A new centrifugal correction drag force model for gas solid-particle two-phase flow

2016 ◽  
Vol 303 ◽  
pp. 124-129 ◽  
Author(s):  
Zhi Shang
Keyword(s):  
Solid Particle ◽  
Drag Force ◽  
Two Phase Flow ◽  
Force Model ◽  
Phase Flow ◽  
Two Phase

Experiment and Numerical Simulation of Bubble Behaviors in Argon Gas Injection Into Lead-Bismuth Pool

2006 ◽  
Author(s):  
Yumi Yamada ◽  
Toyou Akashi ◽  
Minoru Takahashi
Keyword(s):  
Direct Contact ◽  
Two Phase Flow ◽  
Experimental Result ◽  
Feed Water ◽  
Force Model ◽  
Phase Flow ◽  
Two Dimensional ◽  
Two Phase ◽  
Argon Gas ◽  
Bubble Rising

In a lead-bismuth alloy (45%Pb-55%Bi) cooled direct contact boiling water fast reactor (PBWFR), steam can be produced by direct contact of feed water with primary Pb-Bi coolant in the upper core plenum, and Pb-Bi coolant can be circulated by buoyancy forces of steam bubbles. As a basic study to investigate the two-phase flow characteristics in the chimneys of PBWFR, a two-dimensional two-phase flow was simulated by injecting argon gas into Pb-Bi pool in a rectangular vessel (400mm in length, 1500mm in height, 50mm in width), and bubble behaviors were investigated experimentally. Bubble sizes, bubble rising velocities and void fractions were measured using void probes. Argon gas was injected through five nozzles of 4mm in diameter into Pb-Bi at two locations. The experimental conditions are the pressure of atmospheric pressure, Pb-Bi temperatures of 443K, and the flow rate of injection Ar gas is 10, 20, and 30 NL/min. The measured bubble rising velocities were distributed in the range from 1 to 3 m/s. The average velocity was about 0.6 m/s. The measured bubble chord lengths were distributed from 1mm up to 30mm. The average chord length was about 7mm. An analysis was performed by two-dimensional and two-fluid model. The experimental results were compared with the analytical results to evaluate the validity of the analytical model. Although large diameter bubbles were observed in the experiment, the drag force model for spherical bubbles performed better for simulation of the experimental result because of high surface tension force of Pb-Bi.

Experimental and Numerical Study on Solid Particle Erosion in Elbows Mounted in Series

2017 ◽  
Author(s):  
Alireza Asgharpour ◽  
Peyman Zahedi ◽  
Hadi Arabnejad Khanouki ◽  
Siamack A. Shirazi ◽  
Brenton S. McLaury
Keyword(s):  
Solid Particle ◽  
Two Phase Flow ◽  
Numerical Study ◽  
Flow Direction ◽  
Solid Particle Erosion ◽  
Phase Flow ◽  
Particle Erosion ◽  
Two Phase ◽  
Experimental Conditions ◽  
In Series

Solid particle erosion in elbows is of great importance in the pipeline design process. In many situations, elbows are mounted in series with small distances between each other. Due to changes in flow direction and particles concentration after the first elbow, a significant change in erosion magnitude and pattern in the downstream elbows (second elbow) might be expected. The aim of this study is to investigate the solid particle erosion behavior in the second elbow. In the experimental study using a state-of-art ultrasonic technique, erosion magnitudes in two standard 4-inch elbows separated by a distance of 10 pipe diameter have been measured. Experiments have been conducted in single and two-phase flow regimes for different particle sizes and gas and liquid velocities. In most of the cases, the maximum erosion in the second elbow was less than the first elbow, and the erosion pattern in the second elbow was slightly different than the first elbow. Comparison of single and two-phase flow results for both elbows revealed that in two-phase flow regime a major reduction in erosion magnitude happens as a results of the presence of liquid in the pipe. Additionally, for further considerations, the experimental conditions have been simulated numerically using ANSYS FLUENT software. Simulations have been performed for different mesh grids and turbulence models to examine how they influence the erosion in the second elbow as both can affect the particles trajectories. The accuracy of the numerical results are evaluated with available experimental data. For most of the cases, the erosion predictions are in a good agreement with experimental results. For both elbows by increasing the gas velocity and particle size, the maximum erosion increased.

