scholarly journals Theoretical Prediction Method for Erosion Damage of Horizontal Pipe by Suspended Particles in Liquid–Solid Flows

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4099
Author(s):  
Guoqiang Liu ◽  
Wenzhe Zhang ◽  
Liang Zhang ◽  
Jiarui Cheng
Keyword(s):  
Small Angle ◽  
Pipe Wall ◽  
Low Cycle Fatigue ◽  
Prediction Method ◽  
Impact Angle ◽  
Wall Material ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Erosion Damage ◽  
The Impact

In order to study the erosion of a pipe wall via a liquid–solid suspension flow, a two-phase flow model combined with an erosion forecasting model for multiparticle impact on horizontal pipe wall surfaces was established in this work on the basis of low-cycle fatigue theory. In the model establishment process, the effects of particle motion and material damage were considered, and a simplified method for predicting horizontal wall erosion was obtained. The calculated results showed that the particles impact the wall at a small angle of most liquid flow velocities, causing cutting erosion damage of the wall. The settling velocity and fluctuating velocity of the particles together determine the radial velocity of the particles, which affects the impact angle of the particles. The cutting erosion caused by the small-angle impact of the particles in the pipe is more likely to cause rapid loss of the wall material. Therefore, the pipe wall is usually evenly thinned.

scholarly journals Two-Phase Optimal Guidance Law considering Impact Angle Constraint with Bearings-Only Measurements

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Tianning Wang ◽  
Shengjing Tang ◽  
Jie Guo ◽  
Haoqiang Zhang
Keyword(s):  
Sliding Mode ◽  
Information Matrix ◽  
Impact Angle ◽  
Estimation Accuracy ◽  
Two Phase ◽  
Terminal Sliding Mode ◽  
Guidance Law ◽  
Optimal Guidance ◽  
The Impact ◽  
Impact Angle Constraint

The implementation of advanced guidance laws with bearings-only measurements requires estimation of the range information. To improve estimation accuracy and satisfy the impact angle constraint, this paper proposes a two-phase optimal guidance law consisting of an observing phase and an attacking phase. In the observing phase, the determinant of Fisher information matrix is maximized to achieve the optimal observability and a suboptimal solution expressed by leading angle is derived analytically. Then, a terminal sliding-mode guidance law is designed to track the desired leading angle. In the followed attacking phase, an optimal guidance law is integrated with a switching term to satisfy both the impact angle constraint and the field-of-view constraint. Finally, comparison studies of the proposed guidance law and a traditional optimal guidance law are conducted on stationary targets and maneuvering targets cases. Simulation results demonstrate that the proposed guidance law is able to improve the range observability and achieve better terminal performances including impact angle accuracy and miss distance.

The Impact of Surface Tension on the Oil-Water Stratified Flow

2011 ◽  
Vol 383-390 ◽  
pp. 826-829 ◽  
Author(s):  
Dao Zhen Xu ◽  
Guo Zhong Zhang ◽  
Xin Zhang
Keyword(s):  
Surface Tension ◽  
Two Phase Flow ◽  
Large Diameter ◽  
Phase Flow ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Diameter Pipe ◽  
Small Density ◽  
Oil Water ◽  
The Impact

The stratified water-oil two—phase flow was modeled using VOF method in horizontal pipe and surface tension was taken into consideration using CSF model. It was found that the surface tension had great impact on the small density difference two-phase flow even in large diameter pipe, which would lead the interface curved and pressure gradient increased.

The impact angle dependence of erosion damage caused by solid particle impact

Wear ◽  
1997 ◽  
Vol 203-204 ◽  
pp. 573-579 ◽  
Author(s):  
Y.I. Oka ◽  
H. Ohnogi ◽  
T. Hosokawa ◽  
M. Matsumura
Keyword(s):  
Solid Particle ◽  
Impact Angle ◽  
Particle Impact ◽  
Erosion Damage ◽  
Angle Dependence ◽  
The Impact

Analysis on Torsional Fatigue Life of Turbo-Generator Shafts

2011 ◽  
Vol 467-469 ◽  
pp. 1858-1863 ◽  
Author(s):  
Yu Jiong Gu ◽  
Tie Zheng Jin
Keyword(s):  
Fatigue Life ◽  
High Cycle Fatigue ◽  
Low Cycle Fatigue ◽  
Circuit Simulation ◽  
Short Circuit ◽  
Cycle Fatigue ◽  
Two Phase ◽  
Torsional Fatigue ◽  
Turbo Generator ◽  
The Impact

Both low-cycle fatigue and high-cycle fatigue exist during torsional vibrations, but the impact of high-cycle fatigue has rarely been considered. In this paper, a torsional fatigue life analyzing method used for torsional vibration of turbo-generator shafts has been developed based on Manson-Coffin equation and high-cycle fatigue theory. The method has been used to estimate the torsional fatigue life in the most dangerous section of the shafts in a power plant. The cumulative torsional fatigue damage under two-phase short circuit simulation has been predicted.

