基于粘度影响的稀薄效应下壁面速度滑移的数学建模
发布时间：2018-11-26 16:05
【摘要】：以气膜分层理论为基础,根据近壁层、稀薄层、连续流层内分子运动形式,结合层内黏度的变化特征,建立壁面滑移模型,并给出相应的数学表达式。通过LAMMPS和2DMD数值分析的方法,结合实验测试结果发现:在稀薄层内,沿竖直方向的速度呈线性变化,越靠近壁面,速度越小;在近壁层内,由于分子与壁面的摩擦使得近壁层分子速度骤减;在连续流层内,气体分子做全滑移运动;此外,温度越高,黏度越小,速度滑移越大,近壁层与稀薄层速度差值越大。温度一定时,无量纲滑移长度和Kn数成线性关系。
[Abstract]:Based on the theory of gas film stratification, the wall slip model is established according to the molecular motion forms in the near wall layer, the thin layer and the continuous flow layer, and the variation characteristics of the viscosity in the layer, and the corresponding mathematical expressions are given. By means of LAMMPS and 2DMD numerical analysis, combined with the experimental results, it is found that in the thin layer, the velocity along the vertical direction changes linearly, the closer the wall is, the smaller the velocity is. In the near wall layer, the molecular velocity of the near wall layer decreases because of the friction between the molecule and the wall layer, and in the continuous flow layer, the gas molecule makes the whole slip motion. In addition, the higher the temperature, the smaller the viscosity and the greater the velocity slip, the greater the velocity difference between the near wall layer and the thin layer. When the temperature is constant, the dimensionless slip length is linearly related to the Kn number.
【作者单位】： 昆明理工大学机电工程学院;
【基金】：国家自然科学基金(51305185)资助
【分类号】：TH117.2
，
本文编号：2359012
[Abstract]:Based on the theory of gas film stratification, the wall slip model is established according to the molecular motion forms in the near wall layer, the thin layer and the continuous flow layer, and the variation characteristics of the viscosity in the layer, and the corresponding mathematical expressions are given. By means of LAMMPS and 2DMD numerical analysis, combined with the experimental results, it is found that in the thin layer, the velocity along the vertical direction changes linearly, the closer the wall is, the smaller the velocity is. In the near wall layer, the molecular velocity of the near wall layer decreases because of the friction between the molecule and the wall layer, and in the continuous flow layer, the gas molecule makes the whole slip motion. In addition, the higher the temperature, the smaller the viscosity and the greater the velocity slip, the greater the velocity difference between the near wall layer and the thin layer. When the temperature is constant, the dimensionless slip length is linearly related to the Kn number.
【作者单位】： 昆明理工大学机电工程学院;
【基金】：国家自然科学基金(51305185)资助
【分类号】：TH117.2
，
本文编号：2359012
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