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Source: https://erdc-library.erdc.dren.mil/jspui/ A time-varying three-dimensional (3-D) numerical hydrodynamic, salinity, and temperature model called CH3D-WES has been developed. The water surface, 3-D velocity field, and 3-D salinity and temperature fields are computed. Major physical processes affecting circulation and vertical mixing of a large water body are modeled. A particular feature of the model is the solution of transformed equations on a boundary-fitted grid in both the horizontal and vertical planes. The horizontal grid is a general nonorthogonal curvilinear grid, whereas the vertical grid is normally referred to as a sigma-stretched grid. This user's guide presents a detailed discussion of the theoretical aspects of the 3-D model (e.g., basic equations, boundary conditions, turbulence closure, etc.). This discussion is followed by a discussion of the organization of the computer code and input data requirements.

Source: https://erdc-library.erdc.dren.mil/jspui/ As a part of the New York (NY) Bight Feasibility Study, a three-dimensional, time-varying numerical hydrodynamic and transport model of the NY Bight was developed by the U.S. Army Engineer Waterways Experiment Station. For this purpose, the three-dimensional hydrodynamic model CH3D-WES was used, along with a boundary-fitted grid in the horizontal and 5-10 sigma layers in the vertical. The model was calibrated and verified with the field data measured in April and May 1976. As a demonstration of the feasibility of long-term simulation, hydrodynamics and transport were modeled for the period April-October 1976. Model results were furnished as input to a water quality model of the NY Bight, which reproduced successfully the hypoxic event of 1976. This user's reference manual presents a brief description of the theory of the numerical model and its various features. The structure of the computer code, the function of various subroutines, the formats of input data, various data files required, and available output options are described in detail. For illustrative purposes, sample listings of input files are furnished for an example case simulating hydrodynamics and transport in the NY Bight for the month of April 1976.

Source: https://erdc-library.erdc.dren.mil/jspui/ A previously calibrated numerical three-dimensional hydrodynamic model for Los Angeles-Long Beach Harbors, California, was applied to study the combined effects of tide and wind on circulation. The model was calibrated and verified successfully with field data for a summer wind condition. In this report the calibration is compared to a no-wind condition to understand the effects of typical wind conditions on circulation. Also, wind conditions for approaching (winds from the southeast) and passing (winds from the north) frontal systems, typical of fall-winter weather patterns, were simulated. Results indicated the effects of wind can be significant. NOTE: This file is large. Allow your browser several minutes to download the file.

Source: https://erdc-library.erdc.dren.mil/jspui/ As a part of the New York (NY) Bight Feasibility Study, a three-dimensional hydrodynamic model of the NY Bight was developed and applied by the Coastal Engineering Research Center of the U.S. Army Engineer Waterways Experiment Station. The study used the three-dimensional hydrodynamic model CH3D-WES for this purpose. A 76 x 45 cell boundary-fitted curvilinear grid was employed in the horizontal and five to ten sigma layers were used in the vertical. Steady-state and diagnostic tests were initially performed, using M2 and mixed tides, cross-shelf gradients, winds, and freshwater flows in the Hudson River. All of the tests were successful in reproducing known circulation patterns of the NY Bight system. The model was next successfully calibrated and verified against prototype tidal elevations and currents measured during April and May 1976. As a demonstration of the feasibility of long-term modeling, the hydrodynamics, including salinity and temperature, were simulated for the period April-October 1976. Model results compared favorably with available prototype temperature measurements. Model output was furnished to a water quality model of the NY Bight, which successfully reproduced the hypoxic event of 1976. Model results also were used successfully to run particle tracking and oil spill models of the NY Bight. Finally, the model was demonstrated for the Long Island Sound and East River areas, for the period of May-July 1990. Computed results for elevation, velocity, salinity, and temperature in the Sound as well as net flux in the East River matched measurements reasonably. On the basis of the study results, recommendations are made for monitoring in the NY Bight to improve model predictions in the future. NOTE: This file is large. Allow your browser several minutes to download the file.

