scholarly journals Analysis of the Effect of Ventilation Bars on the Packing Structure of Sinter Bed by DEM Simulation

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3836
Author(s):  
Shingo Ishihara ◽  
Kizuku Kushimoto ◽  
Junya Kano
Keyword(s):  
Shear Flow ◽  
Discrete Element Method ◽  
Adhesion Force ◽  
Sinter Machine ◽  
Discrete Element ◽  
Angle Of Repose ◽  
Dem Simulation ◽  
Packing Structure ◽  
Experimental Values ◽  
Simulation Parameters

The effect of ventilation bars on the porosity of a sinter bed charged on a sinter machine was investigated. The behavior of the sinter feed was calculated by discrete element method (DEM) simulation. By taking into account the adhesion force, the sinter feed in the wet state was represented and the simulation parameters were determined to reproduce the experimental values of the angle of repose. The porosity of the sinter bed was calculated, and the mechanism of the formation of the packing structure and the cause of the distribution of porosity in each region were clarified. As a result, it is shown that in the case of shear flow, the higher the powder pressure during flow, the higher the porosity.

scholarly journals Calibration and Tests for the Discrete Element Simulation Parameters of Fallen Jujube Fruit

Agriculture ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 38
Author(s):  
Gaokun Shi ◽  
Jingbin Li ◽  
Longpeng Ding ◽  
Zhiyuan Zhang ◽  
Huizhe Ding ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Simulation Model ◽  
Static Friction ◽  
Discrete Element ◽  
Angle Of Repose ◽  
Average Error ◽  
Dem Simulation ◽  
Static Friction Coefficient ◽  
Jujube Fruit ◽  
Simulation Parameters

Discrete element method (DEM) simulation is an important method to analyze the interaction relationship between materials and equipment, and to develop machinery and/or equipment. However, it is necessary to input specific simulation parameters when establishing a DEM simulation model. In this study, the interval values were measured through angle of repose tests of fallen jujube fruit (FJF), and the simulation angle of repose tests for FJF were established with EDEM software (DEM Solutions Ltd. Edinburgh, Scotland, UK). Then, the Plackett-Burman design, steepest ascent search experiment, and center composite design experimental methods were utilized to obtain the specific values of the simulation parameters from the interval values. The results showed that significant influencing factors in the simulation angle of repose include the Poisson’s ratio, the static friction coefficient between FJF, and the static friction coefficient between FJF and the steel plate, for which the optimal values were 0.248, 0.480, and 0.309, respectively. The angle of repose tests’ results showed that the error was 0.53% between the simulation angle of repose (29.69°) and the angle of repose (29.85°). In addition, the flow rate test results showed that the average error was 5.84% between the physical and simulation tests. This indicated that the calibrated parameters were accurate and reliable, and that the simulation model can accurately represent the physical tests. Consequently, this study provides an EDEM model of FJF that was essential in designing machinery and equipment through the EDEM simulation method.

scholarly journals Measurement and Calibration of the Parameters for Discrete Element Method Modeling of Rapeseed

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 605
Author(s):  
Xiulong Cao ◽  
Zehua Li ◽  
Hongwei Li ◽  
Xicheng Wang ◽  
Xu Ma
Keyword(s):  
Discrete Element Method ◽  
Static Friction ◽  
Discrete Element ◽  
Rolling Friction ◽  
Particulate Material ◽  
Angle Of Repose ◽  
Model Parameters ◽  
Dem Simulation ◽  
Response Surface Optimization ◽  
Element Method

The discrete element method (DEM) for modeling the behavior of particulate material is highly dependent on the use of appropriate and accurate parameters. In this study, a seed metering DEM simulation was used to measure, calibrate, and verify the physical and interactional parameters of rapeseed. The coefficients of restitution and static friction between rapeseeds and three common materials (aluminum alloy, acrylic, and high-density polyethylene) were measured using free drop and sliding ramp tests, respectively. The angle of repose was determined using a hollow cylinder experiment, which was duplicated using a DEM simulation, to examine the effects of static and rolling friction coefficients on the angle of repose. Response surface optimization was performed to determine the optimized model parameters using a Box–Behnken design test. A metering device was made with three materials, and rapeseed seeding was simulated at different working speeds to verify the calibrated parameters. The validation results showed that the relative errors between the seed metering model and experiments for the single qualified seeding, missed seeding, and multiple seeding rates were −0.15%, 3.29%, and 5.37%, respectively. The results suggest that the determined physical and interactional parameters of rapeseed can be used as references for future DEM simulations.

scholarly journals Analysis of Inter-particle Contact Parameters of Garlic Cloves Using Discrete Element Method

