Investigating Turbulence-Driven Sediment Transport with Field Applications of Particle Image Velocimetry

通过粒子图像测速的现场应用研究湍流驱动的沉积物输送

• 批准号: NE/V008099/1
• 负责人: Andreas Baas
• 金额: $ 9.35万
• 依托单位: King's College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FV008099%2F1
• 关键词: Investigating; Turbulence; Driven; Sediment; Transport

Our current capabilities for predicting amounts of sand moved by wind over beaches and in deserts perform poorly when tested in the natural environment. Accurate predictions are crucial, however, to many practical problems in resource management and environmental engineering, such as beach deflation, coastal dune and habitat development, soil erosion, and dust emissions into the atmosphere. The principal limitation of the current models is that they calculate transport rate only as a function of a single time-averaged wind speed. We know, however, that wind-blown sand - even over uniform beaches and desert surfaces - displays intricate and shifting spatial patterns, most visibly in the form of streamers or so-called 'sand-snakes'. Previous research has suggested that these patterns are formed by individual gusts, or eddies, of wind that generate and drive the streamers over the surface.The research project will determine the precise functional relationships between eddies in natural winds and resultant sand transport over the surface, with the goal of establishing a new quantitative and predictive model that explicitly incorporates parameters related to the turbulence.We do this by applying state-of-the-art video imaging technology in field experiments on a beach. The International Partner is deploying a laboratory-grade measurement system for tracking eddies in the wind as well as airborne sand grains through a powerful laser beam, filmed by multiple high-speed video cameras from different viewing angles. The PI will add to this his technique of filming streamers with ordinary GoPro sports cameras and analysing the footage to measure the movements and grain densities of these patterns as they approach and enter the laser beam. The combination of these two types of Particle Image Velocimetry on different spatial scales allows us to interrogate the precise links between wind turbulence and sand movement so that we can establish a mathematical model.

我们目前的能力预测在海滩上风向的沙子和沙漠中的沙子量时，在自然环境中进行测试时的表现不佳。但是，准确的预测至关重要，对于资源管理和环境工程方面的许多实际问题，例如海滩通缩，沿海沙丘和栖息地的开发，土壤侵蚀以及尘埃排放到大气中。当前模型的主要限制是它们仅根据一次性平均风速计算运输速率。但是，我们知道，即使在统一的海滩和沙漠表面上，风吹沙的沙子也显示出复杂和转移的空间图案，最明显地以彩带或所谓的“砂刺”的形式出现。先前的研究表明，这些模式是由风产生和驱动流式磁带在表面上产生和推动流板的各个阵风或涡形形成的。研究项目将确定自然风中涡流之间的精确功能关系与表面上的沙子运输与产生的沙子运输与表面上的沙子运输，目的是通过与该技术相关的新定量模型来实现这一目标。海滩。国际合作伙伴正在部署一个实验室级测量系统，用于通过强大的激光束跟踪风中的涡流以及空气中的沙粒，该激光束由来自不同视角的多个高速摄像机拍摄。 PI将增加他的技术，该技术是通过普通的GoPro运动摄像头拍摄流媒体，并分析镜头，以测量这些图案接近并进入激光束的动作和谷物密度。这两种类型的粒子图像在不同的空间尺度上的结合使我们能够询问风湍流与沙子运动之间的精确联系，以便我们可以建立数学模型。