ISS: Quantifying Cohesive Sediment Dynamics for Advanced Environmental Modeling

PI：Luzzatto-Fegiz，Paolo提案编号：1638156拟议的研究重点是研究倾向于聚集的粒子之间的力。物理系统是石英和粘土颗粒的感情。在国际空间站（ISS）进行实验的优点是，可以将作用在颗粒上的力分为短程（粘附力）和长程（凝聚力），因为人们可以在很长的时间尺度上观察集群动态，而不会出现重力沉降，这使得在地球上进行实验时的测量变得复杂。石英/粘土系统通常存在于各种环境中（河流，湖泊，海洋），并在与深海碳氢化合物钻探和CO2封存相关的技术工作中发挥重要作用。石油公司通常每口井花费数百万美元来资助勘探钻井作业，并且可能需要多个勘探任务才能找到一个好的地点。这项工作的结果可能会导致一个更好的计算模型，将允许石油公司在深海寻找点，以更高的精度钻探生产性石油威尔斯。 粘性沉积物的动力学受重力、静电力和水动力的相互作用控制。地球上的实验室不允许孤立地研究内聚力和粘附力，因为这些力通常被重力和重力沉降的影响所掩盖。因此，现有的粘性沉积物的动力学模型有严重的缺点，颗粒间力的大小和由此产生的絮凝率和可蚀性作为诸如颗粒大小、表面大小、颗粒材料和水的盐度等参数的函数的可靠的定标律是不可用的。这严重阻碍了粘性沉积物在其中发挥核心作用的一系列环境系统的预测建模工作，其中包括河流、湖泊、河口、沿海海洋、渔业和底栖生境。此外，鉴于深海钻探的高成本，计算沉积物迁移模型在深水油气勘探中也发挥着越来越重要的作用，改进建模工具将带来切实的经济效益。国际空间站的微重力实验室将使我们能够单独研究凝聚力和粘附力，而不受重力和相关沉降运动的干扰。通过这种方式，拟议的研究将使我们能够制定缩放律的动态粘性沉积物的粒度，颗粒材料和水的盐度的函数。国际空间站的实验将在很大程度上利用以前一次调查中使用的现有实验装置，以便将准备实验的时间和费用保持在最低限度。通过国际空间站实验确定的比例律随后将被应用到现有的颗粒解析计算流体动力学代码中，用于在有重力和无重力的条件下对粘性沉积物动力学进行详细的后续调查。拟议的研究将为河流、湖泊、河口、沿海海洋、渔业和海底栖息地等环境系统以及深海碳氢化合物勘探和拟议的二氧化碳封存策略提供先进的预测模型。在教育方面，拟议的研究项目将在微重力流体动力学和计算模型开发的广泛概念方面教育和培训一名博士后学者以及研究生、本科生和高中生。

PI: Luzzatto-Fegiz, PaoloProposal Number: 1638156The proposed research is focused on the study of forces between particles that tend to cluster. The physical system is that of sentiments of quartz and clay particles. The advantage of conducting experiments at the International Space Station (ISS) is that it will be possible to separate the forces acting on the particles among short range (adhesive forces) and long range (cohesive forces), since one can observe the clustering dynamics over very long time scales without gravitational settling, which complicates the measurements when doing experiments on Earth. The quartz/clay system is commonly found in a wide variety of environment settings (rivers, lakes, oceans) and plays an important role in technological efforts related to deep sea hydrocarbon drilling and CO2 sequestration. Oil companies typically spend millions per well to fund exploratory drilling operations, and might require multiple exploration missions to find one good site. Results from this work could lead to a better computation model that will allow oil companies to find spots on the deep sea for drilling productive oil wells with higher precision. The dynamics of cohesive sediment is governed by the interplay of gravitational, electrostatic and hydrodynamic forces. Earth-based laboratories do not allow for the investigation of cohesive and adhesive forces in isolation, as these are usually obscured by the effects of gravity and gravitational settling. Consequently, existing models for the dynamics of cohesive sediment have severe shortcomings, and reliable scaling laws for the magnitude of the inter-particle forces and the resulting flocculation rates and erodibility as functions of such parameters as grain size, surface size, grain material and water salinity are not available. This represents a serious impediment for predictive modeling efforts of a range of environmental systems in which cohesive sediment plays a central role, among them rivers, lakes, estuaries, the coastal ocean, fisheries and benthic habitats. Furthermore, given the high cost of deep-sea drilling, computational sediment transport models also play an increasingly important role in deep-water hydrocarbon exploration, where improved modeling tools will result in tangible economic benefits. The ISS microgravity laboratory will enable us to investigate cohesive and adhesive forces in isolation, without interference from gravity and the associated settling motion. In this way, the proposed research will allow us to formulate scaling laws for the dynamics of cohesive sediment as function of grain size, grain material and water salinity. The ISS experiments will to a large extent take advantage of an existing experimental apparatus that was employed in a previous investigation, so that the time and cost of preparing the experiments can be kept to a minimum. The scaling laws identified via the ISS experiments will subsequently be implemented into an existing, particle-resolving CFD code for detailed follow-up investigations of cohesive sediment dynamics under conditions with and without gravity. The proposed research will result in advanced predictive models for such environmental systems as rivers, lakes, estuaries, the coastal ocean, fisheries and benthic habitats, as well as for deep-sea hydrocarbon exploration and proposed CO2 sequestration strategies. On the educational side, the proposed research project will educate and train a postdoctoral scholar, as well as graduate, undergraduate and high school students in the broad concepts of microgravity fluid dynamics and computational model development.