Collaborative Research: CROSSTEX - Wave Breaking and Boundary Layer Processes and the Resulting Sediment Suspension in the Surf zone

智力优势：CROS-Shore沉积物输送实验(Crosstex)项目是为了填补复杂的现场条件和小规模实验室实验之间的空白而开发的。本项目将侧重于近岸水动力和海浪带泥沙运动的物理机制，特别是波浪破碎湍流和底部边界层湍流对近岸泥沙悬浮过程的相对重要性。俄勒冈州立大学的大型波浪水槽是该项目的焦点，该项目结合了传统上在实验室实验、野外工作和数值模拟三个领域工作的研究人员的独特才华，并提供了一个促进近岸泥沙输运模拟科学水平的机会。预期成果之一是在空间和时间尺度上更好地了解与基于过程的模型有关的情况，以及一套用于验证数字模型的基准数据集。将结合用于测量水柱和边界层湍流应力的仪器的最新进展、基于网络的数据存档和检索以实现数据共享和协作的进展以及数字代码和计算机资源的最新实施。例如，仪器和实验技术将被组合成三个子阵列，用于观测三相流(瞬时速度、泥沙悬浮和空泡率)，每个子阵列重叠并聚焦于水柱的特定部分：表层、槽面以下和包括底部粗糙度的底部边界层。数值模拟将被分成三个子区域，以解决空间/时间尺度和不同复杂性(例如，单相流或两相流；湍流闭合方案的复杂性)的问题。广泛影响：波浪研究实验室(WRL)是美国国家科学基金会近岸科学和减灾(http://wave.oregonstate.edu/).)REU(本科生研究经验)站点考克斯博士是该网站的首席PI，另外两个Crosstex提案的3名合作PI担任教职员工导师。每年夏天，这些导师和他们的研究生与10名有才华的本科生一起进行积极的研究项目，总的目标是鼓励这些学生考虑研究生院。一半的REU学生来自代表性不足的群体，一半来自俄亥俄州立大学以外的地区。在这个项目的第一年和第二年，至少有5名REU学生将参与Crosstex项目。WRL积极参与K-12教育计划和外联活动，作为其指定为NSF-NEES站点的一部分。WRL目前正在与教育和外展人员和项目合作，以制定一个全面的K-12教育和外展计划，该计划将用于突出Crosstex项目。在这个为期四年的项目中，俄亥俄州立大学、俄亥俄州立大学和美国佛罗里达大学的几名研究生将接受复杂的实验和数值技术方面的培训。

Intellectual Merit: The CROs-Shore Sediment Transport EXperiment (CROSSTEX) project has been developed to fill in the gap between complex field conditions and small-scale laboratory experiments. This project will focus on the physical mechanisms of nearshore hydrodynamics and sediment transport in the surf zone and in particular the relative importance of wave breaking turbulence and bottom boundary layer turbulence on nearshore sediment suspension processes. The Large Wave Flume at Oregon State University serves as the focal point for this project, and the project combines the unique talents of researchers who have traditionally worked in the three areas of laboratory experiments, field work, and numerical modeling and provides an opportunity to advance the state of the science in nearshore modeling of sediment transport. One of the expected outcome is a better understanding at space- and time-scales relevant to process-based models and a set of benchmark data sets for validation of numerical models. The latest advances in instrumentation to measure turbulent stresses in the water column and boundary layer, advances in web-based data archival and retrieval for data sharing and collaboration, and the latest implementation of numerical codes and computer resources will be combined. For example, instrumentation and experimental techniques will be combined into three sub-arrays for observing three phase flow (instantaneous velocity, sediment suspension, and void fraction) with each overlapping and focusing on a particular part of the water column: the surface layer, below trough level, and the bottom boundary layer including bottom roughness. The numerical modeling will be divided into three sub-areas to resolve issues of space/time scales and varying in complexity (e.g., one- or two-phase flow; complexity of turbulence closure schemes).Broader Impacts: The Wave Research Laboratory (WRL) is an NSF REU (Research Experience for Undergraduates) site for nearshore science and hazard mitigation (http://wave.oregonstate.edu/). Dr. Cox is the lead PI for the site and 3 co-PIs on the two other CROSSTEX proposals serve as faculty mentors. Each summer, these mentors and their graduate students work with 10 talented undergraduate on active research projects with an overall goal of encouraging these students to consider graduate school. Half of the REU students are from under-represented groups, and half come from outside of OSU. For Years 1 and 2 of this project, at least 5 of the REU students will be involved in the CROSSTEX project. The WRL is actively engaged in K-12 educational programs and outreach as part of its designation as an NSF-NEES site. The WRL is currently working with education and outreach people and programs to develop a comprehensive K-12 education and outreach program which will be used to highlight the CROSSTEX project. During this four-year project, several graduate students at OSU, Ohio State, and U. Florida will receive training in sophisticated experimental and numerical techniques.