Elastic 'Ribbing' Instabilities in Fluid-Fluid Displacement Flows

流体-流体置换流中的弹性“罗纹”不稳定性

基本信息

批准号：
0089502
负责人：
Bamin Khomami
金额：
$ 18万
依托单位：
Washington University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2001
资助国家：
美国
起止时间：
2001-02-01 至 2005-01-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=0089502&HistoricalAwards=false
关键词：
Elastic Ribbing Instabilities Fluid Displacement

项目摘要

AbstractCTS-0089502B. Khomami, Washington UniversityThis is one of two identical proposals submitted by Washington University and Stanford University. A combined experimental and numerical study is proposed to examine the effect of elasticity on the stability of fluid-fluid displacement interfaces-sometimes known as the "ribbing" instability. Such instabilities limit either the speed or the quality of production of adhesive coatings in industrial processes. This is a collaborative effort between Bamin Khomami of Washington University and Eric Shaqfeh of Stanford University with the numerical part being carried out mainly in the former institution while the experimental part mainly at the latter institution. Preliminary experiments performed by the PI's showed the dramatic onset of such instabilities. It is hypothesized that the instability is caused by the unstable stress gradient created by the extensional finger flow near the displacing front. The research plan is to obtain quantitative experimental data of such instability flows using modern instrumentation, to carry out linear and nonlinear stability analysis of the flows, and full three-dimensional simulations of the unstable elastic fluid interfaces to test the hypothesis. In addition, the possibility of enhancing the stability of the system by introducing time-periodic parametric forcing will be examined by simulations.

Abstractcts-0089502b。华盛顿大学的霍马米（Khomami）是华盛顿大学和斯坦福大学提交的两个相同建议之一。提出了一项合并的实验和数值研究，以检查弹性对流体流体位移界面的稳定性的影响，后部是“肋骨”的不稳定性。这种不稳定性限制了工业过程中粘合剂涂料的速度或生产质量。这是华盛顿大学的Bamin Khomami与斯坦福大学的Eric Shaqfeh之间的合作努力，数值部分主要是在前机构进行的，而实验部分主要是在后者机构。 PI进行的初步实验显示了这种不稳定性的戏剧性发作。假设不稳定性是由位移前部附近的伸展手指流动产生的不稳定应力梯度引起的。研究计划是使用现代仪器来获得这种不稳定性流的定量实验数据，以对流量进行线性和非线性稳定性分析，并对不稳定的弹性流体界面进行完整的三维模拟，以检验假设。此外，通过仿真将检查通过引入时间周期性参数强迫来增强系统稳定性的可能性。