scholarly journals Study on Performance of Mesoscopic Impactor Filters for Aerosol Removal

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Wei Zhang ◽  
Fenglei Niu ◽  
Shiji Wang ◽  
Haonan Wang ◽  
Zhangpeng Guo
Keyword(s):  
Collection Efficiency ◽  
Fluid Dynamic ◽  
Structural Parameters ◽  
Continuous Phase ◽  
Discrete Phase Model ◽  
Discrete Phase ◽  
Small Flow ◽  
Cfd Method ◽  
Working Parameters ◽  
Design And Manufacture

The mesoscopic impactor filter is designed to filtrate aerosols in the containment, which has not only high collection efficiency but also small flow resistance. In this paper, the influence of structural parameters and working parameters of the inertial impactor on collection performance is studied by the computational fluid dynamic (CFD) method. Under the small Reynolds number, the laminar model is used to simulate the continuous phase, and the discrete phase model (DPM) is used to track the trajectory of the particle. Based on the response surface methodology (RSM), the prediction model of collection efficiency and pressure drop is obtained, which will provide a reference for the design and manufacture of the filter in the future.

Unsteady Modeling of Powdered Activated Carbon Deposition on Collection Electrode of a Lab-Scale Electrostatic Precipitator (ESP)

2012 ◽  
Author(s):  
Yasmin Khakpour ◽  
Herek L. Clack
Keyword(s):  
Activated Carbon ◽  
Particle Deposition ◽  
Electrostatic Precipitator ◽  
Activated Carbons ◽  
Collection Efficiency ◽  
Continuous Phase ◽  
Powdered Activated Carbon ◽  
Computational Domain ◽  
Discrete Phase Model ◽  
Discrete Phase

Particulate sampling in the flue gas at the Electrostatic Precipitator (ESP) outlet during injection of powdered activated carbons (PACs) has provided strong anecdotal evidence indicating that injected PACs can penetrate the ESP in significant concentrations. The low resistivity of PAC is consistent with poor collection efficiency in an ESP and lab-scale testing has revealed significantly different collection behavior of PAC in an ESP as compared to fly ash. The present study illustrates the use of a commercial CFD package — FLUENT — to investigate precipitation of powdered activated carbon (PAC) in the presence and absence of electric field. The computational domain is designed to represent a 2-D wire-plate ESP channel. The governing equations include those covering continuous phase transport, electric potential, air ionization, and particle charging. The particles are tracked using a Lagrangian Discrete Phase Model (DPM). In addition, a custom user-defined function (UDF) uses a deforming boundary condition and a prescribed critical particle velocity to account for particle deposition and dust-cake growth on the electrodes. The effect of Electrohydrodynamics (EHD) induced flow on the ESP collection efficiency under various flow and particle characteristics as well as different ESP configurations are illustrated.

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.

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.

Numerical Simulation of Steam Generator Tube Rupture Sequence in ADS Reactor

2014 ◽  
Author(s):  
Xu Yang ◽  
Tao Zhou ◽  
Daping Lin ◽  
Xiaolu Fang ◽  
Baixu Chen ◽  
...  
Keyword(s):  
Steam Generator ◽  
Continuous Phase ◽  
Discrete Phase Model ◽  
Primary Coolant ◽  
Steam Generator Tube ◽  
Spallation Target ◽  
Steel Material ◽  
Stainless Steel Material ◽  
Discrete Phase ◽  
Secondary Side

In ADS reactor which choose LBE (Lead-Bismuth Eutectic) as coolant and spallation target. While SGTR (Steam Generator Tube Rupture) accident occur, water in secondary side will inject to LBE in primary coolant, and flow with LBE. The code of FLUENT will be used, steam is looked as particle, and standard k-ε model is used to predict turbulence variation of continuous phase in core. The DPM (Discrete Phase Model) will be used to track the trajectory of the particles. The distribution of steam in core will be obtained, which will verify the safety of reactor. The results show that the steam flowing across the core with LBE, might accumulate in some position and cause a surge of power. At the same time, the aggregation of steam at the channel might lead to a steam plug, and hinder the flow of the coolant in core, then core overheating might occur. Last but not least, local accumulation of water vapor may accelerate the corrosion of stainless steel material in core.

