Unsteady hydrodynamic conditions and biological/biogeochemical processes

我的研究计划的长期目标是了解流体动力学因素如何影响生物和地球化学相关的质量运输（即，质量的运动）。环境流动是湍流，其特点是底栖生物（底部区域）中流动和流体-结构相互作用的变化造成的不稳定流动条件，难以在实验室中重现，也难以建立数学模型。因此，在实验室和/或计算模型中通常使用简化的良好行为和理想化的水动力条件。该建议旨在更好地理解非稳态条件如何影响溶解的物质的传质（例如，气体和营养物）和颗粒（例如，藻类和配子）在水生系统中的作用;它将通过实验室，现场和计算实验来实现。结果将有利于物理和自然科学，因为我将研究流体力学和生态生理学的生物体/系统使用跨学科的方法。最终，从这些结果中获得的见解将更普遍地应用于实验室，并被纳入模型和用于计算研究。由流动变化、扰动、不稳定性和流体-结构相互作用（涡激振动; VIV）引起的不稳定流动影响质量的输送和使用该物质的生物体。拟议的研究将促进我们对不稳定条件如何影响大型植物吸收溶解物质的理解（即，水生植物），结构上颗粒的捕获，以及贻贝对颗粒物质的清除（即，悬浮物喂养），以及水生系统的底栖和潜流区发生的生物地球化学通量。我建议的研究将集中在传质的基本机制和理论结构，以更好地了解它是如何发生在这些系统中。 在接下来的五年里，我的具体目标是确定非稳定流如何影响：（1）水生植物对溶解无机碳的吸收，有和没有VIV引起的振荡;（2）流动室中淡水贻贝的悬浮物摄食率和现场的底栖-浮游耦合;（3）悬浮物的命运（例如，颗粒、藻类、幼虫）在粗糙湍流边界中传输，其中粗糙度导致场的不稳定条件;以及（4）环境相关标量的传输（例如，氧气、温度）与沉积物和潜流带的相互作用。这些主题是相互联系的，因为它们是我的长期目标的组成部分，以了解流体动力学因素如何影响环境质量运输。 重要的是，解决这些主题将导致更好地了解水生生态系统的生产力和功能，这对水质，保护，渔业和气候变化具有重要意义。

The long-term objective of my research program is to understand how hydrodynamic factors affect biologically and biogeochemically relevant mass transport (i.e., the movement of mass) in the environment. Environmental flows are turbulent and are characterized by unsteady flow conditions caused by variations in flow and fluid-structure interactions in the benthos (bottom region), which are difficult to reproduce in the laboratory and to model mathematically. Consequently, simplified well-behaved and idealized hydrodynamic conditions are typically used in laboratory and/or computational models. This proposal is directed toward a better understanding of how unsteady conditions affect the mass transport of dissolved (e.g., gases and nutrients) and particulate (e.g., algae, and gametes) matter in aquatic systems; it will be achieved through laboratory, field, and computational experiments. Results will benefit the physical and natural sciences because I will examine both the hydrodynamics and the ecophysiology of the organism/system using an interdisciplinary approach. Ultimately insights from these results will be applied more commonly in laboratory as well as be incorporated into models and used in computational studies. Unsteady flows, caused by changes in flow, disturbances, instabilities and by fluid-structure interactions (vortex-induced vibration; VIV), affect the transport of mass and the organisms using the matter. The proposed research will advance our understanding of how unsteady conditions affect the uptake of dissolved matter in macrophytes (i.e., aquatic plants), the capture of particulates on structures, and particulate matter clearance by mussels (i.e., suspension feeding), as well as biogeochemical flux that occur in the benthic and hyporheic zones of aquatic systems. My proposed research will focus on the fundamental mechanisms and theoretical constructs underlying mass transfer to better understand how it occurs in these systems. My specific objective over the next five years is to determine how unsteady flow affects: (1) the uptake of dissolved inorganic carbon by aquatic macrophytes with and without oscillations caused by VIV; (2) suspension feeding rates in freshwater mussels in flow chambers and benthic-pelagic coupling in the field; (3) the fate of suspended matter (e.g., particles, algae, larvae) transported in rough-turbulent boundaries in which roughness leads to unsteady conditions the field; and (4) the transport of environmentally relevant scalars (e.g., oxygen, temperature) to and from sediments and hyporheic zones in the field. These themes are linked because they are components of my long-term objective to understand how hydrodynamic factors affect environmental mass transport.  Importantly, addressing these themes will lead to a better understanding of the productivity and functioning of aquatic ecosystems, which has important implications to water quality, conservation, fisheries, and climate change.