A numerical study of wall pressure and granular flow in a flat-bottomed silo

Abstract

JY 2015, 'A numerical study of wall pressure and granular flow in a flat-bottomed silo ', Powder Technology, vol. 282,. https://doi. AbstractThis paper presents a numerical study of the granular flow in the discharge of a flat-bottomed model silo.The behaviour of the stored granular material is modelled using the finite element (FE) method based on an Arbitrary Lagrangian-Eulerian (ALE) frame of reference, which has shown advantageous performance over the classical FE methods in simulating the silo filling and discharge process in a series of studies leading up to this investigation. Experimental results have been used to validate the computational model using the ALE technique. The spatial distribution and time history of the pressures acting on the vertical silo walls predicted by the FE model are found to resemble well the test results. A semi-mass flow pattern has been predicted by the numerical model, which is very consistent with the corresponding experimental observation. With the validated numerical model, the flow behaviour specifically under a flat-bottomed geometry of silos is examined. Based on the velocity distribution in the granular material, a critical velocity ratio criterion is proposed and used to identify the flow channel boundary. A further numerical study has shown that the flow behaviour in the flat-bottomed silo is closely related to the shear strength of the material, which is represented by the internal friction angle for the cohesionless sand considered in the present study.

Quantitative comparison of hydrodynamic and elastoplastic approaches for modeling granular flow in silo

“…The elastoplastic models μ s and μ(I) use a rigid yield criterion to determine whether flow occurs, thus the transition between stagnant and flowing zones is narrow and sharp, resembling the shear localization or slipping lines in large‐scale and fine‐particle systems. In hydrodynamic models, since the value of viscosity must be bounded by a finite value η max , the transition between stagnant and flowing zones is more continuous, which seems closer to the observation on small‐scale systems, although η max is introduced primarily for numerical reason without explicit physical ground.…”

Modeling granular material blending in a rotating drum using a finite element method and advection‐diffusion equation multiscale model

“…Zheng and Yu used the finite element method (FEM) assuming Mohr‐Coulomb continuum material behavior to predict material velocity and stress fields in rotating drums and hoppers . Other researchers have attempted similar FEM continuum modeling efforts for describing powder flow, but with varied success . The advantages of assuming continuum material behavior are that (a) simulations at an industrial scale can be performed as tracking individual particles is not required, and (b) material characterization is straightforward, using standardized shear cell equipment for example.…”

Análise comparativa de pressões horizontais durante o carregamento em silos verticais metálicos

“…Na Figura 5, o silo com relação h/d = 1 apresenta valores de até 80% de inferioridade, quando comparados as normas em estudo, quando a zona em questão é imediatamente superior a zona de transição entre o corpo do silo e a tremonha. Wang et al (2015) por sua vez, ao realizarem um trabalho com simulação de pressões, encontram valores de pressões experimentais próximos aos valores obtidos através da simulação e até 20% inferiores aos valores a partir da norma BS EN 1991:4, sendo possível assim afirmar que, para a situação imposta, a simulação representa perfeitamente as ações causadas pelo produto armazenado as paredes do silo.…”