scholarly journals Interaction and influence of a flow field and particleboard particles in an airflow forming machine with a coupled Euler-DPM model

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253311
Author(s):  
Jian Zhang ◽  
Qing Chen ◽  
Minghong Shi ◽  
Hongping Zhou ◽  
Linyun Xu
Keyword(s):  
Flow Field ◽  
Raw Materials ◽  
Characteristic Point ◽  
Continuous Production ◽  
Internal Flow ◽  
Technical Difficulty ◽  
Calculation Model ◽  
Two Phase ◽  
Flow Field Characteristics ◽  
Uniform Diameter

Particleboards are widely used in the artificial board market, which can be constructed from a variety of raw materials and require small amounts of energy to be produced. In the particleboard production process, forming machines play an important role as the key equipment for achieving continuous production. In recent years, airflow forming machines have received increasing attention in particleboard production lines because of their strong separation ability and low price. However, the internal flow field is complex and difficult to control, which affects the surface quality and strength of the particleboard. The most pressing technical difficulty is controlling the flow field characteristics of the airflow paver. At present, the research on this subject is conducted primarily through repeated experiments, which entail long research periods and high processing costs. To reduce human and financial costs, in this study, Computational Fluid Dynamics (CFD) is employed to investigate the flow field and the gas-solid two-phase flow field coupled with particle movement of an airflow forming machine. The accuracy of the calculation model is verified by comparing characteristic point velocities obtained from experimental analysis and a simulation. The simulation results show that in practical production, the frequency of a negative pressure fan should be greater than 27 Hz. It is necessary to set the shoulder properly, and the slab smoothness can be improved by moving the shoulder back on the premise of meeting the strength requirements of the box. The distance between the shoulders of the box body should be less than 2570 mm, and particles with uniform diameter should be added to the paving box to reduce the turbulence effect, improve the quality of particle forming and provide actual particleboard production with a solid theoretical foundation.

Numerical Analysis of Flow Field Characteristics in Three-Z-Shaped Ultrasonic Flowmeter

2012 ◽  
Vol 226-228 ◽  
pp. 1829-1834 ◽  
Author(s):  
Jing Yuan Tang ◽  
Jian Ming Chen ◽  
Hong Bin Ma ◽  
Guang Yu Tang
Keyword(s):  
Flow Field ◽  
Cross Sections ◽  
Flow Direction ◽  
Fluid Velocity ◽  
Internal Flow ◽  
Reynolds Stress Model ◽  
Ultrasonic Flowmeter ◽  
Developed Turbulence ◽  
Fluid Field ◽  
Flow Field Characteristics

The flow field characteristics in U-typed bend has been extensively studied for transit time ultrasonic flowmeters designing, but for the flowmeter with three-Z-shaped round pipe there is still lack of corresponding research. This paper presents a computational fluid dynamics (CFD) approach for modeling of the three-Z-shaped ultrasonic flowmeter and studying of internal fluid field characteristics based on Reynolds stress model (RSM). The fluid velocity profile in the three ultrasound path is obtained using CFD and secondary flow in cross section also is analyzed. The simulation results show that the internal flow fields in the flowmeter are not fully developed turbulence with asymmetric axial velocity distribution and dramatic changes along the flow direction, and there are obvious secondary cross flows on theirs cross-sections. The CFD simulations provide useful insights into the flow field associated with ultrasonic flowmeters design.

scholarly journals Study on Propellers Distribution and Flow Field in the Oxidation Ditch Based on Two-Phase CFD Model

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2506 ◽  
Author(s):  
Yuquan Zhang ◽  
Chengyi Li ◽  
Yanhe Xu ◽  
Qinghong Tang ◽  
Yuan Zheng ◽  
...  
Keyword(s):  
Flow Field ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Dead Zone ◽  
Production Costs ◽  
Oxidation Ditch ◽  
Cfd Model ◽  
Two Phase ◽  
Flow Field Characteristics ◽  
Increasing Demand

The oxidation ditch (OD) plays an important role in wastewater treatment plants. With increasing demand and production costs, the energy consumption and sludge deposition occurring in the OD must be diminished to enhance its development. In this paper, a two-phase computational fluid dynamics (CFD) model of water and activated sludge examined the flow field characteristics of an OD, consisting of two side-by-side propellers. The system was studied under five configurations, where the spacing between the propellers was set equal to −0.2, −0.1, 0, 0.1, 0.2 times the length of the OD. The viscosity and settling rate of activated sludge was imported in the numerical simulation through a user defined function (UDF). The optimal scheme of the propeller’s power consumption, velocity distribution, and sludge concentration distribution was obtained. The result shows that sludge concentrations are linked with dead zone velocity but not necessarily with low velocities. Experiments confirmed the validity of the velocity flow field simulated by the two-phase CFD model. Overall, these findings form the basis for the propellers distribution optimization and allow a deeper insight into the flow field of OD systems.

