Combined effects of internal friction and bed height on the Brazil-nut problem in a shaker

We experimentally studied the influence of an intruderʹs friction coefficient and bed-filling height on the Brazil-nut effect in a quasi-2D vertical vibration granular bed. The motion of intruder was successfully measured using a high-speed camera and the rising time of intruder was determined by using a particle tracking method with the help of image processing technology. The results show that an intruderʹs friction coefficient and filling bed height play significant roles in the rise dynamics. The results also show that the rise time increases when the intruderʹs friction coefficient increases, which is reduced when the filling bed height decreases. Penetration length and friction drag force were also determined in this study. The penetration length was reduced and the friction drag force was enhanced with the increase of an intruderʹs friction coefficient and bed height. Additionally, the variation between the rise times of the smooth and rough intruders was not significant with the lower bed-filling heights.