Computational investigation of drag and settling behavior of micro-meso plastic particles

Plastic particles are commonly observed within fluid mediums across various natural and industrial processes. Their movement and behavior, from river sedimentation to erosion, ocean deposition, and fluidized bed particle transport, present several instances. Understanding the drag coefficient and settling velocity of these particles is vital for practical applications. This research investigates the settling behavior of spherical/non-spherical regular plastic particles through both numerical simulations and experiments conducted in a 2500 mm height and diameter of 300 mm cylindrical water test column. High-speed cameras record particle movement at a frame of 50 fps, focusing on various particle shapes including box-shaped prisms, cylinders, half cylinders, spheres, and spherical sectors. Results from the numerical simulations are validated with experimental findings and, the applicability of the numerical approach beyond controlled experimental settings demonstrated. The numerical results exhibit a maximum deviation of 17% from the experimental data. Possible factors contributing to this variation are explored and discussed.