Research Analysis and Experiment Study on Flow Field of Hydrodynamic Coupling

2011 ◽  
Vol 418-420 ◽  
pp. 2006-2011
Author(s):  
Rui Zhang ◽  
Cheng Jian Sun ◽  
Yue Wang
Keyword(s):  
Flow Field ◽  
Cfd Simulation ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Internal Flow ◽  
Phase Flow ◽  
Complex Flow ◽  
Two Phase ◽  
Operation Conditions ◽  
Hydrodynamic Coupling

CFD simulation and PIV test technology provide effective solution for revealing the complex flow of hydrodynamic coupling’s internal flow field. Some articles reported that the combination of CFD simulation and PIV test can be used for analyzing the internal flow field of coupling, and such analysis focuses on one-phase flow. However, most internal flow field of coupling are gas-fluid two-phase flow under the real operation conditions. In order to reflect the gas-fluid two-phase flow of coupling objectively, CFD three-dimensional numerical simulation is conducted under two typical operation conditions. In addition, modern two-dimensional PIV technology is used to test the two-phase flow. This method of combining experiments and simulation presents the characteristics of the flow field when charging ratios are different.

Liquid Jet Impingement on a Free Liquid Surface: PIV Study of the Turbulent Bubbly Two-Phase Flow

2010 ◽  
Author(s):  
Khaled J. Hammad
Keyword(s):  
Flow Field ◽  
Two Phase Flow ◽  
Jet Impingement ◽  
Flow Region ◽  
Air Entrainment ◽  
Continuous Phase ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Field Characteristics ◽  
Inflow Conditions

The turbulent two-phase flow arising from the normal impingement of a round free-surface water jet on a horizontal air-water interface was experimentally studied. Due to the weakly viscous nature of the flow system under consideration, external perturbations or small variations in jet inflow conditions can lead to drastically different flow field characteristics under seemingly similar test conditions. In the current study, a fully developed turbulent jet, exiting a long pipe, ensured properly characterized inflow conditions. The study considered two jet inflow conditions; one entrained air and created a bubbly two-phase flow field while the other did not. Particle image velocimetry (PIV) was used to characterize the flow field beneath the interface, with and without air entrainment, for various nozzle-to-interface separation distances. Turbulent velocity fields of the continuous-phase and dispersed-phase were simultaneously measured in the developing flow region and presented using Reynolds decomposition into mean and fluctuating components. The mean and RMS velocities of the two-phase flow field were compared with velocity measurements obtained under single-phase conditions.

A CFD Method Study on the Resistance Performance of the Axial Flow Cyclone Separator

2017 ◽  
Author(s):  
Yigang Luan ◽  
Lianfeng Yang ◽  
Tao Sun
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Axial Flow ◽  
Internal Flow ◽  
Operating Pressure ◽  
Cyclone Separator ◽  
Axial Flow Cyclone ◽  
Flow Field Characteristics ◽  
Numerical Simulation Methods ◽  
Resistance Performance

Axial flow cyclone separator with guide blade has been widely used, due to its low resistance, huge gas processing and small volume. Although its structure is simple, three-dimension strong rotating turbulent flow forms which involves many complex interactions such as dual-phase separation, adsorption and electrostatic interference. This paper is focused on studying the resistance performance of the axial flow cyclone separator. Numerical simulation methods are carried out to acquire the internal flow field characteristics under different operating pressure and temperature conditions. The result shows that the pressure drop decreases under the same operating pressure, as the operating temperature increases. When the operating temperature is the same, the higher operating pressure enhances the value of the pressure drop. Velocity distribution, pressure contours and turbulent viscosity contours have been presented, to analyze the characteristics of the internal airflow, so as to help optimize the design. Experiments are intended to verify the results of numerical simulation and explore the internal flow field of the cyclone separator further. The cyclone separator has 8 rotary blades which are split into 8 parts, namely one blade is 45° in the tangential direction. 0° and 22.5° are chosen in the experiment. The dimensionless pressure distribution is shown. A comparison of the CFD results and the experimental results is made to prove that the numerical simulation methods are correct and accurate. The curve of the numerical simulation results is very close to that of the experimental results with the similar trend. It is concluded that the methods can predict the internal flow field characteristics of the axial flow cyclone separator.

