Simulations of surface tension driven flows and interactions between fluid flow and solid particles

这一建议侧重于多相流。该项目的第一部分是研究流体-流体界面，在小尺度上，由表面张力主导。这种流动与乳剂、气泡、液滴和微流体装置的动力学有关。高度精确的数值模拟将用于描述液滴合并或强制通过微管的动力学。将提出一种直接模拟空间变化表面张力的新方法。模拟将用于探索马兰戈尼流在微滴中产生混合的潜力。该项目的第二部分关注的是小固体颗粒与其周围流体之间的相互作用，这在各种自然系统（如河流、海洋和大气）中是决定性的。数值模拟将探讨微粒物质被上覆流体侵蚀的机制。沉降颗粒以平流而非扩散的方式传递热量，而不产生大规模流体运动的能力也将被检验。总体目标是开发工具来研究这些复杂的物理系统，并对多相流中的基本现象有一个基本的了解。本提案中描述的研究将在加州大学最新的校区默塞德进行（2005年开放）。它是中央山谷唯一的研究型大学，学生群体既多样化，又传统上在大学层面上代表性不足。该项目将为本科生和研究生提供研究机会。研究的第一个主题涉及液体和气体与其他液体的相互作用，就像水滴和气泡的情况一样。将特别强调在温度变化的情况下获得液滴行为的理解。实验室——芯片?可以在微米尺度上研究受控反应的系统。第二个研究领域将是流体与小固体颗粒（如沙子和沉积物）的相互作用。流体流动侵蚀沉积颗粒的机制以及沉降颗粒影响热传递的能力将被详细研究。将开发广泛适用的新技术来准确有效地模拟这些系统。

This proposal focuses on multiphase flows. The first part of the project is a study of fluid-fluid interfaces which, on small scales, are dominated by surface tension. Such flows are relevant to the dynamics of emulsions, bubbles, drops and micro-fluidic devices. Highly accurate numerical simulations will be employed to describe the dynamics of drops merging or forced through micro-pipes. A novel approach to direct simulations of spatially varying surface tension will be presented. The simulations will be used to explore the potential of Marangoni flows to generate mixing in micro-drops. The second part of the project is concerned with interactions between small solid particles and their surrounding fluid, which are determinant in a variety of natural systems such as rivers, oceans, and the atmosphere. Numerical simulations will explore the mechanism by which particulate matter is eroded by an overlying fluid. The capacity of settling particles to transport heat in an advective rather than diffusive manner, without generating large scale fluid motion, will also be examined. The overall goal is to develop tools to investigate these complex physical systems and extract a fundamental understanding of basic phenomena at play in multiphase flows.The research described in this proposal will be conducted at Merced, the newest campus (opened in 2005) of the University of California. It is the only research university of the Central Valley, and the student body is both diverse and traditionally under-represented at the university level. This project will provide research opportunities to both undergraduate and graduate students. The first topic studied involves the interaction of liquids and gases with other liquids, as is the case in drops and bubbles. Special emphasis will be placed on obtaining an understanding of the behavior of drops in the presence of temperature variations in ?lab-on-a- chip? systems, which allow controlled reactions to be studied on the micron scale. A second field of study will be the interaction of fluids with small solid particles, such as sand and sediments. The mechanism by which fluid flow can erode deposited particles, and the capacity of settling particles to affect heat transport will be investigated in detail. Broadly applicable new techniques will be developed to simulated these systems accurately and efficiently.