随机调制速度场中的反常扩散
Anomalous diffusion in a randomly modulated velocity field
AI总结:
该研究提出一种偶极矩随机调制的偶极子速度场反常扩散模型,作为湍流流体粒子反常扩散的玩具模型,数值模拟得到二维、三维下轨迹分形维数分别为1.5-1.9、1.6-2.7。
摘要:
本文提出了一种简单的反常扩散模型:粒子在单个“dipole(偶极子,即源汇对或 doublet 偶极子)”诱导的速度场中运动,偶极矩在每个时间步长被随机调制。引入该模型的动机是它可作为玩具模型,用于研究湍流中流体粒子的反常扩散现象。我们在二维和三维空间中采用周期性边界条件,对轨迹的分形维数进行了数值模拟。在较大的偶极矩取值范围内,我们估算得到轨迹的分形维数在二维中为1.5--1.9,在三维中为1.6--2.7。
英文摘要:
This paper proposes a simple model of anomalous diffusion, in which a particle moves with the velocity field induced by a single "dipole" (a doublet or a pair of source and sink), whose moment is modulated randomly at each time step. A motivation to introduce such a model is that it may serve as a toy model to investigate an anomalous diffusion of fluid particles in turbulence. We perform a numerical simulation of the fractal dimension of the trajectory using periodic boundary conditions in two and three dimensions. For a wide range of the dipole moment, we estimate the fractal dimension of the trajectory to be 1.5--1.9 (2D) and 1.6--2.7 (3D).
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。