A framework for modeling flow over flexible submerged aquatic vegetation

沉水植物（SAV）在河流和河口过程中发挥着重要作用。通过减弱水流和调节水流湍流，SAV 可以提高沉积物稳定性，为众多重要物种提供食物和庇护所，并改善水质。因此，SAV 在自然栖息地和生物群落之间形成了重要的联系。灵活的 SAV 叶片与流场以及彼此之间以复杂但具有生态意义的方式相互作用。例如，高于临界流速阈值时，会发生连续的 SAV 冠层运动 (monami)，这与 SAV 上附着的藻类丰富度有关。迄今为止，我们对 SAV 结构如何影响流量衰减和质量传输的理解仍然有限，并且大多数观测工作、理论分析或建模研究中都没有明确包括植被叶片之间的物理相互作用。该项目将开发一个由现场观察和实验支持的综合建模框架。新模型将为工程师和自然资源管理者提供支持，他们的任务是制定法律规定的泉水恢复最低流量要求。该项目支持两名博士生，他们将接受水动力建模、水生生态学和数据分析方面的跨学科培训。将使用佛罗里达大学海岸实验室的便携式跑道水槽制定实践推广活动和 K-12 课程计划。这项研究的主要目标是量化植被结构特性和叶片间相互作用对流体动力学的影响，并表征不同流动条件下柔性植被冠层的集体行为。该研究开发了一种结构求解器，将软体动力学集成到有限元模型中，以研究植被叶片的变形和多个叶片之间的相互作用。该结构模型将与计算流体动力学模型相结合，以研究相互作用的水下柔性植被的流动。将在佛罗里达州多个泉水进行实地观测，其中测速仪和摄像机将收集流体动力学和植被冠层数据（例如有效植被高度和莫纳米特征）。该模型将通过观测数据进行验证，然后用于根据植被结构特性和流动条件识别不同的流动状态。该项目将利用观测数据和模型结果，开发一种改进的 SAV 对河流河段水动力影响的参数化方法，可在大规模建模框架中实施，以研究 SAV 对沉积物迁移和藻类生长动态等关键生态系统过程的影响。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Submerged aquatic vegetation (SAV) plays an important role in riverine and estuarine processes. By attenuating flow and modulating flow turbulence, SAV promotes sediment stability, provides food and shelter for numerous important species and improves water quality. SAV thus forms a critical link between physical habitat and biological communities. Flexible SAV blades interact with the flow field and with each other in complex, but ecologically significant ways. For example, above a critical flow velocity threshold, continuous SAV canopy motion (monami) occurs, which is associated with the abundance of attached algae on SAV. To date, our understanding of how SAV structure affects flow attenuation and mass transport is still limited, and physical interactions among vegetation blades are not included explicitly in most observational efforts, theoretical analyses or modeling studies. This project will develop an integrated modeling framework supported by field observations and experiments. The new model will support engineers and natural resources managers tasked with developing legally mandated minimum flow requirements for springs restoration. The project supports two PhD students, who will receive interdisciplinary training in hydrodynamic modeling, aquatic ecology, and data analysis. A hands-on outreach activity and K-12 lesson plan will be developed using a portable racetrack flume at the UF Coastal Lab.The primary goal of this study is to quantify the influence of vegetation structural properties and blade-to-blade interactions on hydrodynamics and characterize the collective behavior of flexible vegetation canopies under different flow conditions. The study develops a structural solver that integrates soft-body dynamics into a finite element model to investigate the deformation of vegetation blades and interactions between multiple blades. The structural model will be coupled with a computational fluid dynamics model to study flow over interacting submerged flexible vegetation. Field observations in multiple Florida springs will be carried out, in which velocimeters and video cameras will collect hydrodynamics and vegetation canopy data (such as effective vegetation heights and monami characteristics). The model will be validated with observational data, and then used to identify different flow regimes based on vegetation structural properties and flow conditions. This project will develop an improved parameterization of the effects of SAV on hydrodynamics on river reach-scale using observation data and model results, which can be implemented in large-scale modeling framework to study the effects of SAV on key ecosystem processes, such as sediment transport and algae growth dynamics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.