2021 ◽  
Author(s):  
Donghyeok Park ◽  
Chun Gu Lee ◽  
Doee Yang ◽  
Daehyun Kim ◽  
Joon Yong Kim ◽  
...  
Keyword(s):  
Discrete Element Method ◽  
Discrete Element ◽  
Prediction Equation ◽  
Angle Of Repose ◽  
Particle Model ◽  
Bulk Properties ◽  
Simulation Results ◽  
Contact Parameters ◽  
Number Of Particles ◽  
Residual Number

Abstract Purpose The discrete element method (DEM) can be used in agricultural fields such as crop sowing, harvesting, and crop transportation. Nevertheless, modeling complex crops as appropriately shaped particles remains challenging. The modeling of particles and the calibration of input parameters are important for simulating the realistic behaviors of particles using the DEM. Methods In this study, particle models representing the morphological characteristics and size deviations of garlic cloves were proposed. Additionally, the coefficients of friction were analyzed as the contact parameters of the particles based on the heap formation experiments and simultations of the swing-arm method using 150 garlic cloves. Results The simulation results were analyzed that the residual number of particles, a bulk property that can be measured simply in the experiment, is related to the coefficients of friction. In the heap formation experiments with low particle counts, the bulk properties were more clearly differentiated by the residual number of particles than the angle of repose. Moreover, the bulk properties similar to the actual garlic could not be expressed as a spherical particle model. Thus, an equation for predicting the residual number of particles was derived for the non-spherical garlic clove particle model. Five sets of coefficients of friction were presented using the prediction equation, and all the simulation results were close to the actual residual number of particles and angle of repose of the garlic. Conclusions Although the sizes of garlic cloves have a wide distribution, appropriate inter-particle contact parameters could be predicted. Therefore, the calibration process of the DEM can be shortened using the proposed prediction equation for the residual number of particles with non-spherical particles.

Combined CFD and DEM Simulations of Fluid Flow and Heat Transfer in a Pebble Bed Reactor

2011 ◽  
Author(s):  
Xiang Zhao ◽  
Trent Montgomery ◽  
Sijun Zhang
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Discrete Element Method ◽  
Reactor Core ◽  
Turbulence Models ◽  
Discrete Element ◽  
Pebble Bed ◽  
Pebble Bed Reactor ◽  
Packing Structure ◽  
Dem Simulations

This paper presents combined computational fluid dynamics (CFD) and discrete element method (DEM) simulations of fluid flow and relevant heat transfer in the pebble bed reactor core. In the pebble bed reactor core, the coolant passes highly complicated flow channels, which are formed by thousands of pebbles in a random way. The random packing structure of pebbles is crucial to CFD simulations results. The realistic packing structure in an entire pebble bed reactor (PBR) is generated by discrete element method (DEM). While in CFD calculations, selection of the turbulence models have great importance in accuracy and capturing the details of the flow features, in our numerical simulations both large eddy simulation (LES) and Reynolds-averaged Navier-Stokes (RANS) models are employed to investigate the effects of different turbulence models on gas flow field and relevant heat transfer. The calculations indicate the complex flow structure within the voids between the pebbles.

scholarly journals DEM simulation research of selected sowing unit elements used in a mechanical seeding drill

2019 ◽  
Vol 254 ◽  
pp. 02021
Author(s):  
Jacek Marcinkiewicz ◽  
Jarosław Selech ◽  
Żaneta Staszak ◽  
Łukasz Gierz ◽  
Dariusz Ulbrich ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Discrete Element Method ◽  
Mathematical Models ◽  
Discrete Element ◽  
Simulation Research ◽  
Dem Simulation ◽  
Bench Tests ◽  
Modern Computer ◽  
Design Solutions ◽  
Simulation Systems

The paper presents the results of research aimed at the verification of the existing design solutions of four example sowing units for agricultural seed drills with the most frequently used types of sowing wheels. The research was conducted with the use of modern computer simulation systems based on the discrete element method (DEM) with the evaluation of the efficiency of selected design solutions in terms of achieved performance and metering uniformity. The paper includes a description of virtual research models and the employed mathematical models used for mirroring contact between seeds. Moreover, for the purpose of verification of the obtained results, bench tests were conducted using actual models of selected design solutions.

scholarly journals A Numerical Study of Railway Ballast Subjected to Direct Shearing Using the Discrete Element Method

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Hongyi Zhao ◽  
Jing Chen
Keyword(s):  
Discrete Element Method ◽  
Mechanical Performance ◽  
Numerical Study ◽  
Discrete Element ◽  
Contact Forces ◽  
Angle Of Repose ◽  
Particle Rotation ◽  
Railway Ballast ◽  
Depth Analysis ◽  
Element Method

