Numerical simulation of single-phase flow in zinc fluidized bed furnace

2021 ◽  
Author(s):  
Kaile Tang ◽  
Ronghe Tan ◽  
Yanmei Chen
Keyword(s):  
Numerical Simulation ◽  
Fluidized Bed ◽  
Single Phase ◽  
Phase Flow ◽  
Single Phase Flow

Numerical Simulation of the Transient Flow in a Pump-Turbine During the Load Rejection Process With Special Emphasis on the Cavitation Effect

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Xiaolong Fu ◽  
Deyou Li ◽  
Hongjie Wang ◽  
Guanghui Zhang ◽  
Zhenggui Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Single Phase ◽  
Pressure Pulsation ◽  
Phase Flow ◽  
Cavitation Flow ◽  
Single Phase Flow ◽  
Pump Turbine ◽  
Cavitation Effect ◽  
Simulation Results ◽  
Load Rejection Process

Abstract At present, pumped-storage power technology is the only available and effective way for the load balancing and energy storage in the grid network scale. During the frequent switch back and forth conditions, there are severe pressure pulsation and cavitation in pump-turbines. However, their generation mechanism has not been determined yet. This work contributes to the numerical simulation of the transient behaviors in a prototype pump-turbine during the load rejection process with special emphasis on cavitation effect. In this study, the two-dimensional dynamic remesh and variable speed slide mesh methodologies were employed to perform the simulation of the transient single-phase flow and cavitation flow in a pump-turbine. The simulation results of single-phase flow and cavitation flow were both consistent with the experimental data except in local regions based on the experimental validation of prototype tests. However, the numerical results considering cavitation effects have a better behavior than those of single-phase flow in the predictions of pressure pulsation and rotational speed. Then, the cavitation flow simulation results were analyzed deeply, especially in pressure pulsation and cavitation flow field. Analysis revealed that three typical complex frequency components of pressure were captured in the cavitation flow, which significantly affect the axial hydraulic thrust on the runner. And it is validated that they are primarily induced by the cavity collapse near the trailing edges of the runner blades in reverse pump mode and the interaction between cavitation and vortex rope in draft-tube in turbine mode.

Numerical Analysis of the Flow Field in the Nozzle of Hot Water Rocket Motor

2014 ◽  
Vol 1016 ◽  
pp. 635-639 ◽  
Author(s):  
Wei Wei Sun ◽  
Zhi Jun Wei
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Flow Field ◽  
Single Phase ◽  
Rocket Motor ◽  
Hot Water ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Working Process ◽  
Flow Process

Flashing is an important factor in the working process of hot water rocket motor. In order to deeply understand the performance characteristic of hot water rocket motor, a numerical simulation model of the flow field in the nozzle was established in this paper. According to the study of flow field in the nozzle of the motor,it is found that the phase change occurs at the position of the throat,and the flow reaches to supersonic after the throat because of the changing sound speed.The flow in the nozzle can be divided into three processes in this paper: single-phase flow process, flash process and expand-accelerating process.

scholarly journals Numerical Simulation of a Single-Phase Flow Through Fractures with Permeable, Porous and Non-Ductile Walls

2017 ◽  
Vol 7 (5) ◽  
pp. 2041-2046
Author(s):  
N. Pour Mahmoud ◽  
A. Zabihi
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Single Phase ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Surrounding Area ◽  
Fracture Geometry ◽  
Pressure Drops ◽  
Permeable Walls ◽  
Flow Through

This paper attempts to study flows within fractures through a set of numerical simulations. In addition, a special care is given to hydraulic features and characteristics of fractures. The research is performed through the application of calculative fluid dynamics and a finite volume discrete schema. The investigated flows are laminar, single-phase and stable flows of water and air through fractures with penetrable walls. The selected fracture geometry is inspired from the tomographic scan of a stone fracture. Water and air are modeled in fractures with permeable walls and different permeability levels. It has been observed that in case of permeable matrixes, the friction coefficient is lower compared to impermeable matrixes. In fact permeability reduced friction. In addition, highest pressure drops were observed in areas with smaller fracture diaphragms. Nonetheless, the surrounding area of the fracture is analyzed with the consideration of Darcy's rule.

Numerical simulation of single-phase flow in a single square tube with blockage

2021 ◽  
Vol 44 ◽  
pp. 101053
Author(s):  
Daheng Li ◽  
Yun Guo ◽  
Hui Bao ◽  
Jun Xiao ◽  
Changhong Peng
Keyword(s):  
Numerical Simulation ◽  
Single Phase ◽  
Phase Flow ◽  
Single Phase Flow

scholarly journals Mass transfer from the wall of a column to the fluid in a fluidized bed of inert spherical particles

2004 ◽  
Vol 58 (2) ◽  
pp. 69-72
Author(s):  
Danica Brzic ◽  
Nevenka Boskovic-Vragolovic ◽  
Zeljko Grbavcic
Keyword(s):  
Mass Transfer ◽  
Reynolds Number ◽  
Benzoic Acid ◽  
Fluidized Bed ◽  
Fluidized Beds ◽  
Single Phase ◽  
Spherical Particles ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Transfer Coefficients

Mass transfer in fluidized beds is an important operation for separation processes. Two effects can be achieved by using fluidized beds in mass transfer processes increasing interface area and relative movement between the phases. These effects are both desirable because they lead to greater process rates. This paper presents an experimental investigation regarding mass transfer from the wall of a column to the fluid in a fluidized bed of inert spherical particles. The experiments were conducted in column 40 mm in diameter with spherical particles 0,8-3 mm in diameter and water as one fluidizing fluid. The method of dissolution of benzoic acid was used to provide very low mass flux. The average wall-to-fluid mass transfer coefficients were determined for two systems: single-phase fluid flow and a fluidized bed of inert particles The measurements encompassed a Reynolds number range from 100-4000 for single-phase flow and 600-4000 in fluidized beds. The mass transfer coefficients for both systems were calculated from weight loss of benzoic acid. The effects of superficial liquid velocity and particle diameter on the mass transfer coefficient were investigated. It was found that mass transfer was more intensive in the fluidized bed in comparison with single phase flow. The best conditions for mass transfer were reached at a minimum fluidization velocity, when the mass transfer coefficient had the greatest value. The experimental data were correlated in the form: jd = f(Re), where jd is the dimensionless mass transfer factor and Re the Reynolds number.

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