CFD Simulation of Water Flow Mixing With Discrete Phase in a Pump

2013 ◽  
Author(s):  
Mikhail P. Strongin
Keyword(s):  
Particle Distribution ◽  
Cfd Simulation ◽  
Liquid Mixture ◽  
Industrial Applications ◽  
Discrete Phase Model ◽  
Water Transportation ◽  
Flow Mixing ◽  
Discrete Phase ◽  
The Subject ◽  
Pump Inlet

The mixing process is very common in many industrial applications. In some cases, two or more liquids or discrete phase (DP) set on the pump inlet. Liquid mixture is often occurred in sanitation and agriculture applications and mixture of water with DP (such as sand) are met in the case of water transportation from natural sources (rivers, wells, etc.). DP distribution in the centrifugal pump is the subject of this study. Full pump geometry is considered, due to unsymmetrical nature of volute of the pump. Turbulence k-ε closure model and Lagrangian discrete phase model has been used for most simulations. It was found that smaller particles trap inside the pump for longer time than larger ones. The distribution of the bigger diameter particles on the outlet is more asymmetrical in comparison with particles of smaller diameter. Relatively large areas with very small particle concentrations can be observed. Particle distribution on the outlet for lighter particles demonstrates more uniformity.

CFD Study on must of Grapes Separation in a Hydrocyclone

2013 ◽  
Vol 837 ◽  
pp. 645-650
Author(s):  
Petru Cârlescu ◽  
Ioan Tenu ◽  
Marius Baetu ◽  
Radu Rosca
Keyword(s):  
Cfd Simulation ◽  
Reynolds Stress Model ◽  
Continuous Phase ◽  
Solid Particles ◽  
Advanced Degree ◽  
Separation And Purification ◽  
Discrete Phase Model ◽  
Flow Rates ◽  
Discrete Phase ◽  
Simulation And Experiment

Abstract. Hydrocyclones are increasingly used in the food industry for various separation and purification. In this paper, an optimization was made to design a hydrocyclone model using CFD (Computational Fluid Dynamics). CFD simulation is performed with FLUENT software by coupling the Reynolds Stress Model (RSM) for must of grapes flow with Discrete Phase Model (DPM) for solid particles trajectory. Coupling of discrete phase (particles) and continuous phase (must of grapes) in the mathematical model is set so that the continuous phase to influence discrete phase. Tracking particles traiectory in this hydrocyclone allows advanced degree is separation so obtained to the maximum particle size approaching the size of a yeast cell 10 μm, without separating them. Hydrocyclone dimensional designed simulation was performed and analyzed on an experimental pilot plant for three different must flow rates supply. Introduced particle flow rates simulation and experiment does not exceed 10% of the must flow rates. The degree of separation obtained is in agreement with experimental data.

CFD Simulation of COVID Aerosol Dispersion in Indoor Environments

2021 ◽  
Author(s):  
Mohammed Abushamleh ◽  
Ning Zhang
Keyword(s):  
Relative Humidity ◽  
Cfd Simulation ◽  
Medium Size ◽  
Indoor Environments ◽  
Discrete Phase Model ◽  
Discrete Phase ◽  
Computational Fluid Dynamics Simulations ◽  
Aerosol Dispersion ◽  
Dynamics Simulations ◽  
Simulation Time

Abstract Computational Fluid Dynamics simulations for the droplet’s dispersion generated by a cough in an indoor background, droplets trajectory, and evaporation time are predicted to be related to the droplet’s diameter and relative humidity. In general, medium-size droplets have higher axial penetration potential, and large droplets tend to settle on the ground due to gravity. Also, larger droplets take a longer time to evaporate. Smaller droplets tend to be suspended in the flow field with small penetration potential and tend to fade faster; smaller droplets < 20 μm evaporate completely before the simulation time reaches 0.75 sec. To study the effect of Relative Humidity (RH) on the evaporation rate, in particular, the present study offers three simulations, all with the same standard room conditions, only differ in relative humidity s 40%, 60%, and 90%. Another source of variability is the cough-expired volume. This study adopts existent experimental work to establish two cough flow rate profiles. The Lagrangian discrete phase model is adopted along with the species model to track and investigate the cough droplet dispersion and evaporation.