The Simulation of the Launching Process on Concentration Water Injection Launcher

2013 ◽  
Vol 419 ◽  
pp. 186-191
Author(s):  
Xiao Fei Zhou ◽  
Yi Jiang ◽  
Yu Sen Niu ◽  
Shao Zhen Yu
Keyword(s):  
Flow Field ◽  
Water Injection ◽  
Calculation Model ◽  
Two Phase ◽  
Average Temperature ◽  
Fluent Software ◽  
Simulation Results ◽  
Temperature And Pressure ◽  
Gas Liquid Flow ◽  
New Research

Simulation of the launching process in concentration water injection launcher, and get the parameter variations during the launch process, compared with traditional engineering algorithm, verify the reliability of the simulation results, given a new research method of interior ballistics on this launch system. This simulation has very important meaning for the temperature and pressure checking at the Beginning of the design. The simulation results show that,after the flow field stable,the average temperature and pressure in low-pressure chamber and the sabot are very close. This article uses the FLUENT software, use Mixture two-phase flow calculation model to solve the gas-liquid flow field, use the dynamic mesh and UDF program to simulation the flow field.

Numerical Optimization of Oilfield Heating Furnace Research

2013 ◽  
Vol 805-806 ◽  
pp. 1874-1877
Author(s):  
Jie Nan Dong ◽  
Xu Su ◽  
Tong Chen ◽  
Miao Wang ◽  
Xiao Xu Li
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Flow Field ◽  
Internal Flow ◽  
Heating Furnace ◽  
Oil Field ◽  
Simulation Tools ◽  
Flow Field Characteristics ◽  
Numerical Simulation Methods ◽  
Physical And Chemical

In this paper,using numerical simulation tools PHOENICS for numerical simulation study is made on furnace gas burning in the hearth, and analyses furnace oil furnace temperature distribution in the flow field characteristics the internal flow field of oil field heating furnace hearth temperature distribution characteristics. On this basis, this paper establisheda mathematical model which can truly describe the chamber internal physical and chemical changes, selected the appropriate numerical simulation methods, plotted the actual temperature profile case, which can reflect the qualitative and quantitative actual situation of work.Finally suggestions are given, which provides the theoretical foundation for the next step and the actual research.

Numerical Simulation on Flow Field of Bladeless Fan

2014 ◽  
Author(s):  
Li Guoqi ◽  
Lin Peifeng ◽  
Cui Baoling ◽  
Jin Yingzi ◽  
Hu Yongjun ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Fluid Motion ◽  
Internal Flow ◽  
External Flow ◽  
Computational Domain ◽  
Static Characteristics ◽  
Whole Process ◽  
Velocity Magnitude ◽  
Flow Field Characteristics

With the advent of bladeless fan, technological revolutions begin to hit the industrial design world of fan. However, there is none of the developed methods on bladeless fan. To explore the excellent blowing performance of bladeless fan, numerical simulation on flow field of bladeless fan was carried out in this paper. Based on the simplified model of bladeless fan, the whole process that the airflow passes through the turbine from the inlet to the outlet slit and exit far field at last, were simulated. By comparing the flux of inlet and the flux of far outlet, the causes of flux increasing are analyzed. After analyzing static characteristics of the flow field, it shows that pressure difference is very obvious. The results obtained from velocity distribution and the characteristics of the pathlines near diffuser section and turbine, were described and analyzed. The results show that the internal flow field characteristics of bladeless fans, which we concern. The external flow field characteristics of bladeless fan was studied in the same way. And it is found that the velocity magnitude of the outlet slit and Coanda surface is much larger than other area and different positions play different roles. A general analysis on inside computational domain and outside computational domain, denotes the details about fluid motion. The research could offer reference to improvement of bladeless fan.

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