Molecular dynamics simulation is used to study flow rate behavior of monoatomic fluid through carbon nanotube (CNT) against the pore diameter. All armchair and zigzag CNTs with diameters below 1.5 nm were considered. Fluid flow rate versus diameter is investigated, and discrepancy was observed in the results. Its non-monotonic behavior is reported and attributed to diameter-dependent potential energy landscape in CNT. Effects of CNT length and pressure difference on flow rate as well as radial distribution function were examined as an additional check to ensure that the physical behavior of the model is correct. The deviation of fluid atoms from the minimum point in potential function is found to be significantly effective on the fluid–solid friction force experienced by fluid atoms, and consequently on the flow rate values. Also, investigating short periods of time shows that fluid atoms move discontinuously in the course of their passage through CNT. Consequently, distribution of atoms shows certain dense spots, similar to peaks in radial distribution which is well known and examined in the previous literature. Extremely low flow rate in some cases of CNT diameter and chirality shows that care should be taken in designing novel nanoscale devices which are built based on fluid flow and its properties in CNTs.

中文翻译：

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流体流过薄碳纳米管的异常行为

分子动力学模拟用于研究单原子流体通过碳纳米管 (CNT) 的流速行为与孔径的关系。考虑了直径低于 1.5 nm 的所有扶手椅和锯齿形碳纳米管。研究了流体流速与直径的关系，并在结果中观察到了差异。其非单调行为被报道并归因于碳纳米管中直径相关的势能景观。检查了 CNT 长度和压差对流速的影响以及径向分布函数，作为额外的检查，以确保模型的物理行为是正确的。发现流体原子与势函数中的最小值点的偏差对流体原子所经历的流固摩擦力非常有效，因此对流速值也很有效。还，短时间研究表明，流体原子在通过 CNT 的过程中是不连续移动的。因此，原子的分布显示出某些密集点，类似于径向分布中的峰值，这在以前的文献中是众所周知的和检查过的。在某些 CNT 直径和手性情况下的极低流速表明，在设计基于流体流动及其在 CNT 中的特性的新型纳米级器件时应小心谨慎。