An estuarine and coastal sand transport model

Interruption of sand transport is the most persistent worldwide coastal problem. Wave action produces sand transport which is not a problem in some areas but in others results in coastal erosion, obstruction of harbor entrances, and permanent loss of sand. Conflict between saving sand and bypassing it is caused by a lack of methods to manage this valuable resource. Separate elements of control have been used with varying degrees of success; now it is proposed to incorporate subsystems into an integrated system for management of the littoral transport. A coastal sand management system is to be evaluated using three principal subsystems: (1) a mobile jet pump for use with a crater sink and fluidization accessories; (2) interlocking inertial modules which simulate structural materials because of high intergrain stresses; and, (3) the tactical deployment of phase dependent roughness elements to direct (or reverse) the net transport of sand. A coherent sand management system promises to make a start toward true control of littoral sand transport. In addition, there is the prospect of eventually establishing the first self maintaining harbors. It is attractive to consider systems which would be operative within reasonable cost, which may be entirely submerged, and which are capable of operating without regard to surface seakeeping problems. Some aspects of the system indicate possible use of the mobile jet pump as a means for estimating longshore transport in the field, use in archaeology, and as a dredging and maintenance tool for small nations whose investment capital could not support massive dredging operations.

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Sand transport model of barchan dune equilibrium

Sedimentology ◽

10.1111/j.1365-3091.1978.tb00316.x ◽

1978 ◽

Vol 25 (3) ◽

pp. 307-338 ◽

Cited By ~ 120

Author(s):

A. D. HOWARD ◽

J. B. MORTON ◽

MOHAMED GAD-EL-HAK ◽

DEBORAH B. PIERCE

Keyword(s):

Transport Model ◽

Sand Transport ◽

Barchan Dune

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MODELING ALTERNATIVES FOR EROSION CONTROL AT MATAGORDA COUNTY,TEXAS, WITH GENCADE

Coastal Engineering Proceedings ◽

10.9753/icce.v33.sediment.97 ◽

2012 ◽

Vol 1 (33) ◽

pp. 97

Author(s):

Ashley Frey ◽

James Rosati, III ◽

Kenneth J. Connell ◽

Hans Hanson ◽

Magnus Larson

Keyword(s):

Engineering Design ◽

Transport Model ◽

Erosion Control ◽

Shoreline Change ◽

Sand Transport ◽

Texas Coast

Matagorda Peninsula and Sargent Beach, Texas, USA, have experienced some of the highest rates of erosion along the Texas coast. In order to increase protection from tropical events and slow beach habitat erosion, several structural alternatives were studied. These alternatives were modeled with GenCade, a newly developed 1D shoreline change and sand transport model. GenCade was calibrated and validated over the 60 miles of shoreline in Matagorda County. Then separate GenCade grids and simulations were conducted for the structural alternatives at Matagorda Peninsula and Sargent Beach. At Matagorda Peninsula, different groin lengths and spacing between groins were modeled with and without beach fills and mechanical bypassing. The alternatives at Sargent Beach included detached breakwaters, groins, and beach fills. Although the process described in this paper only includes a small part of a more detailed study, these simulations helped lead to a recommendation of the selected alternatives for preliminary engineering design.

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Using Video Monitoring to Test a Fetch-Based Aeolian Sand Transport Model

Journal of Marine Science and Engineering ◽

10.3390/jmse8020110 ◽

2020 ◽

Vol 8 (2) ◽

pp. 110 ◽

Cited By ~ 1

Author(s):

Pam Hage ◽

Gerben Ruessink ◽

Zilla van Aartrijk ◽

Jasper Donker

Keyword(s):

Wind Velocity ◽

Transport Model ◽

Transport Rate ◽

Beach Sand ◽

Sand Transport ◽

Winter Period ◽

Aeolian Sand ◽

Aeolian Transport ◽

Aeolian Sand Transport ◽

Strong Winds

Transport of beach sand to the foredune by wind is essential for dunes to grow. The aeolian sand transport rate is related to wind velocity, but wind-based models often overpredict this transport for narrow beaches (<100 m). To better predict aeolian sand transport, the fetch-based Aeolus model was developed. Here, we qualitatively test this model by comparing its transport-rate output to visual signs of aeolian transport on video imagery collected at Egmond aan Zee, the Netherlands, during a six-month winter period. The Aeolus model and the Argus images often agree on the timing of aeolian transport days, except when transport is small; that is not always visible on the Argus images. Consistent with the imagery (minimal signs of aeolian activity in strong winds), the Aeolus model sometimes predicts the actual transport to be smaller than the potential transport. This difference is largest when wind velocity is large, and its direction is cross-shore. Although transport limitations are not predicted to be common, the results suggest that their effect on the total transport in the study period was substantial. This indicates that the fetch distance should be taken into account when calculating aeolian transport for narrow beaches on longer timescales (>weeks).

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Wave influence on coastal sand transport paths in a tidally dominated environment

Ocean and Shoreline Management ◽

10.1016/0951-8312(88)90025-2 ◽

1988 ◽

Vol 11 (6) ◽

pp. 449-465 ◽

Cited By ~ 8

Author(s):

Charitha Pattiaratchi ◽

Michael Collins

Keyword(s):

Sand Transport ◽

Coastal Sand

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Impacts of Fracture Roughness and Near-wellbore Tortuous on Proppant Transport Within Hydraulic Fractures

10.21203/rs.3.rs-1118961/v1 ◽

2021 ◽

Author(s):

Di Wang ◽

Bingyang Bai ◽

Bin Wang ◽

Dongya Wei ◽

Tianbo Liang

Keyword(s):

Hydraulic Fracturing ◽

Analytical Model ◽

Volume Fraction ◽

Transport Model ◽

Sand Transport ◽

Hydraulic Fractures ◽

Fracture Roughness ◽

Transport Velocity ◽

Sand Bank ◽

The Impact

Abstract For unconventional reservoirs hydraulic fracturing design, a greater fracture length is a prime factor to optimize. However, core observation results from Hydraulic Fracturing Test Site (HFTS) show the propped fractures are far less or shorter than expected which suggests the roughness and tortuous of hydraulic fractures are crucial to sand transport. In this study a transport model of sands is first built based on experimental measurements on the height and transport velocity of sand bank in fractures with predetermined width and roughness. The fracture roughness is quantified by using surface height integral. Then, three-dimensional simulations are conducted with this modified model to further investigate the impact of fractures tortuous on sand transport, from which an analytical model is established to estimate the propped length of hydraulic fractures at a certain pumping condition. Experiments results show that height of sand bank in roughness fracture is 20-50% higher than that in smooth. The height of sand bank decreases with the reduction of slurry velocity and increases with the sand diameters increasing. Sand sizes do little effect on the transport velocity of sand bank but the increase in slurry velocity and sand volume fraction can dramatically enhance the migration velocity of sand bank. The appearance of tortuous decreases the horizontal velocity of suspended particles and results in a higher sand bank compared with that in straight fractures. When the sand bank gets equilibrium at the tortuous position, it is easy to produce vortices. So, there is a significant height of sand bank change at the tortuous position. Moreover, sand plugging can occur at the entrance of the fractures, making it difficult for the sand to transport deep in fractures. This study explains why the propped length of fractures in HFTS is short and provides an analytical model that can be easily embedded in the fracturing simulation to fast calculate dimensions of the propped fractures network to predict length and height of propped fractures during fracturing.

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