Molecular Dynamics Simulation of Micro-Droplet Motion on Solid Surface Induced by Temperature Gradient
Molecular Dynamics Simulation of Micro-Droplet Motion on Solid Surface Induced by Temperature Gradient
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温度梯度引起的固体表面微液滴运动的分子动力学模拟
DOI：
10.1299/kikaib.72.987
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
S. Mochizuki
中科院分区：
文献类型：
--
作者：
A. Murata;S. Mochizuki
采用分子动力学方法，对具有温度梯度的固壁面上纳米液滴的运动进行了数值模拟。由铂（Pt）固体壁（面心立方，表面为（1 1 1））构成，并在其上形成氩（Ar）液滴，Ar分子数为1000、2000和4000。半圆柱形液滴的Pt原子数为8000或16000，半球形液滴的Pt原子数为32000或72000。壁面平均温度为90 K，最大温度梯度为2× 109 K/m。在等温壁面上，液滴停留在初始位置附近，并有一定的波动。当温度梯度施加到壁时，液滴明显地向较低温度侧移动。在半球形液滴的情况下，更强的流体-固体相互作用的情况下，即，较高的润湿性和较低的接触角的情况下，速度较大。另一方面，半圆柱形液滴情况下，流固相互作用强度对速度的影响没有表现出明确的趋势。在目前的计算条件下，施加的温度梯度并没有作出明显的差异的轮廓的时间平均的相互作用力施加在流体分子上的固体分子，当比较低温和高温侧。
Motion of a nanoscale droplet on a solid wall with temperature gradient was numerically simulated by using the molecular dynamics method. The platinum (Pt) solid wall (fcc with surface of (1 1 1)) was composed, and the argon (Ar) droplet was formed on it. The number of Ar molecule was 1000, 2000, and 4000. The number of Pt atom was 8000 or 16000 for the semi-cylindrical droplet, and 32000 or 72000 for the hemispherical droplet. The mean wall temperature was 90 K, and the maximum temperature gradient was 2×109K/m. On the isothermal wall, the droplet stayed around the initial location with some fluctuation. When the temperature gradient was applied to the wall, the droplet clearly moved toward the lower temperature side. In the hemispherical droplet case, the velocity was larger for the stronger fluid-solid interaction case, that is, the higher wettability and the lower contact angle case. On the other hand, the semi-cylindrical droplet case did not show a definite tendency in the effect of the fluid-solid interaction intensity on the velocity. Within the present computational conditions, the imposition of the temperature gradient did not make a distinct difference in the profile of the time-averaged interaction force exerted on the fluid molecules by the solid molecules, when compared between low and high temperature sides.