Multiscale modeling of granular and solid-liquid flows in chemical engineering processes

颗粒流在许多工业的化学过程中普遍存在，例如纸浆和造纸、制药、石油、食品、家庭护理和化妆品。这种类型的流动表现出复杂的行为，尽管在基础和应用研究的最新进展，仍然知之甚少。例如，在制药工业中，由于缺乏关于固体形式药物制造中的制粒、混合和压片操作的机制的知识，因此这些工艺的设计通常是通过经验方法实现的。牙膏、洗发水和面霜代表了由悬浮在载液中的颗粒组成的结构化流体的示例，其生产具有挑战性，因为这些多方面的最终用途产品的性质必须仔细控制。该研究计划的目标是通过开发模拟此类系统中的流动动力学的准确和实用的模型来深入了解颗粒系统的行为。更确切地说，我们的工作导致了精确的计算机模型的开发，我们已经用来模拟混合设备中干颗粒的混合，以及阐明化学反应器和纸张涂层应用中的颗粒流动。在这种情况下，我们的工作将旨在完善我们目前的模型，使它们能够有效地处理更复杂和越来越逼真的颗粒系统，例如那些表现出各种颗粒形状并发挥颗粒间力的颗粒系统。该研究计划还侧重于计算流体动力学，更确切地说，是开发用于调查各种应用中发生的不可压缩流体流动的鲁棒多尺度模型，特别是在固液混合和过滤中。 该研究计划的好处包括更好地了解颗粒系统的流动行为，以及开发涉及干燥颗粒或多相固液流的更有效和可控的化学工程过程。最后，它将能够培训高素质的化学工程师，以设计和操作涉及各种粉末和颗粒的化学工艺。

Particulate flows are ubiquitous in the chemical processes of many industries such as the pulp and paper, pharmaceutical, petroleum, food, household care and cosmetics. This type of flows exhibits complex behavior that, in spite of recent progress in fundamental and applied research, still remains poorly understood. In the pharmaceutical industry, for instance, the lack of knowledge concerning the mechanisms governing the granulation, blending and tableting operations in the manufacturing of solid form drugs is such that the design of these processes is generally achieved by empirical methods. Toothpastes, shampoos and face creams represent examples of structured fluids made up of particles suspended in a carrier liquid, the production of which is challenging because the properties of these multifaceted end-use products must be carefully controlled. The objective of this research program is to gain insight into the behavior of particulate systems by developing accurate and practical models that simulate the flow dynamics in such systems. More precisely, our work has led to the development of accurate computer models that we have used to simulate the mixing of dry particles in blending equipment as well as to shed light on particulate flows in chemical reactors and paper coating applications. In this context, our work will aim at refining our current models so that they can deal efficiently with more complex and increasingly realistic particulate systems, such as those that exhibit various particle shapes and bring into play interparticle forces. This research program also focuses on computational fluid dynamics and, more precisely, on the development of robust multiscale models for the investigation of incompressible fluid flows occurring in various applications, notably in solid-liquid mixing and filtration. The benefits of this research program include a better understanding of the flow behavior of particulate systems, and the development of more efficient and controllable chemical engineering processes involving dry granular or multiphase solid-liquid flows. Finally, it will enable the training of highly qualified chemical engineers for the design and operation of chemical processes involving powders and particles of all kinds.