论文标题
共振引起的rbne-bne隔离反转的颗粒混合物的加速度
Resonance-induced acceleration of the RBNE-BNE segregation inversion of granular mixtures
论文作者
论文摘要
本文介绍了有关谐振诱导的反向巴西坚果效应(RBNE) - 巴西坚果效应(BNE)隔离反转二元混合物在平底和圆形容器中二元混合物的偏析的实验和模拟。实验和仿真结果都表明,在平底容器中触发了顶层较重晶粒的下沉的起始位置,而它首先出现在圆形容器底部的任何一个底部边缘。模拟中的量化隔离因子表明,从RBNE隔离状态到BNE隔离状态的过渡在圆形容器中的发生速度要比平底容器中的圆形容器更快。较高和较低颗粒温度的站立谐振斑点的发生加速了RBNE-BNE隔离反转。从单晶粒的弹性碰撞模型,底部的角度更大,从垂直方向到水平方向的能量转移更多。理论预测通过单分散颗粒床的模拟证实。平底容器具有均匀的分布,具有颗粒温度和堆积密度的站立周期,而圆形容器在水平方向上具有较高的颗粒温度,在圆形底部的侧向边缘处具有较低的堆积密度。由于浮力效应,较重的晶粒很容易首先在温度较高的谐振斑点下沉入。
This paper presents the experiments and simulations on the resonance-induced acceleration of the reverse Brazil nut effect (RBNE)-Brazil nut effect (BNE) segregation inversion of binary mixtures in flat-bottom and circular-bottom containers. Both experimental and simulation results indicate that the starting location of the sinkage of heavier grains at the top layer is triggered with certain randomness in the flat-bottom container, whereas it first occurs at either of the lateral edges of the bottom in the circular-bottom container. The quantified segregation factors in simulations show that the transition from the RBNE segregation state to the BNE segregation state happens faster in the circular-bottom container than that in the flat-bottom container. The occurrence of standing-wave resonant spots of higher and lower granular temperature accelerates the RBNE-BNE segregation inversion. From the elastic collision model of single grain, the bottom with a larger angle leads to more energy transfer from the vertical direction to the horizontal direction. The theoretical predictions are confirmed by the simulations of a monodisperse granular bed. The flat-bottom container has a uniform distribution with a standing-wave period of granular temperature and packing density, whereas the circular-bottom container possesses a higher granular temperature in the horizontal direction and a lower packing density at the lateral edges of the circular bottom. Owing to the buoyancy effect, heavier grains easily sink first at the resonant spots with higher temperature.