CFD Simulation of the Liquid-Column Flow Field of Double Contact

2012 ◽  
Vol 610-613 ◽  
pp. 1915-1919
Author(s):  
Li Jun Fang ◽  
Yan Chao Chang
Keyword(s):  
Pressure Drop ◽  
Flow Field ◽  
Gas Flow ◽  
Cfd Simulation ◽  
Equation Model ◽  
Liquid Column ◽  
Test Results ◽  
Two Phase ◽  
Simulation Calculation ◽  
Contact Liquid

It is found that the increase in the number of nozzle will lead to overall pressure drop in the tower when there is no fluid column jet and in this process RNG double equation model was used to describes gas phase turbulence, by means of simulation calculation of the gas-liquid two phase flow field in double contact liquid-column tower. In the stage of liquid column jet, with the increasing of the number of nozzle pressure drop range reduced, but phase change is more apparent, flow field distribution in the tower tends to be evenly. Through the numerical simulation of the particular condition, gas flow condition was described in conditions of different nozzle number and different liquid air ratio. Calculation is well agreed with test results, which show that the model and the algorithm has good predictive and reliability.

CFD Simulation of Two-Phase Flow in a Downhole Venturi Meter

2011 ◽  
Vol 130-134 ◽  
pp. 3644-3647
Author(s):  
Ding Feng ◽  
Si Huang ◽  
Yu Hui Guan ◽  
Wei Guo Ma
Keyword(s):  
Optimal Design ◽  
Pressure Drop ◽  
Flow Field ◽  
Cfd Simulation ◽  
Two Phase Flow ◽  
Flow Simulation ◽  
Phase Flow ◽  
Feed Flow Rate ◽  
Two Phase ◽  
Oil Water

This work performs an oil-water two-phase flow simulation in a downhole Venturi meter to investigate the flow field and pressure characteristics with different flow and oil-water ratios. The relation between the pressure drop and the feed flow rate in the flowmeter is investigated for its optimal design.

Experimental Study on Flow Field Characteristic of Bag Filter

2012 ◽  
Vol 508 ◽  
pp. 254-258 ◽  
Author(s):  
Hai Ming Fu ◽  
You Jun Zhao
Keyword(s):  
Flow Field ◽  
Gas Flow ◽  
Cfd Simulation ◽  
Collection Efficiency ◽  
Flow Distribution ◽  
Filtration Velocity ◽  
Experimental Result ◽  
Test Results ◽  
Bag Filter ◽  
Filter Structure

In order to select best filtration velocity of bag filters and to improve gas flow distribution, to increase collection efficiency and to reduce operation resistance, gas flow distribution was tested by using hot-wire anemometer, CFD simulation was made and basic accordant result was obtained by comparing simulation result with experimental result. Test results and analysis showed that: Uneven distribution of flow field was caused by jet flow, critical filtration velocity exited in flow field distribution. Improving measure of flow field and optimize method of bag filter structure was putted out.

Two-Phase Flows in Mini-/Micro-Gas Flow Channels of PEM Fuel Cells

2013 ◽  
Author(s):  
Sung Chan Cho ◽  
Yun Wang
Keyword(s):  
Pressure Drop ◽  
Gas Flow ◽  
Fluid Model ◽  
Pem Fuel Cells ◽  
Two Phase ◽  
Micro Gas Flow ◽  
Two Fluid Model ◽  
The Impact ◽  
Two Fluid ◽  
Phase Pressure

In this paper, two-phase flow dynamics in a micro channel with various wall conditions are both experimentally and theoretically investigated. Annulus, wavy and slug flow patterns are observed and location of liquid phase on different wall condition is visualized. The impact of flow structure on two-phase pressure drop is explained. Two-phase pressure drop is compared to a two-fluid model with relative permeability correlation. Optimization of correlation is conducted for each experimental case and theoretical solution for the flows in a circular channel is developed for annulus flow pattern showing a good match with experimental data in homogeneous channel case.

CFD simulation of air effect on flow field characteristics of hydro-viscous clutch with constant speed difference

2018 ◽  
Vol 19 (2) ◽  
pp. 208
Author(s):  
Xudong Zheng ◽  
Fangwei Xie ◽  
Diancheng Wu ◽  
Xinjian Guo ◽  
Bing Zhang ◽  
...  
Keyword(s):  
Flow Field ◽  
Cfd Simulation ◽  
Power Transmission ◽  
Volume Fraction ◽  
Phase Distribution ◽  
Constant Speed ◽  
Distribution Law ◽  
Two Phase ◽  
Oil Film ◽  
Speed Difference

The purpose of this paper is to study the air effects on transmission characteristics of hydro-viscous clutch and reveal the distribution law of the flow field of the oil film. The computational-fluid-dynamics (CFD) simulation model of oil film with radial oil grooves between friction pairs is taken as the study object. Considering the air effects, the pressure field, two-phase distribution, transmission torque and temperature field of the oil film are analyzed comparatively by using the CFD technology. The results show that the presence of air changes the pressure and temperature distributions of the oil film. With increase of the absolute rotational speed, the air volume fraction increases and the radius value of the air-liquid boundary decreases under condition of constant speed difference, which makes the coverage rate of the oil film on the surface of the friction disks reduce and the transmission torque of the oil film decrease. These simulation results are attributed to the study of hydro-viscous-drive and its applications. This paper also can provide a theoretical basis for the mechanism of power transmission through oil film in the presence of air effects.

