Numerical simulation and investigation of micro-flows with immersed nano-structures based on the Dissipative Particle Dynamics method

本文拟采用数值模拟方法研究浸入式纳米线对液体微通道流动的影响。相应的流型难以用现有的计算方法模拟。利用分子动力学（MD），人们可以有效地计算多达10万个液体粒子，这相当于一个边长为10纳米的立方体的计算体积。然而，流体的连续介质模型不能考虑微观尺度上的影响。对于提议的项目，需要一种能够同时描述流体中微观和宏观效应的方法。耗散粒子动力学（DPD）方法通过粗颗粒化来模拟微观尺度的现象，从而得到中尺度的描述。它的效率比MD高几个数量级。然而，与连续介质模型不同的是，它还允许直接模拟复杂的流体行为。这是有效应用于微纳米级流动的先决条件。拟建项目的主要课题是：a)开发和实施DPD方法来研究微纳米尺度的流动；B)浸没纳米线微通道中液体流动的物理性质和行为研究；C)算法的性能分析和并行化。作为该项目的结果，一个计算工具将可以更广泛地应用于具有浸入纳米级结构的复杂微流。

We propose to investigate liquid micro-channel flows with immersed nano-wires by numerical simulation. The corresponding flow regime is difficult to simulate with existing computational methods. With Molecular Dynamics (MD) one can efficiently compute nowadays upto about 100 000 liquid particles, which corresponds to a computational volume of a cube with a side-wall length of 10 nm. Continuum models of a fluid, however, cannot take effects on the microscopic scale into account. For the proposed project a method is required which is able to describe simultaneously micro- and macroscopic effects in a fluid. The Dissipative Particle Dynamics (DPD) approach models micro-scale phenomena by coarsegraining, resulting in a mesoscale description. It is several orders of magnitude more efficient than MD. Unlike the continuum model, however, it also allows to model complex fluid behavior directly. This is the prerequisite for an efficient application to micro- and nanoscale flows. Main topics of the proposed project are: a) development and implementation of a DPD method to study micro- and nanoscale flows; b) investigation of physical properties and behavior of liquid flow in micro-channels with immersed nano-wires; c) performance analysis and parallelization of the algorithm. As a result of the project a computational tool will be available which can be applied more generally to complex micro-flows with immersed nanoscale structures.