关键词: 气相沉积法, 气体流场, 纤维模型, 数值模拟, 纤维运动形态

Abstract:

In order to study the motion morphology of carbon nanotube fibers in a vapor deposition reactor and the impact of motion morphology on the formation of carbon nanotube fibers, this paper first employs the method of numerical simulation to solve the gas flow field in the vapor deposition reactor numerically and then figures out the velocity of gas flow field in the reactor. After that, a carbon nanotube fiber model is built in this gas flow field and a force analysis is conducted to obtain a fiber dynamics equation. Combined with the gas flow field control equation set, we can get a fiber/gas two-phase flow model. Finally, the fiber dynamics equation is solved numerically, with the gas velocity in the reactor obtained through calculation, so as to get the motion morphology of carbon nanotube fibers in the reactor. The simulation results indicate that the gas flow field in the vapor deposition reactor presents a laminar flow state. Since the gas flows in from the center, there is a great fluctuation near the central axis of the fiber reactor. The gas flow area near the central axis gradually expands, and the direction of acceleration changes, making the direction and magnitude of gas velocity change accordingly. The undulating entanglement of fibers can increase the bond of fibers in the fiber bundle, making it difficult to spread out. The gas flow near the wall gradually becomes stable, making the fiber motion near the wall gradually flatten out. The motion morphology of fibers obtained through simulation has a good promoting effect on the formation of carbon nanotube fiber bundles.

Key words: chemical vapor deposition, gas flow field, fiber model, numerical simulation, motion morphology of fiber