scholarly journals Numerical simulation of predicting and reducing solid particle erosion of solid-liquid two-phase flow in a choke

2009 ◽  
Vol 6 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Guomei Li ◽  
Yueshe Wang ◽  
Renyang He ◽  
Xuewen Cao ◽  
Changzhi Lin ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Solid Particle ◽  
Two Phase Flow ◽  
Solid Particle Erosion ◽  
Phase Flow ◽  
Particle Erosion ◽  
Two Phase ◽  
Solid Liquid

Implementation and Validation of an Improved Interfacial Area Concentration Model for Two-Phase Flow CFD Simulations

2021 ◽  
Author(s):  
Xiang Zhang ◽  
Minjun Peng ◽  
Tenglong Cong ◽  
Chuan Lu ◽  
Chenyang Wang
Keyword(s):  
Drag Force ◽  
Drift Velocity ◽  
Cfd Simulation ◽  
Two Phase Flow ◽  
Interfacial Area ◽  
Phase Flow ◽  
Two Phase ◽  
Interfacial Area Concentration ◽  
Boiling Flow ◽  
Improved Model

Abstract The interfacial area concentration (IAC) is an important parameter in the calculation of interfacial transfers in two-fluid model, which can affect the accuracy of the boiling simulations. In this paper, an improved IAC model based on drag force and drift velocity is obtained, which can make full use of the experimental data and the models of the drag force and the drift velocity to avoid the shortage of IAC algebraic model in two-phase flow simulations theoretically. The improved model is validated by the DEBORA boiling flow experiment data. The reasonable radial distributions of void fraction, liquid temperature and phase velocity can be obtained, which indicates that the improved IAC model coupled in boiling flow model can be applied in CFD simulation of two-phase boiling flow. The improved model provides a new calculation approach for the IAC in the boiling flow with multi flow regimes.

21013 Study on Solid Particle Transport Using Gas-liquid Two-Phase Flow

2010 ◽  
Vol 2010.16 (0) ◽  
pp. 355-356
Author(s):  
Masaki MOTOHASHI ◽  
Hiroyasu OHTAKE ◽  
Yasuo KOIZUMI
Keyword(s):  
Solid Particle ◽  
Particle Transport ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase

Evaluation of the Sensitivity of a Two-Phase Flow Model for the Steam Separators Analysis

2006 ◽  
Author(s):  
Masao Chaki ◽  
Michio Murase
Keyword(s):  
Two Phase Flow ◽  
Natural Circulation ◽  
Core Stability ◽  
Force Model ◽  
Phase Flow ◽  
High Power Density ◽  
Two Phase ◽  
Pressure Losses ◽  
Swirl Vane ◽  
Steam Separator

Reducing of the pressure losses of steam separator systems of boiling water reactor (BWR) plants is useful to reduce the required pump head and enhance core stability design margin. The need to reduce the pressure losses of steam separator systems is especially important in BWR plants that have high power density cores and natural circulation systems. The core flow rate of a BWR plant with a natural circulation system is affected by the pressure losses of steam separator systems. In BWR plants with high power density cores, the core stability design margin is affected by these pressure losses. Generally, reducing the pressure losses of the steam separator systems leads to increased carry-under and carryover. Reducing the pressure losses while keeping the characteristics of both carry-under and carryover is desired, so many studies have been done. The steam separator of a BWR plant consists of a standpipe section, a swirl vane section and three-barrel sections. Two-phase flow of steam and water enters the steam separator through the standpipe section and reaches the swirl vane section. In the swirl vane section, the two-phase flow is given centrifugal force and is basically separated into steam and water. Therefore investigating the two-phase flow characteristics of the swirl vane section is very important. After the swirl vane section, the two-phase flow enters the barrel sections. Each barrel has a pick-off ring. The water in the barrel section is mainly removed by these pick-off rings because the water mainly flows upward as a liquid film in the barrel section due to the centrifugal force given in the swirl vane section. We researched the effect of using the drag force model of the swirling two-phase flow in analyzing a steam separator and we found that the drag force model greatly affects the results of the analysis.

Drag force in dense gas-particle two-phase flow

2003 ◽  
Vol 19 (3) ◽  
pp. 228-234 ◽  
Author(s):  
You Changfu ◽  
Qi Haiying ◽  
Xu Xuchang
Keyword(s):  
Drag Force ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Dense Gas ◽  
Two Phase
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