论文标题
流体滑动流动的混合连续分子模型
Hybrid continuum-molecular modeling of fluid slip flow
论文作者
论文摘要
微/纳米尺度固体输送机中流体系统的实验表明，经典流体力学已采用了无滑动假设。为了纠正流体滑移的这种力学，已经提出了各种方法来确定滑动边界条件。但是，这些方法揭示了各种系统的矛盾结果，并且关于流体滑移/不滑动固体表面的机制和条件的争论很长一段时间。在本文中，我们建立了混合连续分子模型（HCMM），作为在多余的流体固定分子相互作用的影响下对流体滑动进行建模的一般方法。这种建模方法假设流体在固体表面上流动，而没有滑移，具体取决于流体上施加的脉冲和由于多余的流体固定分子相互作用而引起的阻力之间的差异。在HCMM中，对于多余的流体固定相互作用，对Navier-Stokes方程进行了校正。流体 - 固定相互作用的度量被纳入流体粘度。我们证明，通过滑动边界条件对流体力学进行校正不是准确的方法，因为流体 - 固定相互作用会在内部影响流体。为了显示拟议的HCMM的有效性，它是用于纳米管中的水流的。 HCMM通过与不同流体系统的90例实验和分子动力学模拟进行了广泛的比较来验证。我们预见到流体滑动流的混合连续分子建模将在流体力学中找到许多重要的实现。
Experiments on fluid systems in micro-/nano-scale solid conveyors have shown a violation of the no-slip assumption that have been adopted by the classical fluid mechanics. To correct this mechanics for the fluid slip, various approaches have been proposed to determine the slip boundary conditions. However, these approaches have revealed contradictory results for a variety of systems, and a debate on the mechanisms and the conditions of the fluid slip/no-slip past solid surfaces is sustained for a long time. In this paper, we establish the hybrid continuum-molecular modeling (HCMM) as a general approach of modeling the fluid slip flow under the influence of excess fluid-solid molecular interactions. This modeling approach postulates that fluids flow over solid surfaces with/without slip depending on the difference between the applied impulse on the fluid and a drag due to the excess fluid-solid molecular interactions. In the HCMM, the Navier-Stokes equations are corrected for the excess fluid-solid interactions. Measures of the fluid-solid interactions are incorporated into the fluid viscosity. We demonstrate that the correction of the fluid mechanics by the slip boundary conditions is not an accurate approach, as the fluid-solid interactions would impact the fluid internally. To show the effectiveness of the proposed HCMM, it is implemented for water flow in nanotubes. The HCMM is validated by an extensive comparison with over 90 cases of experiments and molecular dynamics simulations of different fluid systems. We foresee that the hybrid continuum-molecular modeling of the fluid slip flow will find many important implementations in fluid mechanics.
