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The purpose of this paper is to examine several calibration techniques that have been developed to determine the discrete element method (DEM) parameters for slow and rapid unconfined flow of granular conical pile formation. This paper also aims to discuss some of the methods currently employed to scale particle properties to reduce computational resources and time to solve large DEM models.

DEM models have been calibrated against simple bench‐scale experimental results to examine the validity of selected parameters for the contact, material and mechanical models to simulate the dynamic and static behaviour of cohesionless polyethylene pellets. Methods to determine quantifiable single particle parameters such as static friction and the coefficient of restitution have been highlighted. Numerical and experimental granular pile formation has been investigated using different slumping and pouring techniques to examine the dependency of the type of flow mechanism on the DEM parameters.

The proposed methods can provide cost effective and simple techniques to determine suitable input parameters for DEM models. Rolling friction and particle shape representation has shown to have a significant influence on the bulk flow characteristics via a sensitivity analysis and needs to be accessed based on the environmental conditions.

This paper describes several effective known and novel methodologies to characterise granular materials that are needed to accurately model granular flow using the DEM to provide valuable quantitative data. For the DEM to be a viable predictive tool in industrial applications which often contain huge quantities of particles with random particle shapes and irregular properties, quick and validated techniques to “tune” DEM models are necessary.

Application of the discrete element method (DEM) to real scale engineering problems involving three‐dimensional modelling of large, non‐spherical particles must consider the inertia tensor and temporal change in the orientation of the particles when calculating the rotational motion. This factor has commonly been neglected in discrete element modelling although it will significantly influence the dynamic behaviour of non‐spherical particles. In this paper two methods, vector transformation and tensor transformation, for calculation of the rotational motion of particles in response to applied moments are presented. The methods consider the inertia tensor and the local object frame of arbitrary shaped particles and suggest solutions for the non‐linear Euler equations for calculation of their rotational motion. They are discussed with respect to implementation into a discrete element code and assessed in terms of their accuracy and computational efficiency.

A new method of representing non‐spherical, smooth‐surfaced, axi‐symmetrical particles in discrete element (DE) simulation using model particles comprising overlapping spheres of arbitrary size whose centres are fixed in position relative to each other along the major axis of symmetry of the particle is presented. Contact detection and calculation of force‐deformation and particle movement is achieved using standard DE techniques modified to integrate the behaviour of each element sphere with that of the multi‐element particle to which it belongs. The method enables the dynamic behaviour of particles of high aspect ratio and irregular curvature (in two dimensions) to be modelled. The use of spheres to represent a particle takes advantage of the computational speed and accuracy of contact detection for spheres, which should make the method comparable in computational efficiency to alternative schemes for representing non‐spherical particles.

The purpose of this paper is to fundamentally develop a mathematical model for predicting the particle size distribution (PSD) in fluidized beds because their hydrodynamics depend on the PSD and its evolution during operation. To predict the gradual PSD change in a fluidized bed by using the population balance method (PBM), the kinetic parameter for agglomerate formation should be known and this parameter, in this work, is determined by the results of computational fluid dynamic–discrete element method (CFD-DEM) simulation.

Momentum and energy conservation equations and soft-sphere DEM are used to simulate the agglomeration phenomenon at high temperature in a two-dimensional air-polyethylene fluidized bed in bubbling regime. The Navier–Stokes equations for motion of gas are solved by the SIMPLE algorithm. Newton’s second law of motion is applied to describe the motion of individual particles. Collision between particles is detected by the no-binary search algorithm.

A correlation is proposed for estimating the kinetic parameter for agglomerate formation based on collision frequency, collision efficiency and inlet gas temperature. Based on the corrected kinetic parameter, the PBM is able to predict the PSD evolution in the fluidized bed in a fairly good agreement with the results of the CFD-DEM.

The results of the agglomeration process cannot be compared quantitatively with experimental results. Because three-dimensional fluidized bed mostly contains millions of particles and simulating them takes a long computing time in DEM. As far as temperature is a dominant parameter in the agglomeration process, effects of inlet gas temperature are examined on the kinetic parameter. On the other hand, wider and deeper insights in which the effect of other parameters, such as velocity and so on will be studied, is one of the goals in the authors’ next works to compensate for the shortcomings in this work.

This study helps to understand the effect of the inlet gas temperature during the agglomeration process on the kinetic parameter and provides fundamental information in dealing with kinetic parameter to attain PSD in fluidized bed by the PBM.

The particle damper is an efficient vibration control device and is widely used in engineering projects; however, the performance of such a system is very complicated and highly nonlinear. The purpose of this paper is to accurately simulate the particle damper system properly, and help to understand the underlying physical mechanics.

