Flow structures generated by elongated plates settling in a water column

In order to establish a mathematical formulation of the equation of motion, the trajectory of particles settling in a stagnant fluid has been studied for generations. The publication by Field et al. [4] is one of the more well-known studies, where the dynamic behaviour of disks as function of the dimensionless moment of inertia and Reynolds number was investigated. The objective of the present work is to collect and present experimental data about the flow structures generated by the settling of elongated plates in a water column. The experiments are carried out by releasing the plates at an initial angle of 15° in a 0.60 m x 0.30 m  0.35 m (LBH) glass container filled with water. Continuous Particle Image Velocimetry is used to analyse both the velocity field of the continuous phase and the motion of the plates. The experiments show a well-defined oscillating motion of the plate. A stall occurs each time the plate changes horizontal direction of motion. The results show a flow building up when the plate accelerates and a vortex rolling off in each turn.