En
期刊文章
文章精选
当期目录
过刊浏览
高被引
高下载
特邀文章
专刊合集
待刊文章
Volume 111
您当前的位置：首页 > 期刊文章 > 过刊浏览 > Volumes 108-119 (2025) > Volume 111
Quantifying streamers instabilities in 2D particle sedimentation using DNS (Open Access)
Xiaoqi Li a b *, Xiaotao Bi a
a Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
b Petroleum Engineering Department, Colorado School of Mines, Golden, CO, 80401, USA
10.1016/j.partic.2026.01.030
Volume 111, April 2026, Pages 136-149
Received 30 October 2025, Revised 22 December 2025, Accepted 26 January 2026, Available online 6 February 2026, Version of Record 19 February 2026.
E-mail: xiaoqi.li@ubc.ca; onlyviolet.lee@gmail.com
Highlights

• Streamer induced mesoscale instabilities in 2D sedimentation are quantified using DNS.

• A filtered framework links local solid fraction, slip velocity, and drag variations.

• A new DNS based H-index measures streamer orientation and intensity.

• Streamer anisotropy dominates local drag deviation from homogeneous conditions.

• The framework provides physical insights for closure models in multiphase simulations.


Abstract

Particle streamers formed dynamically strongly influence hydrodynamics in gas–solid multiphase flows, yet their quantitative characterization in sedimentation remains incomplete. We performed a direct numerical simulation (DNS) of quasi-2D particle sedimentation process using the lattice Boltzmann method (LBM) coupled with hard-sphere collisions to resolve both gas–particle and particle–particle interactions. Simulations span solid volume fractions of 0.15 and 0.40, density ratios of 100 and 1000, and terminal Reynolds numbers Re0 = 3 and 30, corresponding to Stokes numbers St = 17–1667. Structure factor analysis identifies distinct instability modes: dilute systems develop bypassing and plug-funnel structures, whereas dense systems form void-like regions with retarded particle-gas coupling at high St. Domain averaged sedimentation velocities from DNS are compared with Richardson-Zaki and Yin correlations, showing enhanced settling at low St and hindered settling due to persistent plugs at high St. Filter based analysis of local drag demonstrates significant deviations from classical drag laws, with drag reduction in dense phases. Statistical analysis of velocity fluctuations reveals anisotropy, negative skewness linked to plug formation, and departure from Gaussian distributions. To quantify mesoscale heterogeneity, we introduced a heterogeneous index (H-index), which captures orientation dependent fluctuations in DNS fields. Results reveal that streamers are scale-dependent, which modify drag and sedimentation velocity through mesoscale heterogeneities in the flow field. These findings provide quantitative insights into the mechanisms governing gas-solid interactions and particle segregations in sedimentation systems.

Graphical abstract
Keywords
Gas-solid flow; Streamers; DNS; Sedimentation; Scale-dependent
文章导读