Multiphase flows of particles in thin film systems

薄膜系统中颗粒的多相流

• 批准号: RGPIN-2017-04101
• 负责人: Hrymak, Andrew
• 金额: $ 2.04万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=710853
• 关键词: Multiphase; flows; particles; thin; film

Note [] refers to journal publications in CCV. The focus of this research is on the nature of flow of particle filled fluids, in multiphase thin films, in flows of industrial interest for the creation of functional devices or thin film coatings. The Applicant's group has considerable experience in dip coating and slot coating, as well as micro-injection molding - major processing technologies in the development of high value added devices where the coating is either functional (e.g. electrically conductive, light diffusion) or protective (e.g. oxygen or water barrier, damage protection). The size and complexity of devices such as batteries, organic photoconductors and microelectromechanical devices requires more precision at smaller length scales on the nano to microns length scale. The research objective is to better understand the mechanisms of particle flows in multiphase systems that may lead to particle deposition, adhesion, and agglomeration. The nature of the particle-solid interactions and particle-fluid interactions will be studied, taking into account the forces on the particles, and including two way coupling between the particles and the fluid. One of the challenging areas will be the incorporation of non-Newtonian fluid effects, as many coatings are particle dispersions in polymer matrices. Recent research has focused on dip coating [7,10] using fluid models that incorporate particle concentration, and in slot coating [2,8] using the discrete element method (DEM) to track individual particles. In both applications, using open source CFD software (OpenFOAM), there were serious difficulties in precisely determining the position of the interface of the coating film and in capturing the effects of particles within the flow. Questions still arise as to the competing forces due to flow, particle surface properties leading to particle-particle and particle wall interactions, and the role of free surfaces, which exist in all these applications. Simulation with experimental validation will provide a valuable tool in understanding the role of these competing effects and lead to better design and production of devices that use these manufacturing methods. There is also considerable scientific interest in discontinuous coating technologies (essentially printing) for applications such as printed electronics, battery coatings and high value functional materials on substrates. The precise location of the film edges are affected by the free surfaces: contact lines between liquid-solid, local surface tension, wettability of the surface and presence of particles. Simulation of such systems is an area of scientific interest to better understand the competing effects on the particle distribution, and necessary to design and produce devices - this research will contribute to better modeling tools for product design and process improvement.

注[]指CCV期刊出版物。 这项研究的重点是多相薄膜中颗粒填充流体的流动性质，以及用于创建功能器件或薄膜涂层的工业利益流动。申请人的团队在浸涂和槽涂以及微注射成型方面拥有丰富的经验，微注射成型是开发高附加值设备的主要加工技术，其中涂层具有功能性（例如导电、光扩散）或保护性（例如光扩散）。氧气或水屏障，损坏保护）。 电池、有机光电导体和微机电器件等器件的尺寸和复杂性要求在纳米到微米长度尺度上的较小长度尺度上具有更高的精度。 研究目的是更好地了解多相系统中可能导致颗粒沉积、粘附和团聚的颗粒流机制。将研究颗粒-固体相互作用和颗粒-流体相互作用的性质，考虑颗粒上的力，并包括颗粒和流体之间的双向耦合。具有挑战性的领域之一是结合非牛顿流体效应，因为许多涂料是聚合物基体中的颗粒分散体。最近的研究重点是使用包含颗粒浓度的流体模型的浸涂[7,10]，以及使用离散元方法（DEM）跟踪单个颗粒的狭缝涂布[2,8]。 在这两个应用中，使用开源 CFD 软件 (OpenFOAM) 时，在精确确定涂膜界面的位置以及捕获流内颗粒的影响方面存在严重困难。 关于所有这些应用中存在的流动引起的竞争力、导致颗粒与颗粒和颗粒壁相互作用的颗粒表面特性以及自由表面的作用，仍然存在一些问题。实验验证模拟将为理解这些竞争效应的作用提供一个有价值的工具，并有助于更好地设计和生产使用这些制造方法的设备。 对于印刷电子、电池涂层和基材上的高价值功能材料等应用的不连续涂层技术（本质上是印刷）也有相当大的科学兴趣。 薄膜边缘的精确位置受到自由表面的影响：液固之间的接触线、局部表面张力、表面的润湿性和颗粒的存在。 此类系统的模拟是一个具有科学意义的领域，可以更好地理解对颗粒分布的竞争影响，并且是设计和生产设备所必需的 - 这项研究将有助于为产品设计和工艺改进提供更好的建模工具。