Rayleigh-Taylor Instability, Non-Newtonian Rheology, and Chain Of Bubbles in Polymer Solutions

聚合物溶液中的瑞利-泰勒不稳定性、非牛顿流变学和气泡链

• 批准号: 0325743
• 负责人: Igor Kliakhandler
• 金额: $ 7万
• 依托单位: Michigan Technological University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-15 至 2006-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0325743&HistoricalAwards=false
• 关键词: Rayleigh; Taylor; Instability; Non; Newtonian

AbstractCTS-0325743I. Kliakhandler, Michigan Technological UniversityRayleigh-Tayler Instability, Non-Newtonian Rheology, and Chain of Bubbles in Polymer SolutionsThe motion of bubbles in a liquid is one of the major fields in hydrodynamics. It was studied already by Leonardo da Vinci, who noticed sinuous movement of rising bubbles, which is relatively easy to observe in long columns. The available body of knowledge and even its language connotation consider bubbles only as a discrete, detached from each other, units. The continuous jet of air in Newtonian liquids produces usual bubbling through Rayleigh-Taylor instability of the jet.In the recent work by PI it was found that in concentrated polymer solutions bubbles may form a qualitatively new structures. The development of Rayleigh-Taylor instability may be arrested by elastic properties of the polymer solutions. As a result, instead of individual bubbles, a long chain of bubbles is formed. The bubbles in the chain are very stable, slowly rising, connected by thin necks; the whole structure is similar to beads, or bubble "sausage"; see figures 1, 2 on the next pages. The rheological properties of polymeric solutions where it is possible to create the chain of bubble are quite interesting and call for their careful study.So far, even the general understanding of this unusual and interesting phenomenon is incomplete. Many basic questions about the chain of bubbles arise; no modeling of the phenomenon has yet been done.The proposed research will be devoted to the study and modeling of chain of bubbles dynamics, and will concentrate on the few main issues; rheology of polymers used in the formation of the chain, experimental elucidation of conditions necessary for the creation of chain of bubbles, analysis of stability of the air jet for various conditions, and strongly nonlinear modeling of the phenomenon.

摘要CTS-0325743 I。Kliakhandler，密歇根理工大学Rayleigh-Tayler不稳定性，非牛顿流变学和聚合物溶液中的气泡链气泡在液体中的运动是流体力学的主要领域之一。 列奥纳多达芬奇已经对此进行了研究，他注意到上升气泡的弯曲运动，这在长柱中相对容易观察到。 现有的知识体系，甚至其语言内涵都只把泡沫看作是一个离散的、彼此分离的单位。 空气在牛顿液体中的连续射流通过射流的Rayleigh-Taylor不稳定性产生通常的气泡。PI最近的工作发现，在浓缩的聚合物溶液中，气泡可能形成一种质的新结构。 Rayleigh-Taylor不稳定性的发展可以通过聚合物溶液的弹性性质来阻止。 结果，不是单个气泡，而是形成了一长串气泡。 链中的气泡非常稳定，缓慢上升，由细颈连接;整个结构类似于珠子，或气泡“香肠”;见下一页的图1，2。 聚合物溶液中气泡链的形成是一个非常有趣的现象，至今人们对这一现象的认识还很不全面。 许多关于气泡链的基本问题出现了，没有建模的现象还没有做。拟议的研究将致力于研究和建模的气泡链动力学，并将集中在几个主要问题;用于形成链的聚合物的流变学，产生气泡链所需条件的实验说明，各种条件下的空气射流的稳定性分析，以及该现象的强非线性建模。