Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 15 of 15 for “"sediment entrainment"”.
-
Mechanisms of Sediment Entrainment and Transport in Rotorcraft Brownout
… induced by a small-scale rotor hovering above a sediment bed was studied using high-speed flow visualization and particle image velocimetry (PIV). The high frame rate of the camera, combined with advanced particle recognition and tracking software, permitted an understanding of the temporal …
-
Particle motion in the near bed region of a turbulent open channel flow: Implications for bedload transport by saltation and sediment entrainment into suspension
… physical processes involved in the transport of sediment particles in the near bed region of a turbulent open channel flow. Two different aspects of this phenomenon are examined, namely the mode of transport denoted as saltation, and the process of particle entrainment into suspension. The main …
-
The Role of Turbulence on the Initiation of Sediment Motion
… role of turbulence on the incipient motion of sediment. For this purpose, well-controlled experiments are performed at the laboratory in a tilting flume. In these tests glass beads of the same size and density are used as the testing material to isolate the role of turbulence. State of the art …
-
The impact of dams, droughts, and tributary drainages on channel form and process : Rio Grande and Rio Chama, NM
… that channel systems evolve to convey the sediment loads and water discharges imposed upon them. Changes in sediment and water inputs may result in adjustments to channel geometry, bed texture, and related parameters. Over the last century, geomorphic processes along the Middle Rio Grande …
-
Development of the BASS rake acoustic current sensor : measuring velocity in the continental shelf wave bottom boundary layer
… shear stress can be sufficient to initiate sediment motion. The wave bottom boundary layer plays an important role in the processes of sediment entrainment and transport on the continental margins. This thesis documents the development, testing, and field use of a new instrument, the BASS …
-
On subannual variability in the abyssal ocean
… abyssal thermal fronts. A simplified model of sediment transport suggests that such variations in BML structure could significantly influence the dispersal of sediments resuspended by seabed mining activities. Second, idealized model experiments are conducted to explore the genesis of benthic …
-
On Subannual Variability in the Abyssal Ocean
… abyssal thermal fronts. A simplified model of sediment transport suggests that such variations in BML structure could significantly influence the dispersal of sediments resuspended by seabed mining activities. Second, idealized model experiments are conducted to explore the genesis of benthic …
-
Bedload Transport in Gravel-Bed Streams under a wide range of Shields Stresses
… a gravel bed may have either unimodal or bimodal sediment. This study examines more closely some aspects of bedload transport in gravel-bed streams and proposes explanations based on fluvial mechanics. First, a comparison between perennial and ephemeral gravel-bed streams is conducted. This …
-
Downstream suspended sediment dynamics of reservoir sediment flushing
Reservoir sediment flushing is increasingly considered beneficial to reduce sedimentation of reservoirs and maintain sediment supply downstream of impounded rivers. Nevertheless, flushing of the accumulated sediments downstream of the dam also bears numerous negative impacts. In this study, first …
-
The fluvial dynamics of compound meander bends
… Results suggest that patterns of flow, sediment entrainment, and planform evolution in compound meander bends are more complex than in simple meander bends. Moreover, interactions among local influences on the flow, such as outer bank blocks, local topographic steering, and locally high …
-
Wave-induced sediment transport on an estuarine intertidal flat
… tides are the primary processes responsible for sediment entrainment on estuarine intertidal flats, however a detailed understanding of the temporal and spatial variability of wave processes, and the way in which these control estuarine sediment transport, is lacking. The aim of this thesis is to …
-
Nearshore sediment dynamics in a mixed sand/mud environment
… receives significant quantities of fine, fluvial sediment from two river systems. Examining seabed geomechanical characteristics, sediment fluxes and morphological features in northern Poverty Bay provided the opportunity to study interactive processes, including sediment entrainment rates over …
-
Influence of riparian vegetation on near-bank flow structure and rates of erosion on a large meandering river
… flow structure, channel planform geometry, and sediment transport. These internal processes can be strongly influenced by the geotechnical properties of the channel banks and floodplains, as well as riparian and in-channel vegetation, modifying rates of erosion and mechanism of bank retreat, …
-
The Exchange of Fine Muddy Sediment in Gravel-Bed Fluvial Systems
The presence of fine muddy sediment (grain size < 0.1 mm) in streams has many impacts on the fluvial system and those relying on it, both humans and aquatic biota. Previously, fine sediment was considered a washload and has been ignored in transport models. More recently, it has been treated as …