scholarly journals Research on the Wear Characteristics of a Bend Pipe with a Bump Based on the Coupled CFD-DEM

2021 ◽  
Vol 9 (6) ◽  
pp. 672
Author(s):  
Yi Li ◽  
Jianpeng Cao ◽  
Chaojie Xie
Keyword(s):  
Wear Rate ◽  
Two Phase Flow ◽  
Pipe Wall ◽  
Phase Flow ◽  
Two Phase ◽  
Bend Pipe ◽  
Computational Fluid Dynamics Cfd ◽  
Reduction Effect ◽  
Lifting System ◽  
Solid Liquid

In the process of hydraulic lifting of solid mineral particles on the seabed, the two-phase flow in the pipeline causes wall wear, which reduces the reliability of the hydraulic lifting system. In this research, based on the coupled computational fluid dynamics (CFD) and discrete element method (DEM), the numerical simulation of large particle solid–liquid two-phase flow and wall wear in a bend pipe with different wall shapes was conducted to provide solutions for reducing wall wear. By adding bumps to the bend pipe wall to change the shape of its inner wall, under the working conditions of particle concentrations of 1–10% and particle sizes of 1–3 mm, wear experiments and calculations for the bend pipe with bumps at different positions were performed. With comparative analysis, it was found that the location of the bump in the bend pipe had an important influence on the maximum wear rate. When the bump was located near the location where the particles collided with the prototype bend pipe for the first time, the maximum wear rate decreased the most significantly. The particle mass flow rate will also affect the wear reduction effect of the bump on the bend pipe wall.

scholarly journals Clustering-Based Component Fraction Estimation in Solid–Liquid Two-Phase Flow in Dredging Engineering

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5697
Author(s):  
Chang Sun ◽  
Shihong Yue ◽  
Qi Li ◽  
Huaxiang Wang
Keyword(s):  
Clustering Algorithm ◽  
Two Phase Flow ◽  
Low Cost ◽  
Fast Response ◽  
New Method ◽  
Phase Flow ◽  
Reference Distribution ◽  
Two Phase ◽  
Long Time ◽  
Solid Liquid

Component fraction (CF) is one of the most important parameters in multiple-phase flow. Due to the complexity of the solid–liquid two-phase flow, the CF estimation remains unsolved both in scientific research and industrial application for a long time. Electrical resistance tomography (ERT) is an advanced type of conductivity detection technique due to its low-cost, fast-response, non-invasive, and non-radiation characteristics. However, when the existing ERT method is used to measure the CF value in solid–liquid two-phase flow in dredging engineering, there are at least three problems: (1) the dependence of reference distribution whose CF value is zero; (2) the size of the detected objects may be too small to be found by ERT; and (3) there is no efficient way to estimate the effect of artifacts in ERT. In this paper, we proposed a method based on the clustering technique, where a fast-fuzzy clustering algorithm is used to partition the ERT image to three clusters that respond to liquid, solid phases, and their mixtures and artifacts, respectively. The clustering algorithm does not need any reference distribution in the CF estimation. In the case of small solid objects or artifacts, the CF value remains effectively computed by prior information. To validate the new method, a group of typical CF estimations in dredging engineering were implemented. Results show that the new method can effectively overcome the limitations of the existing method, and can provide a practical and more accurate way for CF estimation.

scholarly journals Flow Structures in Vertical Solid-liquid Two-phase Flow under Microgravity Environment

2007 ◽  
Vol 27 (Supplement1) ◽  
pp. 109-110
Author(s):  
Junichi UEMATSU ◽  
Kazuya ABE ◽  
Xiaoran YU ◽  
Tatsuya HAZUKU ◽  
Masaki OSHIMA ◽  
...  
Keyword(s):  
Two Phase Flow ◽  
Microgravity Environment ◽  
Flow Structures ◽  
Phase Flow ◽  
Two Phase ◽  
Solid Liquid

scholarly journals Mass transfer between particles and liquid in solid-liquid two-phase flow through horizontal tubes.

