在纳米碳裂中剪切驱动水流的水力动力滑动特性
Abdul Aziz Shuvo1, Luis E Paniagua-Guerra1, Xiang Yang1
1Department of Mechanical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
The Journal of chemical physics
|May 15, 2024
概括
在水-石墨接口中的水力动态滑动长度 (LS) 显示了对剪切速率的双模反应. 接口模型显示LS取决于密度耗尽,而不是粘附,在高剪速下滑率更高.
科学领域:
- 物理化学 物理化学
- 材料科学 材料科学 材料科学
- 计算物理 计算物理
背景情况:
- 液动力学滑动长度 (LS) 对于界面上的流体运输至关重要.
- 固体-液体相互作用的准确建模对于预测LS至关重要.
- 非平衡分子动力学 (NEMD) 提供了一个强大的工具来研究切割下的界面现象.
研究的目的:
- 调查切割速率和接口建模参数对水力动力滑动长度 (LS) 对水石墨系统的影响.
- 探索LS,界面性质和质行为之间的关系.
- 为了阐明在不同剪切条件下观察到的滑动行为背后的机制.
主要方法:
- 使用了非平衡分子动力学 (NEMD) 模拟.
- 使用了五个不同的非结合的固体-液体相互作用参数,由电子结构计算和经验数据提供信息.
- 用水模型 (SPC/E和TIP4P/2005) 来评估结果的可靠性.
主要成果:
- 在所有接口模型中观察到对切割速率的双模 LS 响应.
- 低切割速率 (LSR) 的LS与平衡分子动力学结果一致.
- LS与剪切速度急剧增加,在高剪切率 (HSR) 中达到平原,LHSR大约比LLSR大28%.
- 在这两种方案中,密度耗尽长度的特征是LS,而不是粘附度量.
- 界面摩擦系数的动态解释了LS从LSR向HSR的转变.
结论:
- 水力动力滑动长度强烈依赖于切割速率和接口建模参数.
- 密度耗尽是控制滑动的一个关键因素,而不是固体-液体粘附.
- 双模滑动行为归因于在剪速过渡期间的界面摩擦和剪切粘度的明显反应.
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