International Research Fellowship Program: Effects of Lift Forces and Turbulence on Bubble Motion

国际研究奖学金计划：升力和湍流对气泡运动的影响

• 批准号: 0401986
• 负责人: Woodrow Shew
• 金额: --
• 依托单位: Shew Woodrow L
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2008-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0401986&HistoricalAwards=false
• 关键词: International; Research; Fellowship; Program; Effects

0401986ShewThe International Research Fellowship Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a seventeen-month research fellowship by Dr. Woodrow L. Shew to work with Dr. Jean-Francois Pinton at Ecole Normale Superieure de Lyon in France.Gas-liquid flows play a crucial role in a diverse range of medical, industrial, and natural settings. In the medical setting, bubbles are known to enhance ultrasound imaging and show promise for controlled drug delivery and gene transfection. Air entrainment in turbulent ocean waves is critical for carbon sequestering and for the health of ocean ecosystems. Efficiency of boiling heat transfer and many chemical reactions depend upon bubble distribution and interaction with the fluid. Bubbles affect the hydrodynamics of ships and two-phase flow in gas/oil pipelines. Despite the large number of applications that would benefit, our understanding of how bubbles interact with complex fluid flows has significant gaps. A unique three-dimensional ultrasound technique provides observations of bubble behavior in a sequence of three flows: uniformly rotating laminar flow, a turbulent vortex, and fully developed turbulence. In each of these cases, the poorly understood lift forces and history effects influence the motion of the bubble. The lift force plays a role when vorticity is present in the flow and the history effects are due to interactions of the bubble with it's own wake. We study these effects on individual bubbles as well how they manifest in large-scale collective behavior of many bubbles. Connecting the small and large-scale behaviors is the primary goal of this research and is necessary to accurately model and predict bubbly flows in practical applications.

0401986SHEWTHE国际研究奖学金计划使美国科学家和工程师能够在国外进行三到二十四个月的研究。 The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a seventeen-month research fellowship by Dr. Woodrow L. Shew to work with Dr. Jean-Francois Pinton at Ecole Normale Superieure de Lyon in France.Gas-liquid flows play a crucial role in a diverse range of medical, industrial, and natural settings.在医疗环境中，已知气泡可以增强超声成像，并显示出对药物输送和基因转染的有望。湍流海浪中的空气夹带对于碳隔离和海洋生态系统的健康至关重要。沸腾传热和许多化学反应的效率取决于气泡分布和与流体的相互作用。气泡会影响船舶/油管道中的两相流动的流体动力。尽管有大量的应用将受益，但我们对气泡如何与复杂流体流相互作用的理解仍然存在很大的差距。独特的三维超声技术提供了三个流动序列的气泡行为的观察：均匀旋转的层流流，湍流涡流和完全开发的湍流。在每种情况下，鲜为人知的升力力和历史影响影响了气泡的运动。当流动中存在涡度时，升力力起着作用，历史效果是由于气泡与自身唤醒的相互作用所致。我们还研究了这些对单个气泡的影响，以及它们如何在许多气泡的大规模集体行为中表现出来。 连接小规模和大规模行为是这项研究的主要目标，对于准确地建模和预测实用应用中的气泡流是必要的。