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

2013年9月23日至12月20日，一个为期三个月的项目将在加州圣巴巴拉的Kavli理论物理研究所开展，该项目致力于研究地球物理流动中流体介导的粒子输运。该计划将提供一个机会，就必须解决的重要问题和需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。与该计划相关的是两个重点周和一个总结会议。人们对自然流体-颗粒流动的许多因素了解甚少。例如，在一定的颗粒浓度和颗粒-流体质量密度比范围内，湍流中非定常平均速度和波动速度对颗粒的影响；颗粒之间以及颗粒床表面颗粒与流体之间相互作用的性质；以及由水和风驱动的系统在河床上形成大规模特征的机制。在为期三个月的项目中，将举行两个重点周和一个结论性会议，该会议将包括未参加该项目的研究人员。一个重点周将致力于粒子与流体湍流的相互作用，另一个将集中在床上的侵蚀和沉积机制。结论性会议“自然中的粒子流动”将在该计划的最后一周举行，并试图提供对其主题的理解状态的概述。微粒流是自然发生的，在许多工业过程中也是如此。它们不像只涉及一种流体的流动那样为人所熟知。这是因为流体和粒子之间的相互作用以及流体中粒子之间的相互作用是复杂的，不容易用数学方法来描述。为了预测一些现象，如风沙形成的沙丘、威胁管道和通信电缆的水下雪崩、粉末和颗粒状雪的雪崩、火山爆发时熔岩中的火山灰和热气体或岩石的流动，努力实现这样的描述是很重要的。

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.