Light Scattering Studies in Fluids

流体中的光散射研究

• 批准号: 9217494
• 负责人: Walter Goldburg
• 金额: $ 42万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-02-15 至 1996-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9217494&HistoricalAwards=false
• 关键词: Light; Scattering; Studies; Fluids

It is proposed to study small-scale velocity differences in open and closed turbulent flows. Of special interest is the cross-over from the chaotic state (few degrees of freedom) to the fully turbulent state, where "cascade" ideas of turbulence may be applied. The turbulence will be probed by conventional techniques, such as laser Doppler velocimetry, and also by homodyne light scattering, which permits the measurement of velocity differences without making the "frozen-turbulence" assumption. Also to be studied are: the dynamics of phase-separation of fluids and liquid crystals contained in porous media; and nucleation in fluid mixtures under uniform shear. The common thread running through all of this work is that of systems driven far from equilibrium. %%% The research deals with "self-similar" phenomena which have the property that they look the same when viewed on all scales of magnification. Turbulent fluids exhibit this self-similarity, which will be studied by light scattering. Another self-similar occurrence is the motion of fluids constrained within porous media (e.g., oil in sand). The goal is to understand the origin of this self-similarity.

建议在开阔地研究小尺度速度差， 封闭的湍流 特别有趣的是交叉 从混沌状态（几个自由度）到完全 湍流状态，其中湍流的“级联”概念可能是 应用。 湍流将通过常规技术进行探测， 例如激光多普勒测速法，也可以通过零差光 散射，它允许测量速度差 而不做“冻结湍流”假设。 还要 研究的是：流体和液体的相分离动力学 多孔介质中包含的晶体;和流体中的成核 均匀剪切下的混合物。 贯穿于我们生活中的 所有这些工作都是远离平衡的系统的工作。 %%% 这项研究涉及的是“自相似”现象， 它们在所有尺度上看起来都是一样的， 倍率 湍流表现出这种自相似性， 这将通过光散射来研究。 另一个自相似 产状是受多孔介质约束的流体的运动 (e.g.,砂中的油）。 我们的目标是了解这一现象的起源 自相似性