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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=653942
• 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.

注意[]是指CCV中的期刊出版物。申请人的小组在浸入涂料和插槽涂层以及微注射成型方面具有丰富的经验 - 在开发高增值设备的主要加工技术中，涂层具有功能性（例如，导电性，光扩散）或保护性（例如氧气或氧气（例如，氧气或防水屏障，损坏保护））。 电池，有机光电导体和微电机械设备等设备的尺寸和复杂性需要在纳米长度较小的尺度上更加精确到微米长度。 研究目标是更好地了解多相系统中粒子流的机制，这可能导致粒子沉积，粘附和团聚。考虑到颗粒上的力，将研究粒子 - 固体相互作用和粒子流体相互作用的性质，并包括颗粒和流体之间的两种耦合。具有挑战性的领域之一将是掺入非牛顿流体效应，因为许多涂层都是聚合物矩阵中的颗粒分散体。最近的研究集中在使用颗粒浓度的流体模型以及使用离散元素方法（DEM）进行插入涂层[2,8]中的浸入涂料[7,10]。 在这两种应用中，都使用开源CFD软件（OpenFOAM），精确地确定涂料膜的界面位置并捕获流动中颗粒的影响时，存在严重的困难。 关于流动，导致颗粒颗粒和颗粒壁相互作用的粒子表面特性以及在所有这些应用中都存在的自由表面的作用的问题仍然出现问题。实验验证的仿真将为了解这些竞争效果的作用，并为使用这些制造方法的设备的设计和生产提供更好的设计和生产。 对于不连续的涂料技术（基本上是印刷），诸如印刷电子，电池涂料和基板上的高价值功能材料等不连续的涂料技术（基本上是打印）也具有相当大的科学兴趣。 膜边缘的精确位置受游离表面的影响：液体固体，局部表面张力，表面润湿性和颗粒的存在之间的接触线。 对这种系统的仿真是一个科学兴趣的领域，可以更好地了解对粒子分布的竞争影响，并且是设计和生产设备所必需的 - 这项研究将有助于更好地建模产品设计和过程改进工具。