Multiphase multilayer viscoplastic displacement flows: Controlling interfacial patterns

一种流体被另一种通常具有不同性质的流体置换发生在各种自然和工业应用中。难以实现的目标通常是通过施加的驱替流体完全去除原位驱替流体，同时流体-流体界面积极参与流动动力学。与这个具有根本挑战性的流体力学问题相关，我们的研究计划的长期愿景围绕开发先进的流动模型/模拟和新颖的实验，以改善加拿大处理置换流的工业过程，其复杂，多相，多层，界面和非牛顿性质至关重要。实例包括石油和天然气威尔斯井的堵塞和废弃中的移除/清洁过程中的位移流，以及铝生产、清洁/移除和去污以及注塑成型中的各种过程。在这些和类似的工业过程中使用的流体和材料经常表现出非牛顿粘塑性特性，当考虑触变性和粘弹性瞬态响应时，流变学变得更加复杂。这些复杂性，沿着高度非线性和难以预测的界面行为，使得控制这些复杂的界面驱替流极其困难。在这种情况下，我们的愿景是开发突破性的方法和策略，以有效地控制多相，多层粘塑性流体的推进和渗透。这可以例如通过控制/操纵时空界面演化和阻碍/触发界面现象来实现，以根据我们的设计和需要实现期望的位移流动模式/状态。反过来，这使我们能够精确地预测/设计各种工业过程中的复杂位移行为，并减少这些流动的不可预测性/不可控制性所带来的负面影响。在这个框架中，我们的具体短期目标是提出变革性的控制位移策略，通过分析（i）不混溶的粘塑性位移在旋转管道，（ii）位移与超疏水壁的流动几何形状，和（iii）触变弹粘塑性位移流。这些有趣的研究课题通过新颖的复杂流体实验（例如激光/相机/超声成像），严格的半分析数学模型（润滑，渐近和稳定性分析模型）以及依赖于开源代码的先进计算流体动力学方法进行研究。通过让研究生和本科生参与进来，这些在我们的研究计划中接受过培训的高素质人员将体验到独特的教育环境，该环境专为复杂流动的数学和实验建模而设计，即对专业知识和技能需求不断增加的研究领域。

The displacement of one fluid by another fluid of usually different properties occurs in a variety of natural and industrial applications. The hard-to-achieve objective is typically to completely remove the in-situ displaced fluid, via the imposed displacing fluid, while the fluid-fluid interface participates actively in the flow dynamics. Relevant to this fundamentally-challenging fluid mechanics problem, our research program's long-term vision revolves around developing advanced flow models/simulations and novel experiments, to improve Canadian industrial processes dealing with displacement flows, whose complex, multiphase, multilayer, interfacial and non-Newtonian nature are critical. Examples include displacement flows in removal/cleaning processes in the plug and abandonment of oil&gas wells, as well as various processes in aluminum production, cleaning/removal and decontamination, and injection molding. The fluids and materials used in these and similar industrial processes frequently exhibit non-Newtonian viscoplastic properties, for which the rheology becomes even more complex when thixotropy and viscoelastic transient responses are considered. These complexities, along with highly non-linear and hard-to-predict interfacial behaviour, make it extremely hard to control these complex interfacial displacement flows. In this context, our vision is to develop ground-breaking methods and strategies to effectively control the advancement and penetration of multiphase, multilayer viscoplastic fluids into one another. This can be realized, for example, via controlling/manipulating the spatiotemporal interface evolution and hindering/triggering interfacial phenomena, to achieve desired displacement flow patterns/regimes, according to our design and needs. This in return enables us to precisely predict/design complex displacement behaviours in a broad range of industrial processes, and reduce concomitant negative impacts of unpredictability/uncontrollability of these flows. In this framework, our specific short-term objectives are to propose transformative controlling displacement strategies, via the analysis of (i) immiscible viscoplastic displacements in rotating pipes, (ii) displacements in flow geometries with superhydrophobic walls, and (iii) thixo-elasto-visco-plastic displacement flows. These fascinating research topics proposed are investigated through novel complex fluid experiments (e.g. laser/camera/ultrasound imaging), rigorous semi-analytical mathematical models (lubrication, asymptotic and stability analysis models), and advanced computational fluid dynamics methods relying on open-source codes. Through engaging both graduate and undergraduate students, these highly qualified personnel trained in our research program experience a unique educational environment, designed for mathematical and experimental modeling of complex flows, i.e. a research area for which the demand for expertise and skills is increasing.