Investigation of continuous-flow mixing of non-newtonian fluids through tomography, ultrasonic velocimetry and computational fluid dynamics techniques

非牛顿流体的连续流混合是许多过程的重要组成部分，包括聚合、发酵、废水处理、纸浆和造纸，因为它能够提高产品的均匀性，并最大限度地减少停机、装卸时间。目前非牛顿流体的连续混合设计是基于有限的公开信息和试错方法。传统上采用理想混合假设来设计这些混合过程。然而，非牛顿流体所表现出的复杂流变特性可能与理想的混合产生相当大的偏差。研究表明，短路、再循环和死区等非理想流动对连续混合过程的性能有显著影响。事实上，对文献的彻底搜索表明，我们目前对非牛顿流体连续混合的理解和实现不足以确保良好的混合。特别是，需要结合混合动力学的设计标准，以便从连续混合系统中获得可接受的混合响应。因此，长期研究计划的目标是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方法，开发方法和工具来设计具有复杂流变的流体的连续混合系统。这项工作对加拿大的化学工业具有重要意义。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[工业混合手册]。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，并回答有关设计标准的一些基本问题。应用本研究的发现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，提高产品质量，并更有效地利用电力。本研究将积极吸引博士生和硕士生参与，为培养高素质人才做出贡献。

Continuous-flow mixing of non-Newtonian fluids is a vital component to many processes including polymerization, fermentation, waste water treatment, and pulp and paper manufacturing because of its demonstrated ability to improve product uniformity and minimize shut down, loading and unloading times. The current design of continuous mixing of non-Newtonian fluids is based on limited published information, and trial and error methods. The assumption of ideal mixing has traditionally been used to design these mixing processes. However, the complex rheology displayed by non-Newtonian fluids can create considerable deviation from ideal mixing. Studies show that the non-ideal flow such as short circuiting, recirculation, and dead zones significantly affect the performance of continuous mixing processes. In fact, a thorough search of the literature suggests that our current understanding and implementation of continuous mixing of non-Newtonian fluids is insufficient to ensure good mixing. In particular, design criteria incorporating mixing dynamics are needed so that acceptable mixing responses can be attained from continuous mixing systems. Thus, the 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 methods. The work is of great importance to the chemical industry of Canada. The annual loss due to poor mixing is estimated at $10 billion in the North America chemical industry alone [Handbook of Industrial Mixing]. The proposed experimental and modeling research program will improve our understanding of continuous mixing of non-Newtonian fluids and answer some of the fundamental questions about the design criteria. Applying the finding of this study will improve variability reduction in the continuous mixing processes. This will lead to capital cost savings, chemical cost reduction, improved quality of products, and more efficient use of power. The proposed research will contribute to the training of highly qualified personnel by actively involving Ph.D. and master's students.