| dc.description.abstract | This study employs a quasi-two-dimensional rectangular container as the bed, using cylindrical particles with the same volume but different aspect ratios (AR) as the background particles. Through experiments, the rising behavior of an intruder in a vibrated granular bed is investigated under varying vibration frequencies and dimensionless vibration accelerations. The experiments on granular segregation involve cylindrical particles with aspect ratios of 0.67, 1.3, 2.25, 3.66, and 5.33. High-speed cameras captured the particle motion, and Particle Image Velocimetry (PIV) with MATLAB was employed for image processing and analysis. The analysis focuses on the intruder′s rising time, rising velocity at different stage, granular temperature of the background particles, bulk density of the background particles and the rising resistance of the intruder, aiming to understand the segregation behavior and flow dynamics of the intruder among cylindrical particles with different aspect ratios.
Experimental results show that increasing frequency leads to longer rising times for the intruder, and the rising time increases with the AR of cylindrical particles. This is because, for AR > 1, the bulk density of the particles decreases, resulting in higher porosity, which facilitates separation between the intruder and the background particles. Thus, higher aspect ratios result in shorter rising times. At low vibration accelerations, the intruder′s rising velocity decreases with increasing height due to the increasing bulk density, which reduces the flow of background particles beneath the intruder in the later stages. Analyzing the background particle temperature near the bed′s bottom approaches zero over time due to packing effects. These findings demonstrate that the motion of cylindrical particles in a vertical vibrated bed is significantly influenced by shape-induced packing effects, which affect the flow properties of the granular bed. | en_US |