CAREER: High Resolution Particle Tracking in Granular and Turbulent Fluid Flows

*非技术摘要*这个学院早期职业生涯奖支持一个测量湍流和颗粒流中粒子轨迹的项目。将开发一种结合立体高速成像和实时图像处理的新系统来跟踪颗粒。该系统与人类视觉系统跟踪物体的方式有许多相似之处，具有广泛的应用潜力。预计这些研究将有助于解决关键问题，如湍流轨迹如何取决于产生水流的方法，以及沉积物如何在湍流中传输。高速成像也将被用来测量流动颗粒中发生的快速变化。颗粒材料可以在颗粒之间多次碰撞的类流体状态和没有颗粒运动的静止堆积之间快速转换。这些研究将指导人们寻找对这些转变的更好描述。这些结果将对农业和采矿业等广泛使用颗粒状材料的行业产生兴趣。将开展两项教育和外展活动。卫斯理大学将开设量子力学和经典力学的高级本科课程，强调学生通过实验活动积极参与学习。通过与PIMMS(增加数学和科学掌握项目)的合作，该教员将培训城市学区的小学教师掌握他们教给学生的物理科学单元的内容。该项目由材料研究部门(凝聚态物理)和化学运输系统部门(颗粒和多相过程)共同资助。*技术摘要*该学院早期职业生涯奖支持一个项目，该项目旨在通过高分辨率光学粒子跟踪测量来发展我们对湍流和颗粒流的动力学理解。该项目将开发一种新的成像设计，使用立体高速成像和实时图像处理来获取湍流中平流粒子的3D轨迹。这些研究将有助于解决关于湍流轨迹的普遍性和湍流中大而非中性浮力粒子的运动的关键问题。在颗粒流中，精确的粒子跟踪将允许对依赖于时间的统计场进行新的测量。在振动流态化的准2D颗粒气体中进行的重力崩塌测量将为流体力学近似如何开始失效提供关键测试。此外，还将开展两项教育和外联举措。卫斯理大学将开设量子力学和经典力学的高级本科课程，强调学生通过实验活动积极参与学习。通过与PIMMS(增加数学和科学掌握项目)的合作，PI将培训城市学区的小学教师掌握他们教给学生的物理单元的内容。该项目由材料研究司(凝聚态物理)和化学运输系统司(颗粒和多相过程)共同资助。

*******NON-TECHNICAL ABSTRACT*******This Faculty Early Career award supports a project to measure particle trajectories in turbulent fluids and granular flows. A novel system combining stereoscopic high speed imaging with real-time image processing will be developed to track the particles. This system has many similarities to the way the human visual system tracks objects, and it has potential for broad application. The studies are expected to help resolve key questions such as how turbulent trajectories depend on the method of creating the flow and how sediments are transported in turbulence. High-speed imaging will also be used to measure the rapid changes that occur in flowing grains. Granular materials can quickly transition between a fluid-like state with many collisions between particles and a stationary pile with no particle motion. The studies will guide the search for a better description of these transitions. These results would be of interest to industries such as agriculture and mining, where granular materials are widely used. Two educational and outreach initiatives will be pursued. Upper level undergraduate courses in quantum and classical mechanics, emphasizing the active engagement of students in learning through experimental activities, will be developed at Wesleyan University. Through a partnership with PIMMS (Project to Increase Mastery of Mathematics and Science), the faculty member will train elementary teachers in urban school districts in mastering the content of the physical science units they teach to their students. This project is co-funded by the Division of Materials Research (Condensed Matter Physics) and the Division of Chemical Transport Systems (Particulate and Multiphase Processes).********TECHNICAL ABSTRACT*****This Faculty Early Career award supports a project to develop our dynamical understanding of turbulent and granular flows through high-resolution optical particle tracking measurements. The project will develop a novel imaging design that uses stereoscopic high-speed imaging and real-time image processing to acquire 3D trajectories of particles advected in turbulent fluid flow. These studies will help resolve key questions about the universality of turbulent trajectories and the motion of large and non-neutrally buoyant particles in turbulent flows. In granular flows, precision particle tracking will allow new measurements of time-dependent statistical fields. Measurements in a vibrofluidized quasi-2D granular gas undergoing gravitational collapse will provide critical tests of how hydrodynamic approximations begin to fail. In addition two educational and outreach initiatives will be pursued. Upper level undergraduate courses in quantum and classical mechanics, emphasizing the active engagement of students in learning through experimental activities, will be developed at Wesleyan University. Through a partnership with PIMMS (Project to Increase Mastery of Mathematics and Science), the PI will train elementary teachers in urban school districts in mastering the content of the physical science units they teach to their students. This project is co-funded by the Division of Materials Research (Condensed Matter Physics) and the Division of Chemical Transport Systems (Particulate and Multiphase Processes).