Wavelet Analysis of Sound Signal in Fluid-Filled Viscoelastic Pipes

2002 ◽  
Author(s):  
Matjaz Prek
Keyword(s):  
Wavelet Transform ◽  
Material Properties ◽  
Sound Speed ◽  
Pipe Wall ◽  
Sound Signal ◽  
Wall Material ◽  
Flexural Waves ◽  
Frequency Dependent ◽  
Time Frequency ◽  
The Impact

In viscoelastic pipes, where the material properties depends on a complex bulk modulus as well as on a complex shear modulus, the sound field within the fluid is affected. Therefore, the dispersion of flexural waves occurs in the pipe, while the speed of flexural waves decreases due to the coupled fluid mass. Coupling between the pipe wall and the fluid also decreases the sound speed in the fluid. Likewise, the speed of sound in fluid is frequency-dependent, just as the group velocity of bending waves depends on the frequency. Wavelet transform of non-stationary sound signal was used to identify the frequency-dependent fluid sound speed. A time-frequency map, constructed by plotting the wavelet coefficient against the translation and scale parameters, shows an alteration in the low frequency waves. The so called fluid mode and pipe mode resonant frequencies are also clearly evident. Lastly, the impact of different pipe wall material properties is also shown. Results suggests that the wavelet transform gives in general more information from measured results.

scholarly journals Characterization of the Solid Particle Erosion of the Sealing Surface Materials of a Ball Valve

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 263
Author(s):  
Donghua Peng ◽  
Shaohua Dong ◽  
Zhiqiang Wang ◽  
Dongying Wang ◽  
Yinuo Chen ◽  
...  
Keyword(s):  
Erosion Rate ◽  
Cfd Simulation ◽  
Two Phase Flow ◽  
Simulation Analysis ◽  
Impact Angle ◽  
Ball Valve ◽  
Phase Flow ◽  
Two Phase ◽  
Valve Sealing ◽  
The Impact

The ball valve is an essential piece of equipment in an oil and gas pipeline. The sand particles transported through the pipeline can cause erosion and wear to the ball valve, thus causing it to fail, leading to serious safety hazards. In this paper, the self-designed erosion experiment method was combined with computational fluid dynamics (CFD), while the Euler-Lagrange method was also introduced to optimize the Oka erosion model and Ford particle-wall rebound model. The erosion mechanism and characteristics of the ball valve sealing surface in gas-solid two-phase flow were simulated, while the erosion condition of the specimen was analyzed and compared when exposed to different factors, such as different particle velocities, impact angle, particle size, and specimen materials. The experimental data conformed well to the CFD erosion simulation data, verifying the accuracy of the CFD simulation analysis. The results indicated that the worn surface was caused by various wear mechanisms, while a “stagnation zone” was identified at the center of the specimen. The maximum erosion area, which was U-shaped, was also located at the center. The erosion rate increased in conjunction with an increase in the particle velocity and size, both of which failed to affect the erosion pattern. The erosion rate initially increased, after which it decreased with the impact angle, reaching the maximum value at an impact angle of 30°. This paper summarizes the erosion failure mechanism and characteristics in gas–solid two-phase flow and provides both technical support and a theoretical basis for the on-site maintenance of essential vulnerable parts in the pipeline, such as ball valves.

Development of Prediction Technology of Two-Phase Flow Dynamics Under Earthquake Acceleration — (4) Measurement of Bubble Deformation Near Wall Under Flow Rate Fluctuation

2012 ◽  
Author(s):  
Satoshi Okachi ◽  
Masaki Seto ◽  
Hideaki Monji ◽  
Akiko Kaneko ◽  
Yutaka Abe ◽  
...  
Keyword(s):  
Flow Rate ◽  
Two Phase Flow ◽  
Pipe Wall ◽  
Flow Behavior ◽  
Plug Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Bubble Deformation ◽  
Rate Fluctuation

In order to clear the two-phase flow behavior under earthquake, a systematic study is done experimentally and numerically. The present study is one on the series of the study on two-phase flow under earthquake, and focuses on the flow rate fluctuation. The flow rate fluctuation was added to bubbly or plug flow in a horizontal pipe, and flow behavior was measured by PIV and image processing. The bubble deformation near the pipe wall was observed and the velocity field around the bubble was shown. The bubble coalescence was also observed under the flow rate fluctuation condition.

