介观尺度下热对流对颗粒两相流动影响的eDPD研究

项目名称： 介观尺度下热对流对颗粒两相流动影响的eDPD研究

项目编号： No.51476150

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 能源与动力工程

项目作者： 刘汉涛

作者单位： 中北大学

项目金额： 78万元

中文摘要： 有热对流影响的介观尺度颗粒两相流动涉及复杂的动力学特性。基于连续力学的网格方法，通常很难捕捉边界滑移、热扰动等的影响，也未必适用于含多尺度特性的各种问题，而分子动力学时间及空间尺度通常局限于纳秒和纳米级。本项目拟建立用以模拟介观尺度下有热对流影响的颗粒两相流动的能量守恒耗散粒子动力学(eDPD)方法和相关理论体系。为此在固液界面模型、eDPD动力学参数、eDPD参数与物理参数映射、eDPD数学模型等几个方面进行研究，填补以往对此类问题研究的不足。通过粒子图像测速（PIV）实验、直接数值模拟(TDNS)对方法检验和验证。在此基础上，揭示微通道内该复杂多相流流场的结构特征和其流动、传热的物理规律，总结一些重要的无量纲特征数与流场特征变化之间的规律，从中得到新的信息并从理论上进行阐述。本项目拟为微尺度传热机理研究、微流体器件开发等生化工程和微纳米科技中的传热问题提供详细的介观尺度数值模拟信息。

中文关键词： 能量守恒耗散粒子动力学；两相流；介观尺度；热对流；流固界面

英文摘要： Multiphase flows in meso-scale channels with thermal convection involve complicated dynamic behaviors. Grid-based numerical methods within the frame of continuum mechanics are usually difficult to capture inherent flow physics such as boundary slip and thermal disturbance. They also may be not valid to problems with multiple scale physics. In contrast, molecular dynamics (MD) is practical only on extremely small time scales (nanoseconds) and length scales (nanometers) even if the most advanced high-performance computers are used. The purpose of this project is to simulate the fluid-solid systems with the effect of thermal convection at mesoscopic scale utilizing dissipative particle dynamics with energy conservation (eDPD). More specifically, four fundamental problems relating to eDPD will be investigated: the fluid-solid interface treatment algorithms, the dynamic behaviour of eDPD fluid, the mapping of eDPD units to physical units, the constitutive relation and boundary conditons. The obtained numerical results will be compared with experimental observations from particle-imaging velocimetry (PIV) and ture direct numerical simulation (TDNS). Based on the above procedure, the detailed mechanisms of fluid-solid system with the effect of thermal convection will be explored. Thereafter the relationship between the characteristic numbers and the flow field will be investigated. The proposal, by supplying with detailed mesoscopic eDPD simulation information, aims at understanding the fundamentals in terms of biochemical engineering, science and technology at mesoscale relating to convective heat transfer research and development of MEMS devices.

英文关键词： dissipative particle dynamics with energy conservation (eDPD);two-phase flow;mesoscale;thermal convection;fluid-solid interface