Sedimentation from forced wall jets versus free gravity flows: integrating tank experiments and field data into a physics-based depositional model

强制壁射流与自由重力流的沉积：将储罐实验和现场数据集成到基于物理的沉积模型中

• 批准号: 407609989
• 负责人: Dr. Jörg Lang
• 金额: --
• 依托单位: Abteilung 3 - Unterirdischer Speicher- und Wirtschaftsraum
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/407609989?language=en
• 关键词: Sedimentation; forced; wall; jets; versus

Recently, the impact of Froude supercritical density flows on deepwater clastic depositional systems has been increasingly recognized. These deposits are mainly preserved in the regions of expanding flows, where the aggradation is highest. Such regions of expanding flow can be modeled as supercritical jet flows. Submerged plane-wall jet flows, which emerge from an orifice into a standing water body and decelerate, can be considered as basic model for depositional processes related to expanding, point-sourced flows, like submarine fans and subaqueous ice-contact fans. The morphodynamics of expanding supercritical flows have a large impact on the dispersal of sediment and the resulting depositional architecture of subaqueous ice-contact fans, deposited by jet flows, and submarine fans, deposited by gravity flows, respectively. Jet flows and their deposits display a distinctive proximal to distal zonation. The densimetric Froude number exerts a primary control on the flow dynamics and the evolution from inertia-driven jets into density-driven gravity flows. The transition between plane-wall jets and gravity flows has a large impact on the deposition by expanding flows. The existing knowledge of jet flows and gravity flows, their hydrodynamic and morphodynamic evolution, and their deposits is insufficient to explain the characteristic bedform and facies successions. This project is designed to investigate these two flow types and develop recognition criteria for their deposits by integrating observations from tank experiments and field data. In the experimental part of the project, the morphodynamics of jet flows and gravity flows will be characterized in tank experiments, enabling the systematic variation of the controlling flow and sediment parameters. In the field part of the project, deposits related to zones of flow expansion from coarse-grained supercritical submarine fans will be studied. These field examples must enable a detailed characterization of the depositional architecture and facies successions and provide sufficient detail to invert for flow forcing. By the integration of the observations from the experiments and the outcrops a generic, physics-based model for deposition by expanding supercritical density flows will be developed.

最近，越来越多地认识到Froude超临界密度流对深水碎屑沉积系统的影响。这些沉积物主要保存在膨胀的膨胀区域中，其中促进量最高。这种扩展流动的区域可以建模为超临界射流流。淹没的平面壁喷气流从孔口出现到积水体中并减速，可以被视为与扩展，点击式流动相关的沉积过程的基本模型，例如海底风扇和水下冰接触风扇。扩展超临界流量的形态动力学对沉积物的扩散以及由喷气流量沉积和海底风扇产生的沉积物的扩散以及由重力流沉积的海底风扇的沉积结构产生了很大影响。喷气流及其沉积物显示出与远端分区的独特近端。密度弗洛德数量对流动动力学和从惯性驱动的喷气机的演变产生了主要控制，从而使密度驱动的重力流动。平面壁喷气机和重力流之间的过渡通过扩大流量对沉积产生了很大的影响。对喷气流量和重力流的现有知识，它们的流体动力和形态动力学的进化以及它们的沉积不足以解释特征性的床形和相位的术语。该项目旨在通过整合坦克实验和现场数据的观察结果来研究这两种流动类型，并制定其沉积物的识别标准。在项目的实验部分中，将在储罐实验中表征射流流和重力流的形态动力学，从而实现控制流量和沉积物参数的系统变化。在项目的现场部分，将研究与与粗粒超临界潜艇风扇的流动扩展区域有关的沉积物。这些现场示例必须能够对沉积架构和相位的详细表征进行详细的表征，并提供足够的细节以颠倒流动强迫。通过从实验和露头中的观察结果整合，将开发出基于物理的通用，基于物理的沉积模型，以扩大超临界密度流。