Transport Processes in Two-Phase Macroscopically Homogeneous Systems

9318820 Acrivos该项目涉及两相、宏观均匀材料中传输过程的理论研究。各种分析和数值技术被用来扩展P.I.的无限稀释悬浮液的浓缩悬浮液和扩展他们的工作的剪切诱导的纵向和横向的自扩散率的颗粒的剪切诱导的梯度扩散率。这项工作可能会导致在悬浮液中的扩散运输领域的根本性进展，因为它从基本的，简化的，渐近的理论极限的情况下走向更复杂的系统中的潜在应用所在。由于所提出的研究的非常基本的性质，有许多潜在的应用。潜在的应用范围包括沉降、在非均匀剪切流中形成堵塞物和沉降颗粒的再悬浮、通过热泳在接近失重的条件下从液体中分离气泡（在太空中生产超高纯度材料）、以及预测两相介质中的有效热导率、渗透率和其他传输特性。确定复合材料有效性能的有效介质技术将有更坚实的理论基础，并将发展计算流动悬浮液中颗粒分布函数的动力学模型。本项目的理论研究将与P.I.的实验计划（由美国国防部资助）。的能量）和来自文献的数据将被用来检验理论结果。***

9318820 Acrivos This project involves the theoretical study of transport processes in two-phase, macroscopically homogenous materials. A variety of analytical and numerical techniques are used to extend the prior work of the P.I.'s on infinitely dilute suspensions to concentrated suspensions and to extend their work on the shear-induced longitudinal and transverse self-diffusivity of particles to the shear-induced gradient diffusivity. This work may lead to fundamental advances in the field of diffusive transport in suspensions because it moves from the basic, simplified, and asymptotic theoretical limiting cases toward the more complex systems in which the potential applications lie. There are many potential applications because of the very fundamental nature of the proposed study. The range of potential applications includes sedimentation, formation of plugs in non-homogeneous shear flow and the re-suspension of settled particles, separation of gas bubbles from liquids under near weightless conditions (production of ultra high purity materials in space) by thermophoresis, and prediction of effective thermal conductivity, permeability, and other transport properties in two-phase media. The effective medium technique for determining the effective properties of composite materials will be put on a firmer theoretical foundation and a kinetic model for computing particle distribution functions in flowing suspensions will be developed. The theoretical studies in this project will be coordinated with the P.I.'s experimental program (funded through U.S. Dept. of Energy) and the data form the literature will be used to test the theoretical results. ***