Numerical analysis of frictional behavior of dense gas–solid systems--颗粒学报PARTICUOLOGY

Ghadirian, E., & Arastoopour, H. (2017). Numerical analysis of frictional behavior of dense gas–solid systems. Particuology, 32, 178-190. https://doi.org/10.1016/j.partic.2017.01.001

Numerical analysis of frictional behavior of dense gas–solid systems

Emad Ghadirian ^a *, Hamid Arastoopour ^{b c}

a Gamma Technologies, LLC., 601 Oakmont Ln, Suite 220, Westmont, IL 60559, USA
b Department of Chemical and Biological Engineering, Illinois Institute of Technology, Chicago, IL 60616, USA
c Wanger Institute for Sustainable Energy Research, Illinois Institute of Technology, Chicago, IL 60616, USA

10.1016/j.partic.2017.01.001

Volume 32, June 2017, Pages 178-190

Received 22 September 2015, Revised 1 November 2016, Accepted 19 January 2017, Available online 7 April 2017, Version of Record 20 April 2017.

E-mail: eghadiri@hawk.iit.edu

Highlights

• An L-valve was modeled using actual solid frictional pressure.

• Critical solid frictional pressure underestimated the frictional forces in dense particle flow.

• A new approach was devised capable of predicting angle of repose more accurately.

• Effects of different parameters on the solid flow in the frictional regime were studied.

Abstract

Dense gas–solid flows show significantly higher stresses compared with dilute flows, mainly attributable to particle–particle friction in dense particle flows. Several models developed have considered particle–particle friction; however, they generally underestimate its effect in dense regions of the gas–solid system, leading to unrealistic predictions in their flow patterns. Recently, several attempts have been made to formulate such flows and the impact of particle–particle friction on predicting flow patterns based on modified frictional viscosity models by including effects of bulk density changes on frictional pressure of the solid phase. The solid–wall boundary is also expected to have considerable effect on friction because particulate phases generally slip over the solid surface that directly affects particle–particle frictional forces. Polydispersity of the solid phase also leads to higher friction between particles as more particles have sustained contact in polydispersed systems. Their effects were investigated by performing CFD simulations of particle settlement to calculate the slope angle of resting material of non-cohesive particles as they settle on a solid surface. This slope angle is directly affected by frictional forces and may be a reasonably good measure of frictional forces between particles. The calculated slope angle, as a measure of frictional forces inside the system are compared with experimental values of this slope angle as well as simulation results from the literature.

Graphical abstract

Keywords

Solid frictional pressure; Particle–particle frictional forcesL-valve; Computational fluid dynamics (CFD); Polydispersity; Angle of repose

文章导读