Simulation of Airflow and Fuel Spray Through an Axial Swirler for Gas Turbine Applications

2008 ◽  
Author(s):  
Joshua E. Kempenaar ◽  
Kim A. Shollenberger ◽  
Gareth W. Oskam
Keyword(s):  
Gas Turbine ◽  
Cfd Simulation ◽  
Cross Flow ◽  
Fuel Spray ◽  
Fuel Injector ◽  
Discrete Phase Model ◽  
Flow Area ◽  
Jet In Cross Flow ◽  
Discrete Phase ◽  
Break Up

A computational fluid dynamics (CFD) simulation of the effects of an upstream blockage on the fuel spray and airflow through an axial swirler in an experimental gas turbine fuel injector has been conducted. Blockage was varied by means of varying the inside diameter of a restriction upstream of the entrance to the axial swirler. Fuel is injected as a jet in cross-flow through fuel nozzles located in axial swirler vanes. Fuel spray was modeled in the commercial CFD code Fluent 6.3.26 using the Lagrangian approach with the built-in Discrete Phase Model (DPM). Results are given for the TAB, Wave, and KH-RT break-up models. Preliminary simulations with the TAB break-up model were performed for a simple axisymmetric jet and compared to experimental results before simulating the axial swirler geometry. The axial swirler simulations predict that spray dispersion decreases and droplet size increases as the flow area of the blocker ring increases.

scholarly journals Performance Characterization of the UAV Chemical Application Based on CFD Simulation

Agronomy ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 308 ◽  
Author(s):  
Hang Zhu ◽  
Hongze Li ◽  
Cui Zhang ◽  
Junxing Li ◽  
Huihui Zhang
Keyword(s):  
Wind Speed ◽  
Correlation Coefficient ◽  
Cfd Simulation ◽  
Least Square Method ◽  
Least Square ◽  
Universal Method ◽  
Discrete Phase Model ◽  
Chemical Application ◽  
Distance Model ◽  
Discrete Phase

Battery-powered multi-rotor UAVs (Unmanned Aerial Vehicles) have been employed as chemical applicators in agriculture for small fields in China. Major challenges in spraying include reducing the influence of environmental factors and appropriate chemical use. Therefore, the objective of this research was to obtain the law of droplet drift and deposition by CFD (Computational Fluid Dynamics), a universal method to solve the fluid problem using a discretization mathematical method. DPM (Discrete Phase Model) was taken to simulate the motion of droplet particles since it is an appropriate way to simulate discrete phase in flow field and can track particle trajectory. The figure of deposition concentration and trace of droplet drift was obtained by controlling the variables of wind speed, pressure, and spray height. The droplet drifting models influenced by different factors were established by least square method after analysis of drift quantity to get the equation of drift quantity and safe distance. The relationship model, Yi(m), between three dependent variables, wind speed Xw(m s−1), pressure Xp(MPa) and spray height Xh(m), are listed as follows: The edge drift distance model was Y1 = 0.887Xw + 0.550Xp + 1.552Xh − 3.906 and the correlation coefficient (R2) was 0.837; the center drift distance model was Y2 = 0.167Xw + 0.085Xp + 0.308Xh − 0.667 and the correlation coefficient (R2) was 0.774; the overlap width model was Y3 = 0.692xw + 0.529xp + 1.469xh − 3.374 and the correlation coefficient (R2) was 0.795. For the three models, the coefficients of the three variables were all positive, indicating that the three factors were all positively correlated with edge drift distance, center drift distance, and overlap width. The results of this study can provide theoretical support for improving the spray quality of UAV and reducing the drift of droplets.

Air Assisted Atomization Characterization of Biodegradable Fluid Using Microlubrication Technique

2021 ◽  
Vol 1019 ◽  
pp. 211-217
Author(s):  
Dipali K. Bhise ◽  
Bhushan T. Patil ◽  
Vasim A. Shaikh
Keyword(s):  
Droplet Size ◽  
Flow Rate ◽  
Castor Oil ◽  
Industrial Applications ◽  
Phase Model ◽  
Discrete Phase Model ◽  
Performance Study ◽  
Spray Formation ◽  
Discrete Phase ◽  
Atomization Characteristics

