Sediment dynamics - Fluid and sediment bed interactions. What roles do fluid infiltration and grain shape play? - 3D numerical flume tank experiments

沉积物动力学 - 流体和沉积物床相互作用。

• 批准号: 258669118
• 负责人: Dr. Gerhard Bartzke
• 金额: --
• 依托单位: Zentrum für Marine Umweltwissenschaften (MARUM)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/258669118?language=en
• 关键词: Sediment; dynamics; Fluid; sediment; bed

This proposal was inspired by the inherent limitations in the quantification of the physical parameters (e.g., flow speed and grain shape) controlling sediment-fluid interactions in the direct vicinity of the sediment water interface and in the interior of a sediment bed. For investigation of the processes influencing the erosion characteristics of sediments beds, researchers commonly tested the transport behavior sediment beds empirically using laboratory flume tanks or in situ field investigations. However, a precise quantification of the processes occurring in the direct vicinity and in the interior of the sediment body, such as the fluid infiltration rates into the sediment bed, is difficult when using these techniques. Therefore, the physical processes in the interior of a sediment bed require further investigation. With a focus on the physical processes, occurring in the direct vicinity and in the interior of a sediment bed, the overall goal of this proposed research is to identify and quantify the role of fluid infiltration and grain shape variations on the transport behavior of sediments beds using 3D numerical simulations. It is hypothesized that: (1) the grain shapes found in natural sediment beds effect the amount of flow available to infiltrate into a sediment bed. (2) the textural bed composition (round versus non-round shapes) controls the inflow rates into a sediment bed and, hence, the erosion characteristics, and (3) natural grain shapes in sediment beds influence the erosion characteristics of sediment beds. By the use of the numerical Smooth Particle Hydrodynamics (SPH) method, uniform sediment beds composed of different grain shapes, will be tested in a 3D numerical flume tank under different current velocities. Physical features, such as the role of fluid inflow and grain shape variations on the transport characteristics will be measured at high resolution in the direct vicinity and in the interior of the sediment beds.

该提议的灵感来自于物理参数量化中的固有限制（例如，流速和颗粒形状）控制沉积物-流体在沉积物-水界面附近和沉积物床内部的相互作用。为了研究影响沉积物床层侵蚀特性的过程，研究人员通常使用实验室水槽或现场实地调查来经验性地测试沉积物床层的输运特性。然而，在使用这些技术时，很难精确地量化沉积体附近和内部发生的过程，例如流体渗入沉积床的速度。因此，沉积床内部的物理过程需要进一步研究。重点的物理过程，发生在附近和内部的沉积物床，本研究的总体目标是确定和量化的作用，流体渗透和颗粒形状的变化对运输行为的沉积物床使用三维数值模拟。假设：（1）天然沉积物床中发现的颗粒形状影响可渗透到沉积物床中的流量。(2)结构性床组成（圆形与非圆形形状）控制进入沉积物床的流入速率，并且因此控制侵蚀特性，以及（3）沉积物床中的天然颗粒形状影响沉积物床的侵蚀特性。利用光滑粒子水动力学（SPH）数值方法，在三维数值水槽中对不同流速下由不同颗粒形状组成的均匀沙床进行了试验。将在沉积物床的直接附近和内部以高分辨率测量物理特征，例如流体流入和颗粒形状变化对迁移特性的作用。