Drag, lift, and torque correlations for axi-symmetric rod-like non-spherical particles in linear wall-bounded shear flow

TL;DR

This study develops and validates new correlations to accurately predict the hydrodynamic forces on axi-symmetric rod-like particles in wall-bounded shear flows, considering particle orientation, aspect ratio, and wall proximity.

Contribution

The paper introduces novel correlations for drag, lift, and torque of non-spherical particles near walls, derived from DNS data and previous studies, with high accuracy.

Findings

Correlations show median errors below 12%.

High correlation coefficients (above 0.96) demonstrate strong agreement with DNS.

Applicable for large-scale CFD/DEM simulations of non-spherical particles.

Abstract

This paper presents novel correlations to predict the drag, lift, and torque coefficients of axi-symmetric non-spherical rod-like particles in a wall-bounded linear shear flow. The particle position and orientation relative to the wall are varied to systematically investigate the influence of the wall on the hydrodynamic forces. The newly derived correlations for drag, lift, and torque on the particle depend on various parameters, including the particle Reynolds number, the orientation angle between the major axis of the particle and the main local flow direction, the aspect ratio of the particle, and the dimensionless distance from the particle centre to the wall. The coefficients of the correlations are determined through a fitting process utilizing the data generated from our previous study on the interaction forces between a locally uniform flow and an axi-symmetric non-spherical rod-like particles, as well as from data of novel direct numerical simulations (DNS) performed in this work of flow past axi-symmetric rod-like particles near a wall. The proposed correlations exhibit a good agreement compared to the DNS results, with median errors of 2.89%, 5.37%, and 11.00%, and correlation coefficients of 0.99, 0.99, and 0.96 for the correlations accounting for changes in drag, lift, and torque coefficients due to the wall-bounded linear shear flow profile, respectively. These correlations can be used in large-scale simulations using an Eulerian-Lagrangian or a CFD/DEM framework to predict the behaviour of axi-symmetric rod-like non-spherical particles in wall-bounded flows, shear flows, as well as uniform flows.