scholarly journals Prediction of Horizontal Pneumatic Conveying of Large Coal Particles Using Discrete Phase Model

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Daolong Yang ◽  
Ge Li ◽  
Yanxiang Wang ◽  
Qingkai Wang ◽  
Jianping Li ◽  
...  
Keyword(s):  
Simulation Method ◽  
Phase Model ◽  
Pneumatic Conveying ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Coal Particles ◽  
Large Particles ◽  
Discrete Phase ◽  
Field Velocity ◽  
Conveying System

The pneumatic conveying focusing on gas-solid two-phase flow plays an important role in a conveying system. Previous work has been conducted in the fields of small particles, where the size was less than 5 mm; however, there are few studies regarding large sizes (>5 mm). In order to predict the horizontal pneumatic conveying of large coal particles, the coupling methods based on the Euler–Lagrange approach and discrete phase model (DPM) have been used for the simulated research. Compared with the experimental results under the same working condition, the particle trajectory obtained by simulation is similar to the particle distribution at the same position in the experiment, and it turns out that the simulation method is feasible for the horizontal pneumatic conveying of large particles. Multifactor simulations are also carried out to analyse the effects of particle size, flow field velocity, solid-gas rate, and pipe diameter on the wall abrasion during horizontal pneumatic conveying, which provides simulation reference and design guide for pneumatic conveying of large particles.

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.

A New Ultraprecision Machining Method with Softness Abrasive Flow Based on Discrete Phase Model

2010 ◽  
Vol 97-101 ◽  
pp. 3055-3059 ◽  
Author(s):  
Shi Ming Ji ◽  
Feng Qing Xiao ◽  
Da Peng Tan
Keyword(s):  
Phase Model ◽  
Ultraprecision Machining ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Analog Simulation ◽  
Abrasive Flow Machining ◽  
Irregular Motion ◽  
Discrete Phase ◽  
The Media ◽  
Structural Surface

Considering the demand of precision in mould structural surface polishing method, a new method based on soft abrasive flow machining(SAFM) was proposed, which was supposed to achieve polydirectional and multi-angle cutting acting on the surface of the workpiece by utilizing the irregular motion of both wear particles and the media in turbulence flow. Thus as the monodirectional marks on the machined surfaces was eliminated, the disadvantage in machining precision in conventional abrasive flow machining(AFM) method would be overcome. According to the particle distribution characteristics of SAFM, a two-phase dynamic model of abrasive flow oriented to SAFM combined with Discrete Phase Model(DPM) was built to analog simulation with the software Fluent. Sequently the mechanism of ultraprecision machining towards mould structural surface was analyzed briefly. Simulation results show that the abrasive efficiency along the flow passage can be influenced by the development of turbulence and the distribution of dispersed phase. Thus there a specific region can be obtained in the passage in which the abrasive efficiency is relatively stable.

Concentration Distribution Research of a Special DC Pulverized Coal Burner

2011 ◽  
Author(s):  
Mo Yang ◽  
Chunsun Guo ◽  
Yuwen Zhang ◽  
Zhangyang Kang
Keyword(s):  
Concentration Distribution ◽  
Solid Phase ◽  
Pulverized Coal ◽  
Phase Model ◽  
Discrete Phase Model ◽  
Lagrange Method ◽  
Two Phase ◽  
Discrete Phase ◽  
Special Distribution ◽  
Pulverized Coal Burner

There is a burner which bias block is located in different place compared with other pulverized coal burners. This special DC pulverized coal burner is used to achieve uniform distribution of the export concentration. By numerical method, this article has studied the concentration of this special distribution burner and analyzed internal characteristics. In order to research the effect of bias block in concentration distribution, this special distribution burner has been compared with the structure having no bias block. Euler-Lagrange method and discrete phase model (DPM) are employed to study the gas-solid two phase flow. Solid-phase is simulated in discrete phase model (DPM) and gas-phase in separation vortex (DES).

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.

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