Cryogenic Chilldown Model for Stratified Flow Inside a Pipe

2005 ◽  
Author(s):  
Jun Liao ◽  
Kun Yuan ◽  
Renwei Mei ◽  
James F. Klausner ◽  
Jacob Chung
Keyword(s):  
Heat Transfer ◽  
Wall Temperature ◽  
Boiling Heat Transfer ◽  
Pipe Wall ◽  
Computational Cost ◽  
Stratified Flow ◽  
Nucleate Boiling ◽  
Transfer Model ◽  
Two Phase ◽  
Horizontal Pipe

A pseudo-steady model has been developed to predict the chilldown history of the pipe wall temperature in horizontal transport pipelines for cryogenic fluids. A new film boiling heat transfer model is developed by incorporating the stratified flow structure for cryogenic chilldown. A modified nucleate boiling heat transfer correlation for the cryogenic chilldown process inside a horizontal pipe is proposed. The efficacy of the correlations is assessed by comparing the model predictions with measured values of wall temperature in several azimuthal positions in a well controlled experiment by Chung et al. (2004). The computed pipe wall temperature histories match well with the measured results. The present model captures important features of thermal interaction between the pipe wall and the cryogenic fluid, provides a simple and robust platform for predicting the pipe wall chilldown history in a long horizontal pipe at relatively low computational cost, and builds a foundation to incorporate the two-phase hydrodynamic interaction in the chilldown process.

Wavelet Transform of Sound Signal in Fluid-Filled Viscoelastic Pipes

2001 ◽  
Author(s):  
Matjaz Prek
Keyword(s):  
Wavelet Transform ◽  
Material Properties ◽  
Sound Speed ◽  
Pipe Wall ◽  
Sound Signal ◽  
Wall Material ◽  
Flexural Waves ◽  
Frequency Dependent ◽  
Time Frequency ◽  
The Impact

Abstract In viscoelastic pipes, where the material properties depends on a complex bulk modulus as well as on a complex shear modulus, the sound field within the fluid is affected. Therefore, the dispersion of flexural waves occurs in the pipe, while the speed of flexural waves decreases due to the coupled fluid mass. Coupling between the pipe wall and the fluid as decreases the sound speed in the fluid. Likewise, the speed of sound in fluid is frequency-dependent, just as the group velocity of bending waves depends on the frequency. Wavelet transform of non-stationary sound signal was used to identify the frequency-dependent fluid sound speed. A time-frequency map, constructed by plotting the wavelet coefficient against the translation and scale parameters, shows an alteration in the low frequency waves. The so called “fluid mode” and “pipe mode” resonant frequencies are also clearly evident. Lastly, the impact of different pipe wall material properties is also shown. Wavelet analysis of the measured impulse response of a fluid-filled viscoelastic pipe provides useful tool for investigating its acoustical properties.

A Numerical Analysis on the Correlation Between Impact Conditions of Blood Drop on the Wall and its Resulting Bloodstain Pattern

2014 ◽  
Author(s):  
Geonkang Lee ◽  
Nahmkeon Hur ◽  
Young-Il Seo
Keyword(s):  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Crime Scene ◽  
Impact Angle ◽  
Fluid Viscosity ◽  
Interfacial Flows ◽  
Two Phase ◽  
Bloodstain Pattern ◽  
The Impact ◽  
Important Evidence

At the crime scene in case of homicide, spattered bloodstains at the incident site are important evidence. The patterns of the bloodstain on the floors and walls are determined by the impact conditions of blood drop such as drop size, impact angle and velocity. By analyzing the bloodstain pattern, one can retrace the origin of blood drops to reconstruct the crime scene. In the present study, motions of blood drop are analyzed to figure out the correlation between impact conditions of blood drop and bloodstain patterns. Two phase interfacial flows of blood drop impacting the wall are numerically simulated with the VOF method. To get the accurate results of bloodstains on the wall, non-Newtonian fluid viscosity and dynamic contact angle are used as the blood properties. By using these methods, patterns of bloodstains created from the blood drop are predicted for various Reynolds and Weber numbers.

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