Flow characteristic evaluation of two phase flow in microchannel

2017 ◽  
Vol 2017.25 (0) ◽  
pp. 316
Author(s):  
Kento TAKAHASHI ◽  
Shuhei NISHIBU ◽  
Yanrong LI ◽  
Terumi INAGAKI
Keyword(s):  
Flow Characteristic ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase

Numerical simulation of gas-solid flow characteristic of particles in fibrous media using OpenFOAM

2019 ◽  
Vol 29 (7) ◽  
pp. 921-930 ◽  
Author(s):  
Zhiyong Shu ◽  
Fuping Qian ◽  
Jinjing Zhu ◽  
Jinli Lu
Keyword(s):  
Numerical Simulation ◽  
Flow Characteristic ◽  
Two Phase Flow ◽  
Dendritic Structure ◽  
Filtration Efficiency ◽  
Pressure Differential ◽  
Phase Flow ◽  
Fibrous Media ◽  
Two Phase ◽  
Solid Flow

Euler-Lagrangian numerical simulation framework of gas-solid two-phase flow was used to simulate the gas-solid flow characteristic in fibrous media using OpenFOAM in this study. The simulation results were compared with the empirical model and CFD-DEM method. In addition, the deposition morphology of particles, pressure differential and filtration efficiency in unsteady stage and simulation cost were also analysed with OpenFOAM. The results show that OpenFOAM can simulate the process of gas-solid two-phase flow in the fibrous media, and the particles are agglomerated on the surface of fibrous media and form a dendritic structure similar to the experimental observation. The pressure differential in unsteady stage would increase with the mass per unit area. The filtration efficiency would increase with a corresponding increase in the amount of deposition, but the growth rate would decline gradually. Compared with CFD-DEM method, the simulation accuracy with OpenFOAM is slightly lower, especially in the case of large the Stokes number, but the simulation cost is low, too. Therefore, it is necessary to choose one of the two methods according to the actual situation.

Numerical Investigation on Two-Phase Flow Characteristic in the Separated Structure Shell-and-Tube Waste Heat Boiler

2017 ◽  
Author(s):  
Huaishuang Shao ◽  
Yungang Wang ◽  
Haidong Ma ◽  
Qinxin Zhao
Keyword(s):  
Void Fraction ◽  
Flow Characteristic ◽  
Two Phase Flow ◽  
Waste Heat ◽  
Phase Flow ◽  
Waste Heat Boiler ◽  
Shell Side ◽  
Two Phase ◽  
Saturated Water ◽  
Shell And Tube

The shell-and-tube waste heat boiler is a common facility to recover and utilize the energy of flue gas in industries. To improve the ability and efficiency of the boiler, a steam dome is configured above the drum so as to arrange more heat exchange tubes. Simulation and analysis of vapor-liquid two-phase flow across tube bundles arranged in the drum are of vital importance to design and safety operation. Numerical simulation of boiling two-phase flow across tube bundles in the drum was carried out to analyze the shell side thermal-hydraulics. Commercial software ANSYS FLUENT 14.5 was adopted for modeling and computational calculations. The applied modeling approach was validated against experimental results with a good agreement. In order to analyze the vapor-liquid two-phase flow performance under various working conditions, the inlet velocity of downcomer tubes of 3m·s−1, 4m·s−1 as well 5m·s−1 for saturated water were simulated, respectively. The pressure field, flow characteristic, void fraction distribution and heat transfer characteristic were analyzed to have a good knowledge of the boiler operation. The following conclusions have been drawn through analyzing simulation results. (1)The total pressure drop on shell side increased with increasing the inlet velocity of downcomer tubes of saturated water. (2)The velocity of saturated water decreased after flowing into the drum less than z = 0.1m as the flow area increasing, and then increased rapidly as the volume of the mixture two-phase flow increasing. (3)The integral average void fraction of the drum decreased as the mass flow rate of inlet saturated water increasing. (4)The HTC (heat transfer coefficient) of the heat exchange tubes varied with the flow direction, which is related to the vapor-water void fraction. The conclusions obtained above can be used as a reference for the design of the separated structure shell-and-tube waste heat recovery boiler.

Numerical Evaluation of Two-Phase Flow in Orthogonal Pipe under High Gravity

2013 ◽  
Vol 694-697 ◽  
pp. 626-629
Author(s):  
Yi Tao Liu ◽  
Bao Yin Song ◽  
Qiu Ping Yao
Keyword(s):  
Numerical Evaluation ◽  
Flow Characteristic ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Static Condition ◽  
Phase Flow ◽  
High Gravity ◽  
Two Phase ◽  
Gravity Condition ◽  
Pressure Distributions

In order to follow the technical progress in the filed of aeronautics and astronautics, a numerical investigation into flow characteristic of two-phase flow under high gravity (hi-g) condition is performed. Using the CFD code CFX, the two-phase flow in orthogonal pipe under high gravity condition has been evaluated, and the effects of hi-g on two-phase flow characteristic have been analyzed. Compared with the static condition, the flow pattern, volume fraction, velocity and pressure distributions, pressure drop through the pipe are quite different under hi-g, depending on the magnitude and direction.

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