Source: https://erdc-library.erdc.dren.mil/jspui/ The purpose of the study described in this report was to determine the impact of Phase 1 of three different plans (Schemes A, C, and D) for the Ports of Los Angeles and Long Beach on three-dimensional (3-D) hydrodynamics and water quality. This objective was accomplished by applying a 3-D numerical hydrodynamic model called CH3D in conjunction with a modified version of a water quality model called WASP. In a previous study under the Harbor Model Enhancement Program, the two models were calibrated and verified for the harbors using field data collected in the summer of 1987, and their use was demonstrated for Phase 1 of Plan B. The present study follows the same methodology as the previous study. Study results showed that in an overall sense, no single plan was significantly better or worse than the others. The landfill of the plans did not alter the tidal range and phase significantly. The greatest change in velocity occurred at the entrances to the harbors. Net circulation in the Inner Harbor areas showed a strong tendency to reverse under all four plan conditions. The plans will result in less rapid flushing in the Inner Harbor-Back Channel-Middle Harbor of the Port of Long Beach and impact dissolved oxygen in the same areas. However, dissolved oxygen concentrations for plan simulations were above 6.0 g/m^3. NOTE: This file is large. Allow your browser several minutes to download the file.

Source: https://erdc-library.erdc.dren.mil/jspui/ Oregon Inlet is a large tidal inlet through the barrier island system of North Carolina. In 1970, Congress authorized the Manteo (Shallowbag) Bay project which had provisions to stabilize Oregon Inlet with two jetties, deepen the ocean bar channel to 20 ft, and bypass across the inlet sand intercepted by the jetties. This report describes the results of a numerical study to consider coastal and inlet processes in the region surrounding the inlet under existing and planned project conditions. To accomplish the objectives of the study, a system of numerical models called Coastal and Inlet Processes (CIP) Numerical Modeling System was developed. It included models for wave propagation, wave-induced currents and setup, sediment transport within and beyond the surf zone, and profile response (onshore-offshore transport). Results from a separate study on numerical simulation of tides and storm surge for Oregon Inlet were utilized in the present investigation. As a test for an extreme event, the Ash Wednesday storm of March 1962 was simulated with the profile response model. There was good agreement between the calculated erosion amounts of the shore-normal profiles for Bodie and Pea Islands (on either side of Oregon Inlet) and values measured in the field. As an alternative to the stabilization of the entrance channel by construction of two jetties, a nonstructural solution proposed by the Department of the Interior was evaluated using the profile response model. The solution involved disposal of the dredged material from the entrance channel in the nearshore region with the idea that the material would be dispersed shoreward by wave action at a rate sufficient to prevent dredging-induced beach erosion. The results of the model indicated that on the average only 25 percent of the disposed material migrated toward the shore in a year. This migration was insufficient to prevent dredging-induced beach erosion. In order to perform an ocean bar channel dredging analysis, the US Army Engineer District, Wilmington (SAW), needed to know the period of time that dredges of the CURRITUCK and ATCHAFALAYA/MERMENTAU classes could operate in the entrance channel under the influence of waves. To study this problem, the wave propagation model was run allowing for wave-current interactions. Using the model results, SAW determined the limiting wave heights for dredging operations to be deepwater significant heights of 3.0 and 4.0 ft, respectively, for the two classes of dredges. The CIP system was used to study the erosion and accretion in the entrance channel as well as the lateral movement of the channel in the presence of the south jetty alone, simulating a construction sequence in which the south jetty was built before the north jetty. To accomplish this the longshore sediment transport model simulated an average year's wave climate and tide, using the results of the wave, wave-induced current, and tide models. The results of the simulation showed that during the year a total of 1,055,990 cu yd of material was trapped in the entrance channel, whereas a total of 660,000 cu yd of material was eroded between the southern boundary of the channel and the south jetty. It was determined that the entrance channel could move on the average about 150 ft per year toward the south jetty.

