The Impact of Blade Motion on the Flux to a Blade Surface

淡水和咸水系统中的水生植被每年提供价值超过1万亿美元的生态系统服务。海草和淡水大型植物通过从水中过滤营养物质，减少再悬浮，并在停滞区产生氧气来改善水质。与陆生植物不同，水生植物通过根部获取营养，而水生植物通过叶子和叶片从周围的水中获取必要的营养。养分的吸收控制着植被的生长和健康，以及它对水质的潜在影响。拟议的研究将研究水动力条件和单个叶片的运动如何影响养分流向植物的速率，目的是更好地预测潜在的最大吸收速率。该项目将研究单个叶片与单向水流和前进波的相互作用，以了解叶片运动如何影响叶片表面的流量。模型叶片将由低密度聚乙烯(LDPE)建造，低密度聚乙烯优先吸收我们的水槽水中存在的有机化合物(例如氯仿)。由于其高分配系数，在暴露的最初阶段，LDPE刀片吸收化学物质的速度与其传递到表面的速度一样快，模拟了质量传输限制吸收。这个项目将把现有的固体边界通量模型扩展到与水生植物相关的条件下，特别是引入叶片运动和波浪条件的影响。它将有助于对与化学和生物工程相关的灵活边界上的质量交换的基本理解。

Aquatic vegetation in fresh- and salt-water systems provides ecosystem services valued at over one trillion dollars per year. Seagrass and freshwater macrophytes enhance water quality by filtering nutrients from the water, reducing re-suspension, and producing oxygen in stagnant regions. Unlike terrestrial plants, which acquire nutrients through their roots, aquatic plants acquire essential nutrients through their leaves and blades from the surrounding water. The nutrient uptake controls the growth and health of the vegetation, as well as its potential impact on water quality. The proposed research will examine how the hydrodynamic conditions and the motion of individual blades impacts the rate of nutrient flux to the plant, with the goal of providing better predictions of the potential maximum uptake rate. The project will examine the interaction of individual blades with uni-directional current and progressive waves to understand how blade motion influences flux to the blade surface. The model blades will be constructed from low-density polyethylene (LDPE), which preferentially absorb the organic compounds present in our flume water (e.g. chloroform). Because of its high partitioning coefficient, for an initial period of exposure, the LDPE blade takes in chemicals as fast as it can be delivered to the surface, mimicking mass-transport limiting uptake. This project will extend existing models for flux at solid boundaries to conditions relevant to macrophytes, specifically introducing the impact of blade motion and conditions with waves. It will contribute a basic understanding of mass exchange at flexible boundaries that is relevant to chemical and biological engineering.