The effect of rotational Brownian motion on Witten–Sander aggregates
The effect of rotational Brownian motion on Witten–Sander aggregates
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DOI：
10.1063/1.451107
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发表时间：
1986-08
影响因子：
4.4
通讯作者：
H. Hentschel;J. Deutch;P. Meakin
中科院分区：
文献类型：
--
作者：
H. Hentschel;J. Deutch;P. Meakin
研究了旋转扩散对Witten-Sander聚集体生长的影响。对一个模型进行了计算机模拟分析，其中增长的聚集体以旋转扩散常数Drot（R_（max））/[τrot（R_（max）/a）δ]旋转，而不可逆聚集的颗粒以扩散率α 2/τ0跳跃（τ0，τrot是平移和旋转跳跃的时间常数，a是晶格间距）。在模拟中，0.0002<（τ0/τrot）<1600在七个数量级上变化。一般来说，聚集体是各向异性的（尽管模型具有固有的对称性），具有纵向和横向长度尺度R和R。在尺度r R上，集群仍然是分形的，但在尺度R r R上，集群变成线性的。本文估计了R_∞对N、（τ_0/τ_rot）和δ的依赖关系，并与计算机数据作了比较。初始和渐近行为进行了研究，并确定了几个制度的增长。
The effect of rotational diffusion on the growth of Witten–Sander aggregates is examined. Computer simulations of a model are analyzed where the growing aggregate rotates with a rotational diffusion constant Drot(R∥)∼1/[τrot(R∥/a)δ], while the irreversibly aggregating particles jump with a diffusivity a2/τ0(τ0,τrot are the time constants for translational and rotational jumps and a is the lattice spacing). In the simulations 0.0002<(τ0/τrot)<1600 is varied over seven orders of magnitude. In general the aggregates are anisotropic (despite the inherent symmetry of the model) with longitudinal and transverse length scales R∥ and R⊥. On scales r≪R⊥ the cluster remains fractal, but on scales R⊥≪r≪R∥ the cluster becomes linear. Estimates of the dependence of R∥ on N, (τ0/τrot), and δ are made and compared with the computer data. Both initial and asymptotic behavior are investigated, and several regimes of growth identified.