Collaborative Research: Efficient transport of bubbles and drops

摘要提案编号：0626123和0626070主要研究者：辛格，Pushpendra和Aubry，Nadine附属机构：NJIT基金会和梅尔基-梅隆大学提案标题：合作研究：气泡和液滴的有效运输智力优点：提出了一种结合模拟，分析和实验的方法，以了解导致气泡在粘弹性液体中上升的速度增加几倍的机制，该机制发生在气泡体积的临界值。气泡速度和粘弹性应力的瞬态发展，以及它们对气泡尾端的尖点形状的依赖性，将被研究。在微流体装置中使用这种现象以在粘弹性介质中有效地输送液滴的可能性，用于高通量筛选生物测定，也将进行探索。粘弹性液体中的流动诱导应力会引起不稳定性，从而可能极大地改变通常的牛顿解并导致新的解。在上升气泡的情况下，对于某些参数值，存在临界气泡体积，在该临界气泡体积以上，流动被修改，使得阻力系数与其对于稍微小的气泡的值相比减小一个数量级。更广泛的影响：这项研究将与教育充分结合，让研究生和本科生，特别是妇女和代表性不足的少数民族参与。参与的学生将学习新的，最先进的CFD，分析和实验技术，用于分析复杂的多相流。研究结果，反过来，将被纳入流体力学课程的PI教，以说明（一）牛顿和非牛顿流体的行为的差异和（ii）如何在应用中利用这种差异。拟议的研究将增强对具有基础和工业重要性的复杂多相流的最新理解，有可能（i）对许多工业过程产生影响，这些过程遇到泡沫，乳液和操纵血细胞，DNA，蛋白质，以及（ii）导致有效的微流体运输的新技术。它将通过以下方式造福社会：扩大研究多尺度和多物理现象的工具箱，产生创新技术，鼓励妇女和代表性不足的少数群体参与科学和技术，教育公众了解令人兴奋的科学研究和技术创新。

ABSTRACTProposal Numbers: 0626123 and 0626070Principal Investigators: Singh, Pushpendra and Aubry, NadineAffiliations: Foundation @NJIT and Carnegie-Mellon UniversityProposal Title: Collaborative Research: Efficient transport of bubbles and dropsIntellectual Merit:An approach combining simulation, analysis and experiments is proposed to understand the mechanism that leads to a several-fold increase in the velocity of bubbles rising in viscoelastic liquids that occurs at a critical value of the bubble volume. The transient development of the bubble velocity and viscoelastic stresses, and their dependence on the cusp-like shape of the bubble's trailing end, will be investigated. The possibility of using this phenomenon in microfluidic devices to efficiently transport droplets in viscoelastic media, e.g., for high-throughput screening bioassays, will also be explored. The flow-induced stresses in viscoelastic liquids can cause instabilities that may drastically modify the usual Newtonian" solution and lead to a new solution. In the case of a rising bubble, for some parameter values, there is a critical bubble volume above which the flow is modified so that the drag coefficient is reduced by an order of magnitude compared to its value for slightly smaller bubbles. Broader Impacts: This research will be fully integrated with education, with the involvement of graduate and undergraduate students, particularly women and underrepresented minorities. The students involved will learn new, state-of-the-art CFD, analytical and experimental techniques for analyzing complex multiphase flows. Research results, in turn, will be incorporated in the fluid mechanics courses the PIs teach to illustrate (i) the difference in behavior of Newtonian and non- Newtonian fluids and (ii) how such differences can be exploited in applications. The proposed research will enhance the state-of-the-art understanding of complex multiphase flows of fundamental and industrial importance, with the potential to (i) have an impact on many industrial processes which encounter foams, emulsions, and manipulation of blood cells, DNA, proteins, as well as (ii) lead to novel techniques for efficient microfluidic transport. It will benefit society by expanding the toolbox to study multiscale and multiphysics phenomena, by resulting in innovative technologies, by encouraging the participation of women and under-represented minorities in science and technology, and by educating the public about exciting scientific research and technology innovations.