1982 ◽  
Vol 15 (4) ◽  
pp. 311-313 ◽  
Author(s):  
HIROYASU OHASHI ◽  
TAKUO SUGAWARA ◽  
KEN-ICHI KIKUCHI ◽  
MORITO TAKEDA
Keyword(s):  
Mass Transfer ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Horizontal Tubes ◽  
Flow Through ◽  
Solid Liquid

Comparison of four types of membrane bioreactor systems in terms of shear stress over the membrane surface using computational fluid dynamics

2013 ◽  
Vol 68 (12) ◽  
pp. 2534-2544 ◽  
Author(s):  
N. Ratkovich ◽  
T. R. Bentzen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Membrane Fouling ◽  
Two Phase Flow ◽  
Membrane Surface ◽  
Cross Flow ◽  
Membrane Bioreactors ◽  
Phase Flow ◽  
Two Phase ◽  
Computational Fluid Dynamics Cfd

Membrane bioreactors (MBRs) have been used successfully in biological wastewater treatment to solve the perennial problem of effective solids–liquid separation. A common problem with MBR systems is clogging of the modules and fouling of the membrane, resulting in frequent cleaning and replacement, which makes the system less appealing for full-scale applications. It has been widely demonstrated that the filtration performances in MBRs can be greatly improved with a two-phase flow (sludge–air) or higher liquid cross-flow velocities. However, the optimization process of these systems is complex and requires knowledge of the membrane fouling, hydrodynamics and biokinetics. Modern tools such as computational fluid dynamics (CFD) can be used to diagnose and understand the two-phase flow in an MBR. Four cases of different MBR configurations are presented in this work, using CFD as a tool to develop and optimize these systems.

Flow Pattern of Gas-Liquid Two-Phase Flow in a Horizontal U bend Pipe

1995 ◽  
pp. 407-416
Author(s):  
T. Sakaguchi ◽  
S. Hosokawa ◽  
Y. Fujii ◽  
H. Minagawa ◽  
N. Nakamori ◽  
...  
Keyword(s):  
Flow Pattern ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Bend Pipe

Solid–liquid two-phase flow and erosion calculation of butterfly valves at small opening based on DEM method

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Benliang Xu ◽  
Zuchao Zhu ◽  
Zhe Lin ◽  
Dongrui Wang
Keyword(s):  
Peer Review ◽  
Two Phase Flow ◽  
Solid Particles ◽  
Phase Flow ◽  
Butterfly Valve ◽  
Two Phase ◽  
Content Type ◽  
Small Opening ◽  
Solid Liquid ◽  
The Impact

Purpose The study aims to decrease the effect of solid particles on a butterfly valve, which will cause seal failure and leakage, providing a reference for anti-wear design. Design/methodology/approach In this paper, computational fluid dynamics discrete element method (CFD-DEM) simulation was conducted to study the solid–liquid two-phase flow characteristics and erosion characteristics of a butterfly valve with a different opening. Findings Abrasion at 10% opening is affected by high-speed jets in upper and lower parts of the pipeline, where the erosion is intense. The impact of the jet on the upper part of 20% opening begins to weaken. With the top backflow vortex disappearing, the effect of lower jet is enhanced. Meanwhile, the bottom backflow vortex phenomenon is obvious, and the abrasion position moves downward. At 30% opening, the velocity is further weakened, and the circulation effect of lower flow channel is more obvious than that of the upper one. Originality/value It is the first time to use DEM to investigate the two-phase flow and erosion characteristics at a small opening of a butterfly valve, considering the effect of inter-particle collision. Therefore, this study carries on the thorough analysis and discussion. At the same opening degree, with increasing of the particle size, the abrasion of valve frontal surface increases when the size is less than 150 µm and decreases when it is greater than 150 µm. For the valve backflow surface, this boundary value becomes 200 µm. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0264/

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