关键词: 圆筒形容器, 颗粒食品, 颗粒间正压力, 颗粒间摩擦力, 颗粒与容器间正压力

Abstract: In this study,a model of particulate packing was established to predict pressure and friction force of spherical particulate food in cylindrical container. The model assumed that equal-sized spherical particles of food are parked in a quasihexagonal structure and divied into many layers. Force equilibrium and transfer equations were derived for each layer and solved consecutively to determine normal pressures and friction forces between two particles and between particle and container. The numerical results showed that as depth of particulate food increases the normal pressures and friction forces between two particles and between particle and container increase. As internal friction angle of particulate food increases,normal pressures between two particles and between particle and container wall decrease,but friction forces between two particles and normal pressures between particules and bottom of container increase. As diameter of container increases,normal pressures between particles and between particle and container increase in the same height. As coefficient of friction of container wall increases,normal pressures between two particles and between particle and container decrease. As apparent density of particulate food decreases,normal pressures between two particles and between particle and container wall decrease,but friction forces between two particles and normal pressures between particules and bottom of container increase. Normal pressures between two particles and between particle and container are 2.66 to 26.33 times of friction forces between two particles,and normal pressures between particules and bottom of container are 1.74 to 1.89 times of normal pressures between two particules and between particules and wall of container in the layer above bottom.

Key words: cylindrical container, particulate food normal pressures between particules, friction forces between particles, normal pressures between particules and container