Computational investigation of drag forces on bluff bodies induced by interacting non-circular particles in a vertical channel using the fictitious boundary method.

This article investigates the numerical behavior of non-circular particles—specifically elliptical, pentagonal, and square shapes—falling and interacting with fixed circular obstacles (cylinders) within a fluid channel. Using the fictitious boundary method combined with the finite element method and a modified collision model, the study analyzes particle trajectories, positional tracking, and drag coefficients under various obstacle arrangements (inline and staggered) and gap distances. Results indicate that particle shape, obstacle positioning, and gap size significantly influence particle paths and settling times, with pentagonal particles settling fastest and elliptical particles most affected by fluid interactions and collisions. The findings have potential applications in sediment transport modeling, vascular flow simulations, and industrial particulate flow processes.