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

叶片运动对叶片表面通量的影响

• 批准号: 1140970
• 负责人: Heidi Nepf
• 金额: $ 37.32万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-15 至 2017-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1140970&HistoricalAwards=false
• 关键词: Impact; Blade; Motion; Flux; Surface

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.

新鲜和盐水系统中的水生植被提供每年价值超过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，减少重新悬浮并在停滞的地区产生氧气来提高水质。 与陆地植物通过其根源获取营养的植物不同，水生植物通过其叶子和叶片从周围水中获取必需的营养。 营养摄取控制植被的生长和健康及其对水质的潜在影响。 拟议的研究将研究流体动力条件和单个叶片的运动如何影响植物营养通量的速率，以便更好地预测潜在的最大摄取速率。 该项目将检查单个叶片与单向电流和渐进波的相互作用，以了解叶片运动如何影响叶片表面的通量。 模型叶片将由低密度聚乙烯（LDPE）构建，该聚乙烯优先吸收了水槽水中存在的有机化合物（例如氯仿）。 由于其较高的分配系数，在最初的暴露期间，LDPE刀片将化学品采用的速度和可以传递到表面的速度，从而模仿了质量传输的限制吸收。该项目将将现有在固体边界的通量模型扩展到与大型植物相关的条件，特别是引入了叶片运动和条件的影响。 它将在柔性边界上对质量交流的基本了解，这与化学和生物工程有关。