Meso-Structure Parameters of Discrete Element Method of Sand Pebble Surrounding Rock Particles in Different Dense Degrees

2016 ◽  
pp. 871-879 ◽  
Author(s):  
J. F. Lu ◽  
C. W. Zhang ◽  
P. Jian
Keyword(s):  
Discrete Element Method ◽  
Discrete Element ◽  
Surrounding Rock ◽  
Structure Parameters ◽  
Element Method

Computational Fluid Dynamics Flow Simulations in Discrete Element Method-Resolved Packed Beds

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Joanna Zhang ◽  
Babak Shotorban ◽  
Sami Bayyuk ◽  
Sijun Zhang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Discrete Element Method ◽  
Packed Column ◽  
Discrete Element ◽  
Structure Parameters ◽  
Packed Beds ◽  
Computational Results ◽  
Packing Structure ◽  
Element Method

This paper presents computational simulations of flows in packed beds and compares the computational pressure-drop results with those given by the Ergun correlation. The computational methodology used in this work follows the combined discrete element method (DEM) and computational fluid dynamics (CFD) technique. DEM is used to predict the locations and packing structure of the particles in the bed, while CFD is used to predict the flow field in the void space surrounding the packed particles. The computational results obtained for irregular packed beds show that the local packing-structure parameters have significant effects not only on the local velocity and pressure fields but also on macroscopic quantities, such as the average pressure gradient along the length of the packed column. The computational results also show that classical correlations based on averaged values, such as the Ergun correlation, have poor predictive accuracy for macroscopic variations along a packed column, and this is mainly because such correlations do not account for local packing-structure parameters. The computational results confirm the existence of sections with linear variation of macroscopic parameters along the length of the packed column, and this leads to the conclusion that accurate results from DEM-CFD methods on shortened columns can be extrapolated to full-length columns. Moreover, it was found that unlike regularly packed beds, the predicted pressure for randomly packed beds experiences an apparent strong recovery near the downstream end of the packed bed, and then experiences a strong dip down to the plateau leading to the exit pressure.

Simulation Analysis of Seed Metering Procedure in Scoop Metering Device Based on Discrete Element Method

2012 ◽  
Vol 157-158 ◽  
pp. 550-557 ◽  
Author(s):  
Yu Jie Ji ◽  
Hong Da Xue ◽  
Cheng Hua Li
Keyword(s):  
Discrete Element Method ◽  
Simulation Analysis ◽  
Discrete Element ◽  
Design Parameters ◽  
Structure Parameters ◽  
Key Factor ◽  
Seed Metering Device ◽  
Element Method

Seed metering procedure of metering device was a key factor to affect performance of precision seed metering device. Based on analysis of seed holding volume of metering scoop, relationship between the seed holding volume and structure parameters of the metering scoop was established, and beginning and ending angles of seed clearing during the seed metering procedure were determined. Simulation analysis of seed metering procedure with different parameters of the metering device was carried out by mean of discrete element method to identify the influences of metering scoop parameters on the performance the metering device, and suitable range of structure parameters of the metering scoop were investigated. Finally, the reasonability of design parameters of the metering scoop for experiment usage was verified.

Discrete element method to model cracking for two layer systems

TAPPI Journal ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 101-108
Author(s):  
Daniel Varney ◽  
Douglas Bousfield
Keyword(s):  
Discrete Element Method ◽  
Flexural Modulus ◽  
Single Layer ◽  
Discrete Element ◽  
Flexural Stress ◽  
Layer System ◽  
Three Point Bending ◽  
Moving Force ◽  
Coating Layers ◽  
Element Method

Cracking at the fold is a serious issue for many grades of coated paper and coated board. Some recent work has suggested methods to minimize this problem by using two or more coating layers of different properties. A discrete element method (DEM) has been used to model deformation events for single layer coating systems such as in-plain and out-of-plain tension, three-point bending, and a novel moving force picking simulation, but nothing has been reported related to multiple coating layers. In this paper, a DEM model has been expanded to predict the three-point bending response of a two-layer system. The main factors evaluated include the use of different binder systems in each layer and the ratio of the bottom and top layer weights. As in the past, the properties of the binder and the binder concentration are input parameters. The model can predict crack formation that is a function of these two sets of factors. In addition, the model can predict the flexural modulus, the maximum flexural stress, and the strain-at-failure. The predictions are qualitatively compared with experimental results reported in the literature.

Discrete element method–computational fluid dynamics analyses of flexible fibre fluidization

2021 ◽  
Vol 910 ◽  
Author(s):  
Yiyang Jiang ◽  
Yu Guo ◽  
Zhaosheng Yu ◽  
Xia Hua ◽  
Jianzhong Lin ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Discrete Element Method ◽  
Discrete Element ◽  
Dynamics Analyses ◽  
Element Method

Abstract

scholarly journals Numerical simulation on coal loading process of shearer drum based on discrete element method

2021 ◽  
pp. 014459872110135
Author(s):  
Zhen Tian ◽  
Shuangxi Jing ◽  
Lijuan Zhao ◽  
Wei Liu ◽  
Shan Gao
Keyword(s):  
Numerical Simulation ◽  
Discrete Element Method ◽  
Loading Rate ◽  
Low Cost ◽  
Element Model ◽  
Discrete Element ◽  
Helix Angle ◽  
Loading Process ◽  
Coal Particles ◽  
Element Method

The drum is the working mechanism of the coal shearer, and the coal loading performance of the drum is very important for the efficient and safe production of coal mine. In order to study the coal loading performance of the shearer drum, a discrete element model of coupling the drum and coal wall was established by combining the results of the coal property determination and the discrete element method. The movement of coal particles and the mass distribution in different areas were obtained, and the coal particle velocity and coal loading rate were analyzed under the conditions of different helix angles, rotation speeds, traction speeds and cutting depths. The results show that with the increase of helix angle, the coal loading first increases and then decreases; with the increase of cutting depth and traction speed, the coal loading rate decreases; the increase of rotation speed can improve the coal loading performance of drum to a certain extent. The research results show that the discrete element numerical simulation can accurately reflect the coal loading process of the shearer drum, which provides a more convenient, fast and low-cost method for the structural design of shearer drum and the improvement of coal loading performance.

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