frequency content through the ducts has been estimated with the aid of method of characteristics to enhance the content coming from the compressor. Expected tonal aerodynamic noise sources such as monopole (buzz-saw tones) and dipole (Blade Pass Frequency) are clearly identified in the acoustic spectra of the two configurations. The comparison of two configurations shows higher overall levels and tonal content in the case of a compressor with ported shroud operating at design conditions due to the presence of ‘mid-tones’.

scholarly journals Impact and Ricochet of a High Speed Projectile from a Plate

2021 ◽  
Vol 71 (6) ◽  
pp. 737-747
Author(s):  
Hussein Bassindowa ◽  
Bakhtier Farouk ◽  
Steven B. Segletes
Keyword(s):  
Titanium Alloy ◽  
High Speed ◽  
Computational Study ◽  
Incident Angle ◽  
Finite Thickness ◽  
Impact Angle ◽  
Projectile Velocity ◽  
Alloy Plate ◽  
Impact Angles ◽  
The Impact

A computational study of a projectile (either 2024 aluminum or TiAl6V4 titanium alloy) impacting a plate (either titanium alloy or aluminum) is presented in this paper. Projectile velocity (ranging from 250 m/s to 1500 m/s) with varying impact angles are considered. The presence of ricochet (if any) is identified over the ranges of the projectile velocity and impact angle considered. For the cases where ricochet is identified, the ricochet angle and velocity are predicted as functions of the incident angle and the incident velocity. The numerical results are compared with an analytical solution of the ricochet problem. The analytical solutions are from a model developed to predict the ballistic ricochet of a projectile (projectile) penetrator. The dynamics and the deformation of an aluminum (or a titanium alloy) projectile impacting on a finite thickness titanium alloy (or aluminum) plate are simulated. The current work is interesting in that it looks in the field of ballistics of different material combinations than are traditionally studied. The present simulations based on detailed material models for the aluminum and the titanium alloy and the impact physics modelling features in the LS-DYNA code provide interesting details regarding the projectile/plate deformations and post-impact projectile shape and geometry. The present results indicate that for no cases (for specified incoming velocities and impact angles considered) can an aluminum projectile penetrate a titanium alloy plate. The ricochet ‘mode predictions ‘obtained from the present simulations agree well with the ricochet ‘mode predictions’ given in an analytical model.

Numerical Investigation of a High Speed Centrifugal Compressor Impeller

2005 ◽  
Author(s):  
Shun Kang
Keyword(s):  
Secondary Flow ◽  
Flow Structure ◽  
Centrifugal Compressor ◽  
High Speed ◽  
Independent Study ◽  
Low Speed ◽  
Operation Conditions ◽  
Compressor Impeller ◽  
Secondary Flow Structure ◽  
The One

This paper presents the CFD simulations of a high speed centrifugal compressor impeller using the NUMECA Fine/Turbo software with the one equation turbulence model of Spalart-Allmaras. The simulations are validated via comparison with the experimental data. The computational grid densities are changed with the impeller tip size and a grid independent study is carried out. The flow physics of the compressor impeller is numerically studied in details, in particular, the formation of shocks and their effects on the 3D flow and the secondary flow structure are analyzed at different operation conditions, with comparison to low speed machines. It is found that the energy loss production is greatly affected by the shock waves and their interaction with the boundary layers in the inducer portion, while in the other portion, the secondary flow structure is globally the same as those in low speed machines.

Drop impingement erosion of metals

1970 ◽  
Vol 314 (1519) ◽  
pp. 549-565 ◽  
Keyword(s):  
Fatigue Failure ◽  
Solid Surface ◽  
Liquid Flow ◽  
High Speed ◽  
Erosion Rate ◽  
Impact Pressure ◽  
Specimen Surface ◽  
Microplastic Deformation ◽  
Metal Fatigue ◽  
The Impact

The object of the work has been to investigate experimentally the mechanisms of erosion in metals and alloys under drop impingement attack. For this purpose an apparatus of the wheel and jet type has been used to erode aluminium, copper, iron, cobalt and alloys of these metals. The various stages in the process from the first detectable microplastic deformation to the eventual pitting and removal of material from the surface have been investigated. In addition, experiments were carried out with the purpose of examining the effects of the normal impact pressure of a liquid on a surface in the absence of shear forces associated with liquid flow. This was achieved by propagating impact-generated compression waves through a liquid column in a filled and sealed cylinder onto a specimen surface inside the cylinder. With this arrangement the initial damage—small shallow depressions in the specimen surface— was identical with that produced under standard drop impact conditions in the wheel and jet apparatus. In either case the calculated values of the maximum impact pressure were lower than the average yield strength of each metal investigated. A complementary series of experiments was carried out in order to examine the erosive effects of liquid flow over the surface in the absence of high impact pressures. The technique used here involved a continuous high-speed water jet impinging against a solid surface at glancing incidence. This study showed that while flat well polished surfaces were apparently unaffected by the flow, lightly roughened surfaces or surfaces which contained the shallow impact depressions were severely eroded in regions adjacent to discontinuities. These various experiments suggest that the initial yielding which gives rise to the depression is associated with non-uniformity in the strength, structure and shape of the solid surface rather than with local variations in the impact pressure over the surface. The subsequent acceleration in the erosion rate is linked with the increased roughening of the surface and with an increase in the shear damage. When the surface becomes very rough and pitted, the impinging drop is deflected into less damaging streams by surface projections. This effect would account for the eventual decrease observed in the erosion rate. Further studies of the structure of the eroded surfaces have shown that the fractures have a number of features which are characteristic of metal fatigue failure. The connexion between erosion and fatigue is illustrated by similarities between the endurance curves for erosion and for the same metal in a standard fatigue test. As in the case of fatigue failure, strain energy to fracture appears to be one of the most important mechanical properties determining the erosive behaviour of a ductile metal.

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