In microlubrication, effective spray cooling is generally dependent on the atomization process. Air assisted atomizer is commonly used in many industrial applications because even at low-pressure fuel or coolant supply, it can create a fine spray formation. Viscosity force resists the deformation of liquid ligaments into a droplet. This increase in viscosity creates a bigger droplet size. If the density of the coolant is more, it will resist the acceleration and results in a bigger droplet. Properties of coolant such as viscosity, density, and surface tension are important and will affect the droplet size. Hence, for effective microlubrication, the performance study of atomization is important. In this paper, computational fluid dynamics (CFD) is used to study atomization characteristics of biodegradable coolant castor oil and AccuLube-2000 at flow rate 150 ml/hr to 60 ml/hr. This paper focuses on the effect of coolant properties like viscosity and density on the droplet size and discrete phase model concentration. In this work, the CFD atomization is studied using a discrete phase model and a Realizable k-ϵ turbulent flow model. Numerical simulation shows that the droplet size of the castor oil is more than AccuLube-2000. Also, for a higher flow rate, the area near the nozzle had a very uneven concentration of sprayed particles. However, the concentration was more even as the spray went farther away from the nozzle.

scholarly journals Simulation of un industrial waste treatment tank

2020 ◽  
Vol 9 (4) ◽  
pp. e180942542
Author(s):  
Elcio Fernando Pereira ◽  
Luiz Mário Nelson Gois
Keyword(s):  
Petrochemical Industry ◽  
Cfd Simulation ◽  
Waste Treatment ◽  
Discrete Phase Model ◽  
Depth Data ◽  
Treatment Tank ◽  
Computational Mesh ◽  
Discrete Phase ◽  
Particles Trajectories ◽  
Lagrange Approach

The objective of the present work was to evaluate the operation of an industrial sedimentation tank used in the separation of solid waste from the petrochemical industry. The depth data were obtained through a “interface float”, while the diameters and the positions of the particles through the CFD simulation. The computational fluid dynamics simulator (FLUENT 6.3.26) was used to perform a multiphase simulation using the Euler-Lagrange approach and was used to determine the particles trajectories and cotours of solids accumulated in the bottom of the tank. This allowed a better understanding of solids accumulation and improvement of the cleaning process. In the simulation of the tank a large computational mesh comprising 464,094 computational nodes was designed. The use of the Euler-Lagrange approach meant that a discrete phase model had to be established and the parameters of Rosin-Rammler solids distribtion model for the boundary conditions of the simulation had to be determined. 

CFD Simulation and Performance Analysis of CJD Burner for Intensified Flash Smelting Process

2012 ◽  
Author(s):  
Zhuo Chen ◽  
Peng Long ◽  
Zhiqiang Sun ◽  
Jun Zhou ◽  
Jiemin Zhou
Keyword(s):  
Cfd Simulation ◽  
Flash Smelting ◽  
Smelting Process ◽  
Flash Furnace ◽  
Discrete Phase Model ◽  
Reaction Shaft ◽  
Technical Problems ◽  
Dust Generation ◽  
Discrete Phase ◽  
And Performance

The flash smelting process has been widely acknowledged as a successful modern pyro-metallurgical technology because of its good production flexibility. In past decades, great efforts have been put on the equipment improvement in order to achieve a highly intensive and efficient flash smelting process. However, along with the increasing of the productivity and the intensification of the process, technical problems such as the un-smelted materials accumulated in the settler and the dust generation ratio going higher are found occurring more frequently than before. All these problems however indicate degeneration in the performance of the central jet distributor (CJD) burner. A study was then made on the combustion and reaction processes in the flash furnace equipped with a CJD burner. A steady-state turbulent model was developed and a discrete phase model was included to investigate the velocity and temperature changes of both the gaseous and particle phases in the reaction shaft. The deviation of the numerical model is estimated to be less than 6%. The simulation results reveal a serious delay in the ignition of concentrate particles after they are fed into the furnace. Minor modification was also made by CFD computation, attempting to improve the particle ignition speed, but it was found not so effective. The main reason for the decreased smelting efficiency is found to be the poor mixing between the gaseous and particle phases under the intensified condition. These appeal for a great improvement in the performance of the CJD burner.

scholarly journals Effects of Blade Parameters on the Flow Field and Classification Performance of the Vertical Roller Mill via Numerical Investigations