Numerical Simulation of Flow Field in a Quench Oil Tower

2007 ◽  
Author(s):  
Shuihua Zheng ◽  
Shengchang Zhang ◽  
Zengliang Gao
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Flow Field ◽  
Petrochemical Industry ◽  
Flow Distribution ◽  
Discrete Phase Model ◽  
Wide Range ◽  
Modification Method ◽  
Discrete Phase ◽  
Cfd Method

Towers are applied in the wide range of the petrochemical industry. The flow condition and the temperature distribution in the tower are the focus of the people’s attention, which would affect function of the tower and could result in unstable operation of the tower. In this paper, the flow field in a quench oil tower is simulated based on CFD method. The DPM (Discrete Phase Model) is used to calculate and analyze flow distribution and heat transfer between gas and liquid. The numerical results such as temperature and velocity distributions below lower tray in tower are obtained. According to CFD results, modification method of improving the flow distribution is proposed.

A Numerical Study of Turbulence Model and Rebound Model Effect on Erosion Simulations in an Electrical Submersible Pump (ESP)

2019 ◽  
Author(s):  
Haiwen Zhu ◽  
Jun Zhang ◽  
Jianjun Zhu ◽  
Risa Rutter ◽  
Hong-Quan Zhang
Keyword(s):  
Erosion Rate ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Turbulence Models ◽  
Centrifugal Pumps ◽  
Discrete Phase Model ◽  
Ansys Fluent ◽  
Simulation Methodology ◽  
Electrical Submersible Pumps ◽  
Cfd Method

Abstract Sand production is one of the most serious problems of electrical submersible pumps (ESPs). It is important to predict erosion rate and pump life under sand flow condition. However, erosion experiments on centrifugal pumps are difficult, expensive and time-consuming. Besides, the erosion on pump blades and shrouds are hard to be quantified. It is difficult to measure or scan the thickness of an inside flow channel. Therefore, computational fluid dynamic (CFD) method is a convenient way to forecast erosion failures of the pump. Although various erosion simulations were carried out for simple geometries, including pipelines, elbows, tees, and etc., erosion simulation methodology in a turbomachinery geometry should be carefully evaluated. Therefore, the effect of different turbulence models and rebound models are investigated in a 3-stage mixed type ESP by ANSYS Fluent Discrete Phase Model (DPM) simulations. The erosion rate is calculated and particle impact parameters are extracted by a User Define Function (UDF). Preliminary erosion simulation methodology recommendations were given in this study.

scholarly journals Numerical Simulation of Haze-Fog Particle Dispersion in the Typical Urban Community by Using Discrete Phase Model

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 381
Author(s):  
Hongbo Zhu ◽  
Jie Su ◽  
Xuesen Wei ◽  
Zhaolong Han ◽  
Dai Zhou ◽  
...  
Keyword(s):  
Flow Distribution ◽  
Spatial Arrangement ◽  
Particle Dispersion ◽  
Phase Model ◽  
Wind Flow ◽  
Detached Eddy Simulation ◽  
Discrete Phase Model ◽  
Delayed Detached Eddy Simulation ◽  
Discrete Phase ◽  
Cfd Method

The haze-fog particle dispersion in urban communities will cause serious health and environmental problems, which has aroused society attention. The aim of the present investigation is to reveal the underlying mechanisms of haze-fog particle dispersion via Computational Fluid Dynamics (CFD) method, and then to provide a groundwork for the optimal spatial arrangement of urban architecture. The Delayed Detached-eddy Simulation turbulence model (DDES) and Discrete Phase Model (DPM) are utilized to investigate the wind flow distribution and the particle dispersion around the building group. The numerical results show that the particle dispersion is dominated by the incoming wind flow, the layout of architectural space and the type and distribution of vortex. The ‘single body’ wake pattern and the vortex impingement wake pattern are identified in the wind flow field, which have different effects on the distribution of haze-fog particle. The cavity formed by the layout of the building group induces primary vortex and secondary vortex, which will make it more difficult for the particles entering the square cavity to flow out. Moreover, the concentration of the particle in the rear of the buildings is relatively low due the effect of attached vortices.

