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

研究人员和他们的同事研究了仅在界面上出现的由材料复杂性驱动的流体中的新型不稳定性。例如，当两个反应胶束液体接触时，反应可能会在界面上产生越来越大的凝胶状相，这显著地加强了流体之间的边界。另一个例子是纳米胶体粒子的存在，这些胶体粒子聚集在界面上。胶体间力还赋予界面以刚性，甚至可能在足够高的体积分数时堵塞界面。这项提议的目标是为这些非常困难的问题开发全面的、物理上合适的模型和模拟。这些问题的高度非线性性质使得快速、准确和健壮的数值方法对它们的研究至关重要。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，并开发控制其图案形成能力的策略，方法是：(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、数值和建模研究；(3)进行实验，以校准和验证数学模型，检验模型预测，并帮助阐明潜在的物理过程。当驱动力与阻力相互竞争时，界面不稳定，结果是形成复杂的图案。例子出现在不同的系统中，例如丝状微生物、不断生长的生物膜、阴燃的火焰前锋和熔岩流。这个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。将进行实验以验证模型和测试模型预测，并帮助阐明潜在的物理过程。这项研究将集中在具有复杂界面物理的流动，如反应和界面上的纳米颗粒。研究活动将提供新的综合的理论、数值和实验结果，可用于(1)进一步探索这些被驱使失去平衡的图案形成系统；(2)制定控制演变形态的指导方针。虽然这里研究的是具体和新颖的应用，但新的数学和自适应数值技术有望在目前的上下文之外得到应用。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，并计划为初中生和本科生(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)提供外展方案。安装技术人员)。

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.).