Numerical Simulation and Analysis of Particle Mixing and Conduction in Wavy Drums

Abstract

A thermal -discrete element method (DEM) is used to simulate particle mixing and heat conduction inside wavy drums to explore the effects of wavy walls. Sinusoidal configurations with different waves on the walls are simulated. The Lacey mixing index is applied to analyze the mixing characteristics. The driven forces from the wavy wall, either positive/negative or effective driven forces, are analyzed to explain the mechanisms of mixing enhancement in the wavy drum. A new control parameter is proposed to explain the mechanism of mixing enhancement. It is found that a locally oscillating effect exists in wavy drums, which is imparted on the bulk rotating motions of particles, and enhances the characteristics of particle mixing and heat conduction significantly. Except over large wave numbers and rotating speeds when the flow regime is deteriorated for mixing, the wavy drum is generally beneficial for mixing augmentation as well as conduction enhancement.

TDEM simulation and analysis of thermal conduction through packed granular beds

“…As a result, the granular material can be utilized for production of catalysts, oxides, fertilizers and powder foods, etc. The properties of particles, such as size [8], shape [9], density [10], conductivity [11], concentration [12] and so on, will have great impact on flow and thermal behavior of particles, such as the heating or insulating capacity. For example, Grah et al [13] presented a modeling study of radial heat transfer in catalyst packing, and paid attention to the tube/particle diameter ratios.…”

Effect of pebble size and bed dimension on the distribution of voidages in pebble bed reactor

“…Many researchers have studied the two-dimensional and three-dimensional models via the DEM method. 23–26 In this paper, the software which is named OpenFOAM and the soft sphere model which is one of the models in the DEM are used to simulate the static accumulation of the three kinds of core pebbles under the same load under two-dimensional and three-dimensional conditions, and the influence of the size and dimension of the core pebbles was studied quantitatively to improve the voidage study in the fixed bed of HTR-10.…”