Lbm-DEM Simulation of Particle-Laden Flows in the Presence of Liquid Bridge Forces

LBM-DEM simulation of particle-laden
flows in the presence of liquid bridge forces

Hongsheng Chen ¹,
Sheng Chen ¹, Shuiqing Li ^1,*, and Zhaoli Guo ²

¹
Key Laboratory for
Thermal Science and Power Engineering of Ministry of Education, Department of
Energy and Power Engineering, Tsinghua University, Beijing 100084, China

²
State Key
Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan
430074, China

Abstract: Air flows, carrying
micron-sized particles, occur extensively in numerous fields of interest such
as aerosols, dust removing and pharmaceuticals. As well known, micron-sized
particles become extremely cohesive due to the presence of liquid bridge
forces, being responsible for various complex phenomena involved in gas-solid
flows, e.g., clustering, aggregation and clogging. In this study, the dynamics
of microparticles passing over a circular cylinder in
a channel flow is numerically investigated at mesoscale by combining a
multi-relaxation-time lattice Boltzmann method with a multiscale discrete
element method. Sliding, rolling and twisting resistances between colliding particles
are taken into consideration, and the presence of liquid bridge introduces additional
capillary cohesion, liquid viscous damping and liquid viscous torque to the
particle-particle and particle-wall interactions. The fluid-solid interaction
is achieved by the momentum exchange method, considering solid surfaces as
bounce-back boundaries. The Weber number is applied to discuss the capture of wet
microparticles by the circular cylinder, as well as the
behavior of wet microparticles in the wake behind the
circular cylinder. Therefore, this research is of certain importance for a
better understanding of the roles of liquid bridge forces playing in the
dynamics of microparticles carried by viscous fluids
and in the capture of microparticles by an obstacle.

Keywords: particle-laden flows, wet
particles, fluid-solid interaction, LBM-DEM