Multiscale modeling of multiphase flows in chemical engineering processes

多相流可以在制药、石油、汽车、食品和家居护理等广泛行业的化学过程中找到。这种流动行为复杂，与单相流相比，尽管在实验和模拟技术方面取得了重大进展，但人们对它的了解仍然很少。例如，汽车微粒过滤器的行为本质上是多相和瞬时的，因为它们涉及到在构成这些过滤器通道的多孔壁内捕获微小的气载烟尘颗粒。由于对这些颗粒和废气排放的限制越来越严格，需要更好地了解这些过滤器的捕集机制和催化转化器中气体在车辆排气管路上的转化所涉及的输送现象。工业中发现的另一个复杂系统的例子包括用于固体形式药物制造的混合操作的设计和放大，由于缺乏对管理机制的了解，通常是通过经验实现的。我们还可以提到洗发水、牙膏和个人护理用品的生产，这些产品是由悬浮在载体液体中的非常微小的颗粒组成的结构性液体。这是具有挑战性的，因为必须仔细控制这类最终用途产品的性能。这一正在进行的研究计划的目标是继续我们在多相系统建模方面的努力，重点是固体-流体过程，通过开发准确、稳健和可用的多尺度模型来模拟此类系统中的流动动力学和传输现象。我们的兴趣是将这些模型应用于干燥颗粒和固液混合过程，以及涉及多孔介质的应用，如过滤操作中的应用。这项研究计划将更好地了解各种与工业相关的颗粒系统，涉及不同流变性的固体颗粒和液体的不同分布。它还将能够培训高素质的化学工程师，以设计、控制和扩大由各种粉末和颗粒组成的化学过程。

Multiphase flows can be found in the chemical processes of a wide range of industries such as pharmaceutical, petroleum, automotive, food and household care. Such flows behave in a complex manner and, in comparison to single phase flows, remain poorly understood despite significant progress in both experimental and modeling techniques. For instance, the behavior of automobile particulate filters is both multiphase and transient in nature, as they involve the capture of small gas-borne soot particles inside the porous walls that make up the channels of these filters. Owing to the increasing strict limits on the emission of these particles as well as that of exhaust gas, a better understanding of the transport phenomena governing the capture mechanisms of such filters and the gas conversion in catalytic converters along the exhaust lines of vehicles is needed. Another example of complex systems found in the industry includes the design and scale-up of blending operations for the manufacturing of solid form drugs often achieved empirically due to the lack of knowledge of the governing mechanisms. We can also cite the production of shampoos, toothpastes and personal care commodities, which are structured fluids comprised of very small particles suspended in a carrier liquid. This is challenging because the properties of such end-use products must be carefully controlled. The objective of this on-going research program is to pursue our efforts in the modeling of multiphase systems, with an emphasis on solid-fluid processes, by developing accurate, robust and usable multiscale models for the simulation of the flow dynamics and transport phenomena in such systems. Our interest is to apply these models to dry granular and solid-liquid mixing processes, and to applications involving porous media such as those in filtration operations. This research program will provide a better understanding of a variety of particulate systems of industrial relevance, involving varying distributions of solid particles and liquids of different rheological behaviors. It will also enable the training of highly qualified chemical engineers for the design, control and scale-up of chemical processes comprising powders and particles of all kinds.