Modelling the wetting / dewetting of solid particles.

涉及液体涂覆固体颗粒（“润湿”）或从颗粒去除液体涂层（“去润湿”）的方法在工业中是常见的。加拿大最著名的例子来自阿尔伯塔，那里的油砂经过加工，分离出覆盖在沙子上的沥青。类似的分离过程可以在许多其他行业中找到，包括食品，药品和采矿。另一方面，有一些工艺的目标是将液体涂层施加到固体颗粒上。尽管可能看起来是简单的过程，颗粒润湿和去湿现象是非常复杂的，并且关于这些过程如何发生的许多问题仍然没有答案。本提案旨在开发一个复杂的计算机模型来模拟这些基本现象，然后使用该模型在基本层面上检查润湿和去湿，更多地了解它们是如何工作的，并将这种理解应用于工业规模上更有效和更有效的过程的开发。我们将在一个名为OpenFOAM（openfoam.org）的开源软件中开发模拟功能，而不是从头开始构建计算机模型，该软件已被全球数千名工程师和科学家使用。这项建议涉及两项主要任务。首先是增加该软件的功能：引入不同形状的固体颗粒，这些颗粒将被允许随着流动而移动;以及模拟润湿和去湿现象的算法。 第二项任务是使用新软件研究一些基本现象：液体薄膜从单个球形颗粒和非球形颗粒（如椭球体）中分离;两个或多个包覆颗粒的行为，以研究何时以及是否从一个颗粒上去除包覆层只会导致另一个颗粒的包覆;在不同种类的流动中，一簇包覆颗粒的行为;以及最后，未包覆颗粒从一种液体进入另一种液体时的行为，以及颗粒何时以及在何种程度上保留一些第一液体作为包覆层。

Processes that involve a liquid coating a solid particle ("wetting"), or the removal of a liquid coating from a particle ("dewetting"), are commonplace in industry. The best-known Canadian example comes from Alberta, where oil sands are processed to separate the bitumen that coats sand. Similar separation processes can be found in many other industries, including the food, drug, and mining. On the flip side, there are processes where the goal is to apply a liquid coating to a solid particle. Despite what may appear to be simple processes, particle wetting and dewetting phenomena are very complex, and many questions remain unanswered about how such processes take place. This proposal is for the development of a sophisticated computer model to simulate such basic phenomena, and then to use the model to examine wetting and dewetting at a fundamental level, to learn more about how they work, and to apply that understanding to the development of more efficient and effective processes at the industrial scale.**Rather than build the computer model from scratch, we will develop the simulation capabilities within an open-source software called OpenFOAM (openfoam.org) that is already used by thousands of engineers and scientists worldwide. The proposal involves two main tasks. The first is to add capabilities to this software: the introduction of solid particles of different shapes, that will be allowed to move with a flow; and algorithms to mimic wetting and dewetting phenomena. The second task is to then use the new software to examine a number of basic phenomena: the separation of a thin film of liquid from a single spherical particle, and from non-spherical particles like ellipsoids; the behaviour of two or more coated particles, to examine when and whether removing a coating from one particle simply leads to the coating of another; the behaviour of a cluster of coated particles in different kinds of flows; and finally, the behaviour of an uncoated particle as it passes from one liquid to another, and when and to what extent the particle retains some of the first liquid as a coating.