Sandoval Mario, Jimenez Alonso
Department of Physics, Universidad Autonoma Metropolitana-Iztapalapa, Mexico, Distrito Federal, 09340, Mexico.
J Biol Phys. 2016 Mar;42(2):199-212. doi: 10.1007/s10867-015-9401-4. Epub 2015 Oct 1.
The motion of viruses and bacteria and even synthetic microswimmers can be affected by thermal fluctuations and by external flows. In this work, we study the effect of linear external flows and thermal fluctuations on the diffusion of those swimmers modeled as spherical active (self-propelled) particles moving in two dimensions. General formulae for their mean-square displacement under a general linear flow are presented. We also provide, at short and long times, explicit expressions for the mean-square displacement of a swimmer immersed in three canonical flows, namely, solid-body rotation, shear and extensional flows. These expressions can now be used to estimate the effect of external flows on the displacement of Brownian microswimmers. Finally, our theoretical results are validated by using Brownian dynamics simulations.
病毒、细菌乃至合成微游动体的运动都会受到热涨落和外部流动的影响。在这项工作中，我们研究线性外部流动和热涨落对那些被建模为在二维中运动的球形活性（自推进）粒子的游动体扩散的影响。给出了它们在一般线性流动下均方位移的通用公式。我们还在短时间和长时间情况下，给出了浸没在三种典型流动（即刚体旋转、剪切流和拉伸流）中的游动体均方位移的显式表达式。这些表达式现在可用于估计外部流动对布朗微游动体位移的影响。最后，我们通过布朗动力学模拟验证了理论结果。