Aerodynamic Characteristics of NACA 23015 Landing Configuration with 20o Flap in Simulated Rain

2014 ◽  
Vol 555 ◽  
pp. 108-112
Author(s):  
Shahid Latif ◽  
Zhou Hong ◽  
Muhammad Ismail
Keyword(s):  
Heavy Rain ◽  
Aerodynamic Characteristics ◽  
Continuous Phase ◽  
Phase Flow ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Discrete Phase Modeling ◽  
Wall Film ◽  
Discrete Phase ◽  
Simulated Rain

In our numerical simulation the heavy rain effects have been studied on the aerodynamic performance of 2D cambered NACA 23015 airfoil landing configuration with 20o. We have used preprocessing software gridgen for creation of the landing configuration of the airfoil and then creating mesh around it. Fluent is used to solve the conservation equations. We have used discrete phase modeling (DPM) in Fluent to simulate the rain phenomenon in continuous phase flow by using two phase flow approach. In our study the coupling between the discrete and the continuous phase has been activated. In discrete phase model (DPM), we used the wall film model for the interaction of the continuous and discrete phase. The airfoil landing configuration exhibited significant decrease in lift and increase in drag for a given lift conditions in simulated rain. Post processing software like MATLAB, Tec plot and Origin are used to see the effects of the heavy rain and then results obtained are compared with the experimental results. Our numerical results in most of cases show similar trends with the experiments.

scholarly journals Computational Fluid Dynamic study on the effect of near gravity material on dense medium cyclone treating coal using Discrete Phase Model and Algebraic Slip mixture multiphase model

2016 ◽  
Vol 9 (2) ◽  
pp. 58-70 ◽  
Author(s):  
Veera AK Aketi ◽  
TR Vakamalla ◽  
M Narasimha ◽  
GE Sreedhar ◽  
R Shivakumar ◽  
...  
Keyword(s):  
Coal Particle ◽  
Fluid Dynamic ◽  
Phase Model ◽  
Dense Medium ◽  
Multiphase Model ◽  
Discrete Phase Model ◽  
Mixture Density ◽  
Coal Particles ◽  
Discrete Phase ◽  
Dense Medium Cyclone

In this paper, the effect of near gravity material at desired separation density during the coal washing is studied. It is believed that the Dense Medium Separation of coal particles in the presence of high percentage of near gravity material, results in a significant misplacement of coal particles to wrong products. However the performance of dense medium cyclone does not merely depend on the total amount of near gravity materials but also on their distribution as well as on their quality. This paper deals with numerical simulation of magnetite medium segregation and coal partitioning handled in a 350 mm dense medium cyclone. Volume of Fluid coupled with Reynolds Stress Model is used to resolve the two-phase air-core and turbulence. Algebraic Slip mixture multiphase model with the granular options are considered to predict magnetite medium segregation. Medium segregation results are validated against Gamma Ray Tomography measurements. Further, Discrete Phase Model is used to track the coal particles. Residence Time Distribution of different size and density coal particles are also estimated using Discrete Phase Model. Additionally, Algebraic Slip mixture model is also utilised to simulate magnetite and coal particle segregation at different near gravity material proportions. Discrepancies in the coal particle behaviour at different near gravity material content are explained using locus of zero vertical velocities, mixture density, coal volume fractions.

Airfoils Aerodynamic Performance Analysis in Heavy Rain

2012 ◽  
Vol 245 ◽  
pp. 297-302
Author(s):  
Muhammad Ismail ◽  
Yi Hua Cao
Keyword(s):  
Airline Industry ◽  
Heavy Rain ◽  
Quantitative Information ◽  
Aerodynamic Performance ◽  
Small Scale ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Aerodynamic Efficiency ◽  
Discrete Phase ◽  
Cfd Method

Heavy rainfall greatly affects the aerodynamic performance of the aircraft. There are many accidents of aircraft caused by aerodynamic efficiency degradation due to heavy rain. In this paper we have studied the heavy rain effects on the aerodynamic efficiency of NACA 64210 and NACA 0012 airfoils with cruise and landing configuration. For our analysis, CFD method and preprocessing grid generator are used as our main analytical tools, and the simulation of rain is accomplished via two phase flow approach named as Discrete Phase Model (DPM). Raindrops are assumed to be non-interacting, non-deforming, non evaporating and non spinning spheres. Both cruise and landing configurations of airfoils exhibited significant reduction in lift and increase in drag for a given lift condition in simulated rain. Our results are in good agreement with the experimental results. It is expected that the quantitative information gained in this paper will be useful to the operational airline industry and greater effort such as small scale and full scale flight tests should put in this direction to further improve aviation safety.

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