Railway ballast is a coarse granular material used to carry train loads and provide drainage for the rail tracks. This study presents numerical explorations of the mechanical performance of ballast aggregates subjected to direct shear tests. The discrete element method (DEM) was used to investigate the microscopic characteristics of ballast aggregates during shearing while considering contact distribution, particle rotation, and particle displacement. By testing the angle of repose of ballast aggregates, the parameters for the DEM contact model could be calibrated. Four specimens were prepared and then subjected to different normal pressures. The results show that the contact between ballast particles intensifies in terms of the amount and magnitude as the normal pressure increases. A Fourier analysis was applied to investigate the anisotropy of contact normal and the contact forces for ballast aggregates at different shearing phases. The rotational and translational movements of ballast particles were investigated, and this investigation revealed that particle rotation gradually increased as the shearing propagated. Four regions in the aggregates were identified according to the translational pattern of ballast particles. The results of this research provide an in-depth analysis of microscopic characteristics from a particulate scale.

scholarly journals Coarse-grained discrete element method for granular shear flow

2020 ◽  
Vol 4 ◽  
pp. 100050
Author(s):  
Hideya Nakamura ◽  
Hiroharu Takimoto ◽  
Naoki Kishida ◽  
Shuji Ohsaki ◽  
Satoru Watano
Keyword(s):  
Shear Flow ◽  
Discrete Element Method ◽  
Discrete Element ◽  
Coarse Grained ◽  
Granular Shear ◽  
Element Method

scholarly journals Exploring the End-Liner Forces Using DEM Software

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1047
Author(s):  
Ngonidzashe Chimwani ◽  
Murray M. Bwalya
Keyword(s):  
Discrete Element Method ◽  
Size Distribution ◽  
Ball Milling ◽  
Discrete Element ◽  
Significant Cost ◽  
Cost Component ◽  
Dem Simulation ◽  
Ball Size ◽  
Ball Motion ◽  
Simulation Scheme

The main roles of liners are to protect the mill shell and promote effective ball motion for grinding. For this reason the liner profile is carefully selected to ensure that the productivity is maximized and due liner replacement is made when this objective is no longer met. These issues have been extensively studied on shell liners as mill relining is a significant cost component of ball milling. To date, not much has been written about end-liners and the kind of forces they are subjected to. A discrete element method (DEM) simulation scheme is conducted to look at how ball size distribution, mill filling, end-liner configuration and shape affect the distribution of forces acting on the liners that were assessed to understand end-liner wear and damage. The results showed how forces varied both radially and tangentially for the different sections of end-liner, with important insights drawn for end-liner manufactures.

DEM simulation of the local ordering of tetrahedral granular matter

Soft Matter ◽  
2019 ◽  
Vol 15 (10) ◽  
pp. 2260-2268 ◽  
Author(s):  
Bo Zhao ◽  
Xizhong An ◽  
Haiyang Zhao ◽  
Lingling Shen ◽  
Xudong Sun ◽  
...  
Keyword(s):  
Discrete Element Method ◽  
Dynamic Simulation ◽  
Granular Matter ◽  
Discrete Element ◽  
Local Order ◽  
Sphere Model ◽  
Mechanical Vibrations ◽  
Dem Simulation ◽  
Granular Assembly ◽  
Local Ordering

The formation and growth of local order clusters in a tetrahedral granular assembly driven by 3D mechanical vibrations were captured in DEM (discrete element method) dynamic simulation using a multi-sphere model.

Jaw Crusher Based on Discrete Element Method

2013 ◽  
Vol 312 ◽  
pp. 101-105
Author(s):  
Fu Sheng Mu ◽  
Hui Li ◽  
Xing Xue Li ◽  
Hong Zhi Xiong
Keyword(s):  
Energy Consumption ◽  
Discrete Element Method ◽  
Discrete Element ◽  
Working Process ◽  
Element Analysis ◽  
Dem Simulation ◽  
Force Condition ◽  
Jaw Crusher ◽  
Set Up ◽  
Element Method

In order to analyze the force condition and crushing power of crusher teeth plate, the discrete element method models of jaw crusher and double-cavity jaw crusher are set up respectively using EDEM, a kind of software for discrete element analysis. Meanwhile, the working process, the loading force on the teeth plate and crushing power are simulated. The results show that: the rationality of the DEM simulation is declared, and the crushing process of the particles is also shown intuitively. The loading force condition and the crushing power of the moving jaw teeth plate serve as basis for its abrasion and energy consumption respectively.

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