Support for US Participants and Phrasing Open Questions in the Kavli Program on Fluid-Particle Transport

1332328 PI：詹金斯一个为期三个月的计划，致力于流体介导的粒子输运在地球物理流动将发生在Kavli理论物理研究所在圣巴巴拉，加州，2013年9月23日至12月20日。该计划将提供一个机会，就必须解决的重要问题和要回答的关键问题达成共识，以促进对自然流体颗粒流动的理解。与该方案相关的是两个重点周和一个总结会议。自然界流体-颗粒流中有许多元素我们还知之甚少。例如，在一定的颗粒浓度和颗粒-流体质量密度比范围内的湍流中，不稳定的平均速度和脉动速度对颗粒的影响;颗粒之间以及颗粒与颗粒床表面的流体之间的相互作用的性质;以及在水和风驱动的系统中，大尺度特征在床上发展的机制。在为期三个月的计划中，将举行两个焦点周和一个总结会议，其中将涉及不参加该计划的研究人员。一个重点周将致力于颗粒与流体湍流的相互作用，另一个将集中在床的侵蚀和沉积的机制。最后一个讲座，“自然界中的粒子流”，将在课程的最后一周举行，并试图提供对其主题的理解状态的概述。粒子流在自然界和许多工业过程中发生。它们不像只涉及流体的流动那样容易理解.这是因为流体与颗粒之间的相互作用以及流体中颗粒之间的相互作用是复杂的，并且不容易用数学描述。为了预测风吹沙形成沙丘、威胁管道和通信电缆的水下雪崩、粉末和颗粒雪的雪崩以及火山爆发期间火山灰和热气或熔岩中的岩石流动等现象，必须设法实现这种描述。

1332328PI: JenkinsA three-month long program devoted to fluid-mediated particle transport in geophysical flows will take place at the Kavli Institute for Theoretical Physics in Santa Barbara, California, between September 23 and December 20, 2013. This program will provide an opportunity to develop a consensus regarding the important issues that must be addressed and the key questions to be answered in order to advance the understanding of natural fluid-particle flows. Associated with the program are two focus weeks and a concluding conference. There are many elements of natural fluid-particle flows that are poorly understood. Examples are the in-fluence of the unsteady mean and fluctuating velocities on particles in a turbulent flow over a range of particle concentration and ratios of particle-fluid mass density; the nature of the inter-actions between particles and between the particles and fluid at the surface of a particle bed; and the mechanisms by which large-scale features develop on the bed in systems driven by water and the wind. Within the three-month program, two focus weeks and a concluding conference will take place that will involve researchers not attending the program. One focus week will be devoted to the interactions of particles with fluid turblence, the other will concentrate on mechanisms of erosion and deposition at the bed. The concluding confence, "Particle-Laden Flows in Nature", will take place during the last week of the program and attempt to provide an overview of the state of understanding of its subject.Particle-laden flows occur naturally and in many industrial processes. They are not so well understood as flows involving only a fluid. This is because the interaction between the fluid and the particles and those between particles in the fluid are complicated and not easy to describe mathematically. It is important to try to achieve such descriptions in order to predict phenomena such as dune formation by wind-blown sand, underwater avalanches that threaten pipeline and communications cables, avalanches of powder and granular snow, and flows of ash and hot gases or rocks in molten lava during volcanic eruptions.