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Chang Liu ◽  
Zuobing Chen ◽  
Weili Zhang ◽  
Chenggang Yang ◽  
Ya Mao ◽  
...  
Keyword(s):  
Flow Field ◽  
Pressure Difference ◽  
Continuous Phase ◽  
Classification Performance ◽  
Field Analysis ◽  
Discrete Phase Model ◽  
Roller Mill ◽  
Discrete Phase ◽  
Vertical Roller ◽  
Classification Efficiency

The vertical roller mill is an important crushing and grading screening device widely used in many industries. Its classification efficiency and the pressure difference determine the entire producing capacity and power consumption, respectively, which makes them the two key indicators describing the mill performance. Based on the DPM (Discrete Phase Model) and continuous phase coupling model, the flow field characteristics in the vertical roller mill including the velocity and pressure fields and the discrete phase distributions had been analyzed. The influence of blade parameters like the shape, number, and rotating speed on the flow field and classification performance had also been comprehensively explored. The numerical simulations showed that there are vortices in many zones in the mill and the blades are of great significance to the mill performance. The blade IV not only results in high classification efficiency but also reduces effectively the pressure difference in the separator and also the whole machine. The conclusions of the flow field analysis and the blade effects on the classification efficiency and the pressure difference could guide designing and optimizing the equipment structure and the milling process, which is of great importance to obtain better overall performance of the vertical roller mill.

scholarly journals Enhanced discrete phase model for multiphase flow simulation of blood flow with high shear stress

2021 ◽  
Vol 104 (1) ◽  
pp. 003685042110080
Author(s):  
Zheqin Yu ◽  
Jianping Tan ◽  
Shuai Wang
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Multiphase Flow ◽  
Experimental Verification ◽  
Flow Simulation ◽  
Turbulence Models ◽  
Phase Model ◽  
Force Model ◽  
Discrete Phase Model ◽  
Discrete Phase

Shear stress is often present in the blood flow within blood-contacting devices, which is the leading cause of hemolysis. However, the simulation method for blood flow with shear stress is still not perfect, especially the multiphase flow model and experimental verification. In this regard, this study proposes an enhanced discrete phase model for multiphase flow simulation of blood flow with shear stress. This simulation is based on the discrete phase model (DPM). According to the multiphase flow characteristics of blood, a virtual mass force model and a pressure gradient influence model are added to the calculation of cell particle motion. In the experimental verification, nozzle models were designed to simulate the flow with shear stress, varying the degree of shear stress through different nozzle sizes. The microscopic flow was measured by the Particle Image Velocimetry (PIV) experimental method. The comparison of the turbulence models and the verification of the simulation accuracy were carried out based on the experimental results. The result demonstrates that the simulation effect of the SST k- ω model is better than other standard turbulence models. Accuracy analysis proves that the simulation results are accurate and can capture the movement of cell-level particles in the flow with shear stress. The results of the research are conducive to obtaining accurate and comprehensive analysis results in the equipment development phase.

Effect of position of the fiber transport channel on fiber motion in the high-speed rotor

2021 ◽  
pp. 004051752110018
Author(s):  
Rui Hua Yang ◽  
Chuang He ◽  
Bo Pan ◽  
Hongxiu Zhong ◽  
Cundong Xu
Keyword(s):  
High Speed ◽  
Channel Model ◽  
Three Dimensional ◽  
Discrete Phase Model ◽  
Transport Channel ◽  
Rotor Spinning ◽  
Fiber Motion ◽  
Discrete Phase ◽  
Airflow Field ◽  
Fiber Transport

The task of the fiber transport channel (FTC) is to transport the fibers from the carding roller to the rotor. Its geometric position in the spinning machine has a strong influence on the characteristics of the airflow field and the trajectory of the fiber motion in both the rotor and the FTC. In this paper, a three-dimensional pumping rotor spinning channel model was established using ANSYS-ICEM-CFD software with three different positions of the FTC (positions a–c). Further, the simulations of air distribution were performed using Fluent software. In addition, the discrete phase model was used to fit the fiber motion trajectory in the rotor. The simulation results showed that among the three types of FTC, position b is the optimal condition. The gradients of airflow velocity in the channel at position b were greater than those of the other two positions, which is conducive to straightening of the fiber.

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