Collaborative Research: Efficient transport of bubbles and drops

摘要项目编号：0626123和0626070主要研究人员：Singh， Pushpendra和Aubry， nadine联系单位：基金会@NJIT和卡内基梅隆大学项目名称：合作研究：气泡和液滴的有效传输智力优势：提出了一种结合模拟、分析和实验的方法来理解导致气泡在粘弹性液体中上升速度增加几倍的机制，这种机制发生在气泡体积的临界值上。将研究气泡速度和粘弹性应力的瞬态发展，以及它们与气泡尾端尖状形状的关系。还将探讨在微流体装置中使用这种现象在粘弹性介质中有效输送液滴的可能性，例如用于高通量筛选生物测定。粘弹性液体中流动引起的应力会导致不稳定性，这可能会极大地改变通常的牛顿“溶液”，并导致新的溶液。在上升气泡的情况下，对于某些参数值，存在一个临界气泡体积，在此体积之上，流量被修改，因此阻力系数与稍小气泡的值相比降低了一个数量级。更广泛的影响：这项研究将与教育充分结合，研究生和本科生，特别是妇女和代表性不足的少数民族的参与。参与的学生将学习新的，最先进的CFD，分析和实验技术来分析复杂的多相流。反过来，研究成果将被纳入pi教授的流体力学课程中，以说明(i)牛顿流体和非牛顿流体在行为上的差异，以及（ii）如何在应用中利用这种差异。拟议的研究将加强对基础和工业重要性的复杂多相流的最新理解，有可能(i)对许多遇到泡沫，乳液和血细胞，DNA，蛋白质操作的工业过程产生影响，以及（ii）导致高效微流体运输的新技术。它将通过扩大工具箱来研究多尺度和多物理场现象，通过产生创新技术，通过鼓励妇女和代表性不足的少数群体参与科学和技术，以及通过教育公众了解令人兴奋的科学研究和技术创新，使社会受益。

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.