关键词: 纳米科学, 扫描隧道显微术, 纳米结构, 分子电子学

Abstract: A one-dimensional model is established to simulate the axial flow patterns in a downer reactor. Based on the gas–solid continuity equation and the momentum equation, the model takes the variation of superficial gas velocity in the downer into account. The gas and solid velocity and the voidage distribution is emphatically studied. The simulation results show that there exists a remarkable disparity of axial flow pattern between variable superficial gas velocity and fixed gas velocity conditions. The linearly variable superficial velocity condition is more close to a downer reactor in practical operation.

Key words: downer, variable superficial gas velocity, one-dimensional model