A high-fidelity simulation process is well established to account for all significant interactions among the particles and with the host structure system, including sliding friction, gravitational forces, and oblique impacts, based on the modified discrete element method. In this process, a suitable particle damper system is modeled, reaction forces between particle aggregates and the primary structure are incorporated, a reasonable contact force model and time step are determined, and an efficient contact detection algorithm is adopted.

The numerical results are further validated by both special computational tests and shaking table tests, with good agreements to the experimental results. The method is shown to be effective and accurate to simulate the particle damper system.

The approaches described in this paper provide an efficient numerical way to investigate complex particle damper systems.

The purpose of this study is to explore how particle shape influences the screening, including screening efficiency per unit time, and the relationship between vibration parameters and screening efficiency per unit time in discrete element method (DEM) numerical simulations.

In this paper, a three-dimensional discrete element model of vibrating screen with composite vibration form of swing and translation was proposed to simulate the screening process. In total, 11 kinds of non-spherical particles whose shapes changed in a continuous regularity gradual process were established using a multi-sphere method. In the DEM simulations, vibration parameters, including vibration frequency, vibration amplitude and stroke angle, and swing parameters, including swing frequency and swing angle, were changed to perform parametric studies.

It shows that the effect of particle shape on screening efficiency is quantitative actually. However, the trends of different shape particles’ screening efficiency per unit time are mainly consistent.

Some simple particle shapes can be expected to be explored to do screening simulation studies reasonably with modification of the simulation data in DEM numerical simulations. That may improve the computational efficiency of numerical simulations and provide guidance to the study of the screening process.

Particles in granular matter can have very different and irregular shapes. The computational treatment of nonspherical objects is a major difficulty in the simulation of granular flows. In this paper, two basic strategies for contact resolution between objects described by level surfaces are presented and analyzed. They are based on the iterative solution of systems of nonlinear equations. The major difficulties are pinpointed and necessary steps toward a generic algorithm are proposed. A test case of colliding cardioids in two dimensions is used to demonstrate the algorithms and illustrate common pitfalls.

The purpose of this paper is to present a simple non‐symmetric shape, the poly‐ellipsoid, to describe particles in discrete element simulations that incur a computational cost similar to ellipsoidal particles.

Particle shapes are derived from joining octants of eight ellipsoids, each having different aspect ratios, across their respective principal planes to produce a compound surface that is continuous in both surface coordinate and normal direction. Because each octant of the poly‐ellipsoid is described as an ellipsoid, the mathematical representation of the particle shape can be in the form of either an implicit function or as parametric equations.

The particle surface is defined by six parameters (vs the 24 parameters required to define the eight component ellipsoids) owing to dependencies among parameters that must be imposed to create continuous intersections. Despite the complexity of the particle shapes, the particle mass, centroid and moment of inertia tensor can all be computed in closed form.

The particle can be implemented in any contact algorithm designed for ellipsoids with minor modifications to determine in which pair of octants the potential contact occurs.

The poly‐ellipsoid particle is a computational device to represent non‐spherical particles in DEM models.

This paper aims to explore the influence of a particular label surface texture, i.e. embossing, on consumer purchase intentions and willingness to pay. This paper further highlights the underlying mechanisms explaining this relationship by unveiling the mediating role of willingness to touch and perceived package uniqueness.

Based on the visual salience theory and the stimulus–organism–response (SOR) model, this paper tests mediations and serial mediations across two online experiments and evidence from a laboratory experiment.

Study 1 reveals perceived package uniqueness as the mediator, such that embossed elements on the label increase perceived uniqueness, hence leading to greater purchase intentions and willingness to pay. In addition, Study 2 replicates these results and goes further by demonstrating the positive effect of embossing on purchase intentions and willingness to pay through willingness to touch then perceived package uniqueness.

The findings provide insightful managerial implications by drawing attention to the importance of using embossed elements on packaging, particularly when companies seek to differentiate themselves from competitors by stimulating consumers to touch their product packaging and having them perceive their products as unique.

Using visual salience theory and the SOR model, this research is, to the best of the authors’ knowledge, the first to shed light on the effect of embossing as a visual element of the packaging design on willingness to touch the product (haptics) and perceived uniqueness, ultimately enhancing purchase intentions and willingness to pay.

The purpose of this paper is to investigate the unsteady flow past through a permeable diamond-shaped cylinder and to study the effects of the aspect ratios and Darcy numbers of the cylinder.

The lattice Boltzmann method with D2Q9 lattice model was used to simulate the unsteady flow through permeable diamond-shaped cylinders. The present numerical method is validated against the available data.

The key findings are that increasing the permeability enhances the suppression of vortex shedding, and that the Strouhal number is directly proportion to the Darcy number, Reynolds number and the aspect ratio of the porous cylinder.

The present study considers unsteady laminar flow past through single permeable diamond-shaped cylinder. According to the authors’ knowledge, very few studies have been found in this field. The present findings are novel and original, which in turn can attract wide attention and citations.