Analysis of Pressure Drop and Water Flooding of Two-Phase Flow Along Channels for a PEM Fuel Cell System

2009 ◽  
Author(s):  
Jinglin He ◽  
Song-Yul Choe ◽  
Chang-Ouk Hong
Keyword(s):  
Fuel Cell ◽  
Pressure Drop ◽  
Relative Humidity ◽  
Liquid Water ◽  
Water Distribution ◽  
Gas Flow ◽  
Pem Fuel Cell ◽  
Cell System ◽  
Water Flooding ◽  
Two Phase

The flow in gas flow channels of an operating polymer electrolyte membrane (PEM) fuel cell has a two-phase characteristic that includes air, water vapor and liquid water and significantly affects the water flooding, pressure distribution along the channels, and subsequently the performance of the cell and system. Presence of liquid water in channels prevents transport of the reactants to the catalysts and increases the pressure difference between the inlet and outlet of channels, which leads to high parasitic power of pumps used in air and fuel supply systems. We propose a model that enables prediction of pressure drop and liquid water distribution along channels and analysis of water flooding in an operating fuel cell. The model was developed based on a gas-liquid two-phase separated flow that considers the variations of gas pressure, mass flow rate, relative humidity, viscosity, void fraction, and density along the channels on both sides. Effects of operating parameters that include stoichoimetric ratio, relative humidity, and inlet pressure on the pressure drop and water flooding along the channels were analyzed.

Experimental Visualization and Numerical Simulation of Liquid-Gas Two-Phase Flows in a Horizontal Pipe

2017 ◽  
Author(s):  
Milad Darzi ◽  
Chanwoo Park
Keyword(s):  
Numerical Simulation ◽  
Gas Flow ◽  
Cfd Simulation ◽  
Glass Tube ◽  
Flow Patterns ◽  
Two Phase Flows ◽  
Two Phase ◽  
Mixture Flow ◽  
Horizontal Pipe ◽  
Flow Rates

This paper presents the results of both visualization experiment and numerical simulation for two-phase (water-air mixture) flows in a horizontal tube. A visualization experimental setup was used to observe various two-phase flow patterns for different flow rates of water/air mixture flow in a glass tube of 12 mm in diameter. Total of 303 experimental data points were compared with Mandhane’s flow map. Most of the data for stratified, plug and slug flows were found to be in good agreement. However, annular flow was observed for relatively lower gas flow rates and also wavy flow occurred at relatively higher liquid flow rates in this experiment. A three-dimensional Computational Fluid Dynamics (CFD) simulation was performed using OpenFOAM employing “interFoam” as the solver to simulate the two-phase flows in horizontal pipe based on Volume-Of-Fluid (VOF) method. The simulated and experimentally observed flow patterns for the same set of superficial velocities shows acceptable similarities for stratified, wavy, plug, slug and annular flows. Also, the computed values of the void fraction and pressure drop for the numerical simulations shows reasonable agreement with well-known correlations in literature.

scholarly journals Simulation and experimental research based on carrier gas flow rate on the influence of four-channel coaxial nozzle flow field

2020 ◽  
pp. 002029402096423
Author(s):  
Shi Rui Guo ◽  
Qian Qian Yin ◽  
Lu Jun Cui ◽  
Xiao Lei Li ◽  
Ying Hao Cui ◽  
...  
Keyword(s):  
Flow Field ◽  
Gas Flow ◽  
Simulation Analysis ◽  
Two Phase ◽  
Carrier Gas ◽  
Coaxial Nozzle ◽  
Convergence Point ◽  
Flow Convergence ◽  
Fluent Software ◽  
Carrier Gas Flow

This paper investigates the influence of carrier gas flow on the external flow field of coaxial powder feeding nozzle. FLUENT software was adopted to establish gas-solid two-phase flow. The simulation of powder stream field under different carrier gas flow was also carried out. Results show that the larger the flow of carrier gas is, the higher the gas flow field velocity at the nozzle outlet is. At the same time, the concentration at the convergence point is lower, and the convergent point is maintained at 0.015 m. Under the condition of 4 L/min, the powder flow convergence is good. When it exceeds 4 L/min, powder spot diameter increases. The experiment of powder aggregation and laser cladding forming were completed, which shows that the forming effect is the best one under the condition of 4 L/min. It is consistent with the simulation analysis results and has a high reference to the optimization of the process parameters of coaxial nozzle.

Advanced Integrated Flow Field (IFF) Design for High Performance Fuel Cell and Electrolyzer

2014 ◽  
Author(s):  
Michael Pien ◽  
Steven Lis ◽  
Radha Jalan ◽  
Marvin Warshay ◽  
Suresh Pahwa
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Flow Field ◽  
Gas Flow ◽  
Pem Fuel Cells ◽  
Water Flooding ◽  
Stoichiometric Ratio ◽  
Plant Design ◽  
Two Phase ◽  
Hydrophilic Matrix

Higher efficiency operation of PEM fuel cells needs an advanced passive way to remove product water. Water flooding in gas flow channels reduces efficiency and needs to be mitigated by a support of balance of plant design and components which results in parasitic power losses. ElectroChem’s Integrated Flow Field (IFF) design with the integration of hydrophobic and hydrophilic matrix has been proven to solve these challenges with no impact on the performance. The hydrophobic and hydrophilic matrix facilitates two phase (gas and liquid) flow to and away from the interface between the electrode membrane assembly and the flow field. A phase-separation feature of the IFF allowed the fuel cells to operate on a flow rate at its consumption rate. The IFF fuel cell has demonstrated operation at the ideal one stoichiometric ratio with 100% gas utilization and orientation independent. The IFF also served as gas humidifier through the creation of simultaneous distribution of gas and water within the cell. The self-humidification capability keeps the cell operating without the humidity of the input gas. The IFF design also enhanced the performance of water electrolysis which is a reverse process of fuel cell. The IFF supported the passive water feed to the cell and gas separation from the cell.

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