Investigation of Continuous-Flow Mixing of Non-Newtonian Fluids through Advanced Flow Visualization Techniques (e.g. Tomography and Ultrasonic Velocimetry) and Computational Fluid Dynamics

非牛顿流体的混合在化学、生物化学、食品、聚合物、纸浆和造纸、化妆品、废水处理和制药工业中起着重要作用。以前的研究主要集中在批处理模式下非牛顿流体的混合，而关于这些复杂流体的连续混合的信息很少。连续流混合在大多数化学和相关的过程工业中很普遍，因为它提供了高生产率，改进了过程控制，节省了操作时间和人工成本。在我们的研究实验室中进行的研究表明，非牛顿流体的复杂流变性会产生非理想流动（例如通道、再循环和死区），这极大地影响了连续流混合器的效率。全面的文献综述表明，我们目前对非牛顿流体连续混合的理解和实施不足以确保良好的混合。目前非牛顿流体连续混合的设计是基于有限的公开信息和试错法。事实上，这个问题还没有得到充分的描述，显然有必要更详细地探讨这个主题。因此，我们的长期研究计划目标是开发方法和工具，通过先进的流动可视化技术（例如断层扫描和超声波测速）和先进的计算流体动力学（CFD）方法，为具有复杂流变的流体设计连续混合系统。这项工作对加拿大的化学工业具有重要意义。混合是一个关键的单元操作，并没有充分发挥其潜力。不提供必要的混合可能会导致严重的制造问题，从昂贵的工厂修正到一个过程的完全失败。据估计，仅在北美化工行业，每年因混合不良造成的损失就高达100亿美元。提出的实验和建模研究计划将提高我们对非牛顿流体连续混合的理解，并使我们能够制定可靠的设计准则。应用本研究的结果将改善连续混合过程中的变异性减少。这将节省资金成本，降低化学品成本，改进设备设计和选择，更可靠的过程监控和控制，增加现有工厂的吞吐量，提高产品质量，并更有效地利用电力。因此，拟议的研究将有助于增加加拿大化学工业的经济活动，并将影响我们的社会、生活质量、健康和环境。它还将有助于教育和培训混合技术、先进流动可视化技术、计算流体动力学、流变学以及动态建模和识别领域的高素质人才。

The mixing of non-Newtonian fluids plays a significant role in chemical, biochemical, food, polymer, pulp and paper, cosmetic, wastewater treatment, and pharmaceutical industries. Previous studies have focused on the mixing of non-Newtonian fluids in the batch mode and little information is available regarding the continuous-flow mixing of these complex fluids. Continuous-flow mixing is prevalent in most of chemical and allied process industries because it provides high production rates, improves process control, and saves operation time and labor costs. The studies conducted in our research lab show that the complex rheology of non-Newtonian fluids creates non-ideal flows (e.g. channeling, recirculation, and dead zone) that significantly affect the efficiency of continuous-flow mixers. A comprehensive literature review reveals that our current understanding and implementation of continuous mixing of non-Newtonian fluids is insufficient to ensure good mixing. The current design of continuous mixing of non-Newtonian fluids is based on limited published information, and trial and error method. In fact, this issue has not been fully delineated yet and there is a clear need to explore this topic in more detail. Thus, our long term research program goal is to develop methodology and tools to design continuous mixing systems for fluids with complex rheology through advanced flow visualization techniques (e.g. tomography and ultrasonic velocimetry) and advanced computational fluid dynamics (CFD) methods. The work is of great importance to the chemical industry of Canada. Mixing is a critical unit operation and is not operating to its fullest potential. Failure to provide the necessary mixing may result in severe manufacturing problems ranging from costly corrections in the plant to complete failure of a process. The annual loss due to poor mixing is estimated at $10 billion in the North America chemical industry alone. The proposed experimental and modeling research program will improve our understanding of continuous mixing of non-Newtonian fluids and enable us to develop the reliable design criteria. Applying the findings of this study will improve variability reduction in the continuous mixing processes. This will lead to capital cost savings, chemical cost reduction, improved equipment design and selection, more reliable process monitoring and control, increased throughput for existing plant, improved quality of products, and more efficient use of power. Thus, the proposed research will contribute to the increased economic activity of the Canadian chemical industry, and will impact our society, quality of life, health and environment. It will also contribute to the education and training of highly qualified personnel (HQP) in the field of mixing technology, advanced flow visualization techniques, computational fluid dynamics, rheology, and dynamic modeling and identification.