Source: https://erdc-library.erdc.dren.mil/jspui/ St. Marys Inlet is the main ocean entrance to the Naval Submarine Base, Kings Bay, Georgia. In order to accommodate Trident submarines at the base, it became necessary to modify the exterior navigation channel. This report describes details of a numerical modeling effort performed to study the effects of channel modifications on coastal processes near the inlet, especially channel shoaling rates. A system of numerical models, which included models for tides, waves, wave-induced currents, and noncohesive sediment (sand) transport, was used in the study. The system, together with two computational grids, was called Model B. It was used to study existing (base) as well as planned conditions. Plan 1 is to widen the navigation channel by 100 ft, deepen the channel to -49 ft mlw (46-ft project depth plus 3-ft advance maintenance), and extend the channel on the ocean side with a 20-deg bend to the south. Model B considered the simultaneous sand-tightening of a 1,000-ft segment of the south jetty. The tidal model was verified using field data taken on 10 November 1982. The average year's wave climate for the study area was obtained from 20-year hindcast data. The dataset included normal storms (but not hurricanes and tropical storms). It was used in running the wave and wave induced current models. The sediment transport model determined noncohesive sediment (sand) transport in the study area under the action of tides, waves and wave-induced currents. It considered a mean tide and the average year's wave climate. It was verified by comparing computed erosion/deposition rates in the navigation channel with those obtained from field surveys taken during 1980-81. There was good agreement both with respect to trends and magnitudes. While all four models were run for base conditions, only the tidal model and the sediment transport model were run for Plan 1 conditions to meet the urgent need for model results. Based on the model results and available information, recommendations on advance maintenance dredging are made for various reaches of the navigation channel. United States. Naval Facilities Engineering Command.

Source: https://erdc-library.erdc.dren.mil/jspui/ Often, large-scale engineering structures such as jetties or breakwaters are constructed in the nearshore region to stabilize navigation channels or protect harbor entrances and beaches. During construction, these structures may alter waves and currents. Waves break on such structures and the resulting turbulence causes material to be tossed into suspension and be transported from the region by wave-induced and other currents. This results in erosion at the toe of the structure since natural influx of material may not exist to replace that removed from the region. In order to ensure structural stability, it is necessary to fill this area with nonerodible material. As a result, extra quantities of material may be required, and construction costs may be overrun. To minimize cost increases due to scour during construction, it is necessary to estimate the likelihood and amount of potential scour during construction. Since breaking waves and the currents induced by them play a vital role in transporting sediment away from coastal structures, thus resulting in scour, it is important to predict wave-induced currents, with and without structures. The purpose of this study is to develop a generalized numerical model that will predict currents induced by breaking waves at locations with or without coastal structures. The model should be applicable to real-life bathymetries that are often arbitrary and irregular and must be computationally efficient and economical in view of the large numerical grids often required in engineering projects. The numerical model called CURRENT developed in this study employs the radiation stress approach of Longuet-Higgins and solves the vertically integrated equations of momentum and continuity using an alternating direction implicit scheme. It includes mixing and advection terms. The model has been applied to a case of normally incident waves on a plane beach. Results for setup matched the experimental data of Bowen, Inman, and Simmons. For obliquely incident waves on a plane beach, model results for longshore currents were compared with the analytical solution of Longuet-Higgins, first neglecting the effect of setup and later including the effect of setup. Agreement was excellent. As the numerical grid was made finer, the numerical results tended to converge toward the analytical solution. The numerical model was applied to a field situation corresponding to Oregon Inlet, North Carolina. The bathymetry was very irregular and complex owing to the presence of channels, shoals, etc. A variable grid was used, and the significant wave during a part of the Ash Wednesday storm of March 1962 was simulated. The numerical results obtained for this case appeared to be reasonable, and the computer costs were modest. For user convenience, model input, output, and files are described and two sample applications are presented.