Collaborative Research: Reactive instabilities, colloids and interfacial flows: Experiments, models and numerics

研究人员及其同事研究了仅在界面处发生的材料复杂性驱动的流体中的新型不稳定性。例如，当使两种反应胶束液体接触时，反应可在界面处产生生长的凝胶状相，这显著地使流体之间的边界变硬。 另一个例子来自于在界面处积累的纳米级胶体颗粒的存在。胶体间力还赋予界面刚度，并且甚至可以在足够高的体积分数下堵塞界面。该提案的目标是为这些非常困难的问题开发全面的、物理上适当的模型和模拟。这些问题的高度非线性性质使得快速，准确和强大的数值方法对他们的研究至关重要。该研究小组计划研究具有复杂物理性质的界面的非线性动力学，并通过以下方法开发控制其模式形成能力的策略：（1）开发和应用最先进的自适应数值方法进行大规模计算;（2）对重要的组成过程进行分析，数值和模拟研究;以及（3）进行实验以校准和验证数学模型，以测试模型预测，并帮助阐明潜在的物理过程。当驱动力与阻力竞争时，界面不稳定性发生，其结果是形成复杂图案。例子发生在不同的系统，如包括寄生微生物，生长的生物膜，阴燃火焰前锋，熔岩流。该项目的目标是开发全面的，物理上合适的模型和有效的数值方法来解决这些问题。实验将进行验证模型和测试模型的预测，并帮助阐明潜在的物理过程。研究将集中在具有复杂界面物理的流动，如界面处的反应和纳米级颗粒。研究活动将提供新的综合理论，数值和实验结果，可用于（1）进一步探索这些模式形成系统被赶出平衡;（2）制定控制不断演变的形态的指导方针。虽然具体的和新的应用程序进行了研究，在这里，新的数学和自适应数值技术预计有超出本上下文中的应用。 此外，该项目将为年轻研究人员提供宝贵的跨学科培训机会，并计划为中学生和本科生（宾夕法尼亚州立大学），高中生（加州大学欧文分校）和本科生（伊利诺伊州）提供外展计划。Inst. Techn.）。

The investigators and their colleagues study novel instabilities in fluids driven by material complexity occurring only at interfaces. For instance, when two reacting micellar liquids are brought into contact, the reaction may produce a growing gel-like phase at the interface, which significantly stiffens the boundary between the fluids. Another example arises from the presence of nanoscale colloidal particles which accumulate at interfaces. Intercolloid forces also endow the interface with stiffness, and may even jam the interface at sufficiently high volume fraction. The goal of this proposal is to develop comprehensive, physically appropriate models and simulations for these very difficult problems. The highly nonlinear nature of these problems makes fast, accurate and robust numerical methods essential to their study. The research team plans to investigate the nonlinear dynamics of interfaces endowed with complex physical properties and to develop strategies to control their pattern forming abilities by (1) developing and applying state-of-the-art adaptive numerical methods to large-scale computation; (2) performing analytical, numerical and modeling studies of important constituent processes; and (3) performing experiments to calibrate and validate the mathematical models, to test the model predictions, and to help elucidate the underlying physical processes.Interfacial instabilities occur when driving forces compete with resistive forces with a consequence being the formation of complex patterns. Examples occur in diverse systems such as including filamentary microorganisms, growing biofilms, smoldering flame fronts, and lava flows. The goal of this project is to develop comprehensive, physically appropriate models and efficient numerical methods for solving such problems. Experiments will be performed to validate the models and test the model predictions, and to help elucidate the underlying physical processes. The research will focus on flows with complex interfacial physics such as reactions and nanoscale particles at interfaces. The research activities will provide new integrated theoretical, numerical and experimental results that can be used to (1) further explore these pattern forming systems that are driven out of equilibrium; (2)develop guidelines for controlling the evolving morphologies. While specific and novel applications are investigated here, the new mathematical and adaptive numerical techniques are expected have application beyond the present context. In addition, this project will provide valuable interdisciplinary training opportunities for young researchers, and outreach programs are planned for middle school and undergraduate students (Penn State), high school students (UC Irvine) and undergraduate students (Ill. Inst. Techn.).