Shallow dead zone dynamics: Experimental description and analysis of the three-dimensional flow structure of single dead zones and dead zone sequences, with special focus on their turbulent characteristics, coherent structures and water surface oscillatio

浅水流动并不简单，它们包含重要的形态不均匀性，导致复杂的流动结构。在流动横截面的相当大的横向变化的情况下，可以形成大的和缓慢的流体再循环体积：浅死区。这些区域对溶解物质的质量迁移和沉积物迁移有重大影响。此外，它们的水流结构已被证明是刺激水生物种生长的重要因素，因此它们是人工创造的，用于河流修复目的。目前，它们的流动结构和对质量运输的影响不能完全预测，由于缺乏知识，他们的流动动力学，和他们的依赖于当地的几何形状和传入的流特性。这项工作的目的是提高浅死区的三维流动动力学的理解，包括湍流，相干结构和水面振荡的时空特征。这些目标将通过一系列的示意性实验室实验来实现，实验重点是简单的死区（港口状）和死区序列（如河丁坝）的出现和淹没条件。实验将使用先进的立体粒子跟踪测速技术，以及同步压力和水位传感器进行。预计这项工作将创建一个第一个实验的三维描述的流结构在浅死区，并形成改进的流体动力学模型处理其流动动力学的基础。

Shallow flows are not simple, they contain important morphological inhomogeneities that lead to complex flow structures. In case of considerable lateral changes of the flow cross-section, large and slow recirculating volumes of fluid can be formed: the shallow dead zones. These zones have major effects on the mass transport of dissolved substances and on sediment transport. In addition, their flow structure has proven to be an important factor for stimulating the growth of the aquatic species, hence they are artificially created for river restoration purposes. Currently, their flow structure and the effects on mass transport cannot be totally predicted, due to the lack of knowledge of their flow dynamics, and their dependency on the local geometry and incoming flow characteristics. This work aims to improve the understanding of the three-dimensional flow dynamics of shallow dead zones, including the spatio-temporal characterization of turbulence, coherent structures and water surface oscillations. The goals will be achieved by a series of schematic laboratory experiments focusing on simple dead zones (harbor-like) and dead zone sequences (e.g. river groynes) for both the emerged and the submerged conditions. The experiments will be conducted using an advanced Stereo Particle Tracking Velocimetry technique, together with synchronous pressure and water level sensors. It is expected that this work will create one of the first experimental three-dimensional descriptions of the flow structure in shallow dead zones, and form the basis for improved hydrodynamics models dealing of their flow dynamics.