不同种类冰晶的分子扩散
The Molecular Diffusion of Ice Crystals of Various Shapes
摘要：
通过分子扩散（舍伍德数（Sh）表示的不同形状的冰晶的舍伍德数（Re）= 0）的生长使用将电容（C）与Sh相关联的电模拟来计算。虽然以前已经获得了云物理学中感兴趣的各种冰晶的Sh对Re的依赖性的实验数据，但将数据外推到Re=0的较小颗粒是不可靠的。我们提出了一个简单的计算算法，用于计算Sh在Re=0的各种晶体的利益，这将允许适当的覆盖范围内适用于冰晶的整个Re范围。我们提出的方法可以应用于任何直线形状的晶体。办法如下：将模型晶体放置在盒子中，并在晶体和盒子之间施加电场，模拟冰晶的初始生长阶段。使用可变晶格间距的有限笛卡尔网格系统，将冰晶的角分配给特定的晶格点，从而定义晶体的几何形状。高斯通量定律的离散版本的开发和使用这个晶格系统。Sh（在Re=0）得到的六角板，六角柱，广泛的分支晶体，恒星晶体，并加盖柱。我们的计算表明，我们简单的计算算法提供了这些形状的Sh值在5%以内的误差，通过估计在以前的研究中获得的值。
英文摘要：
The growth by molecular diffusion (Reynold's number (Re) = 0) of ice crystals of different shapes, represented by the Sherwood number (Sh) is calculated using an electrical analog which relates capacity (C) to Sh. Although experimental data on dependence of Sh on Re for various ice crystals of interest in cloud physics have been previously obtained, extrapolation of the data to smaller particles for Re=0 has been unreliable. We present a simple computational algorithm for computing Sh at Re=0 for various crystals of interest, which will allow proper coverage over the whole Re range applicable to ice crystals. The method we present can be applied to any crystal of rectilinear shape. The approach was as follows: the model crystal is positioned in a box and an electric field is applied between the crystal and the box, simulating the initial growth stage of ice crystals. Using a finite Cartesian grid system of variable lattice separations, the corners of ice crystal are assigned to particular lattice points, thereby defining the geometry of the crystal. A discrete version of Gauss' flux law is developed and used for this lattice system. Sh (at Re=0) is obtained for hexagonal plates, hexagonal columns, broad branched crystals, stellar crystals, and capped columns. Our calculations reveal that our simple computational algorithm provides the values of Sh for these shapes to within 5% error from the values obtained through estimates in previous studies.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
