1 Oct 2025

Numerical Storm Surge Modeling and Probabilistic Analysis for Evaluating Proposed New Jersey Back Bays Inlet Closures

Abstract: The US Army Corps of Engineers, Philadelphia District, and the New Jersey Department of Environmental Protection are currently engaged in the New Jersey Back Bays (NJBB) Coastal Storm Risk Management Feasibility Study. The US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, conducted a numerical hydrodynamic modeling and probabilistic hazard analysis study to evaluate the effectiveness of storm surge barriers in reducing water levels in the NJBB. The numerical modeling study included the simulation of water levels and a comparison of water surface elevations and corresponding annual exceedance frequency between existing conditions and six final project alternatives. Results from the hydrodynamic simulations and probabilistic analysis are presented herein.

15 Sep 2025

Fiber-Reinforced-Polymer (FRP) Composite Sandwich Panel Barge Impact Modeling and Repair Testing: Dynamic and Static Finite Element Analysis (FEA) Predictions for Impact and Flexural Testing Validated with Experiments

Abstract: The US Army Engineer Research and Development Center has studied the functionality, durability, and structural integrity of fiber-reinforced-polymer (FRP) composite materials in civil works infrastructure. Compared to traditional materials like steel, composites offer a high strength-to-density ratio and excellent resistance to environmental degradation. The purpose of this study is to evaluate the dynamic response of FRP composite sandwich panels subjected to a barge impact with typical masses and velocities. A finite element model was created for FRP composite sandwich panels by incorporating cohesive interaction properties to evaluate the damage between three-dimensional (3D) layers. To validate the model, several FRP composite sandwich panels were experimentally subjected to low-velocity impacts and compared to the models. Moreover, flexural experiments were performed to determine the reduction of structural performance after impact and the efficacy of two different repair methods. Numerical predictions were developed to explore the damage caused by the interfaces of FRP composite layers. Load, deflection, and velocities were obtained experimentally and with finite element models.

19 Aug 2025

Numerical Modeling of Coastal Processes with Beneficial Use of Dredged Sediment in the Nearshore at Jekyll Island, Georgia

Abstract: This report provides numerical model results to assist the US Army Corps of Engineers–Savannah District (SAS). These results evaluate beneficial use alternatives for the sediment from an advance maintenance widener of the Brunswick Harbor Entrance Channel between stations −14+000 and −28+000. This study applied a coastal wave, hydrodynamic and sediment transport model (Coastal Modeling System), and a shoreline change model (GenCade), focusing on developing and simulating placement alternatives. Subaerial placement model results indicate better shore and beach preservation than at the nearshore nourishment. Placing sediment closer to the “transition zone” between the revetment and natural beach will increase the volume of sand that remains in that area. Some sediment is predicted to return to the channel, but these volumes are small fractions of the placed material. GenCade results indicate that the transition zone rock debris decreases shoreline erosion. Removing it has less impact on that area than any of the subaerial nourishments, but this prediction does not include profile equilibration that may occur after the first 4 months. Overall, model results indicate that subaerial placement will have strong positive response at the eroding beach, and related increases to channel infilling rates are relatively small.

13 May 2025

Development and Testing of the FRAME Tool on a 200-Mile Reach of the Lower Mississippi River

Abstract: Understanding the likely long-term evolution of the Lower Mississippi River (LMR) is a challenging mission for the US Army Corps of Engineers (USACE) that remains difficult for conventional river engineering models. A new type of model is currently in development, tasked with revealing uncertainty-bounded trends in sediment transport and channel morphology over annual, decadal, and centennial timescales. The Future River Analysis and Management Evaluation (FRAME) tool is being designed with river managers and planners in mind to provide exploratory insights into plausible river futures and their potential impacts. A unique attribute of the tool is its hybrid interfacing of traditional one-dimensional hydraulic and sediment transport modeling with geomorphic rules for characterizing the morphological response. This report documents the development of a FRAME test-bed model for a 200-mile reach of the Mississippi River upstream of Vicksburg, Mississippi. This testbed allowed development and testing of the prototype FRAME tool in a data-rich environment. This work identified proposed future developments to provide river managers and planners with a fully functional tool for delivering insights on long-term morphological response in river channels across a variety of spatial and temporal scales.

3 Oct 2024

Comite Diversion Numerical Model Study

Abstract: The Comite River diversion project is designed to reduce flooding along the Comite and Amite Rivers during flood events by diverting flow from the Comite River into the Mississippi River above Baton Rouge, Louisiana. The flow is diverted from the Comite River along a diversion canal to the Lilly Bayou Control structure. This structure allows the Comite River flow to enter the Mississippi River floodplain. A numerical model was created to evaluate the impacts associated with this addition of water to the Mississippi River. A 2D Adaptive Hydraulics numerical model was created to quantify the system impacts associated with the diverted flow in conjunction with possible system modifications to control the flow pathway. The impact of the diversion was determined to be heavily dependent on the flow and stage of the Mississippi River. At higher stages and flows, the flow diverted by the Lilly Bayou Control structure is negligible in relation to the much larger Mississippi River flow and therefore the impacts of the added flow are significantly less than at lower Mississippi River stages. At lower Mississippi River flows and stages, the added flow from the Lilly Bayou Control structure has a larger impact on the inundation due to the larger relative amount of diverted flow in relation to the Mississippi River. Ultimately, the diverted Comite River flow has some incremental increase in water levels at all Mississippi River stages.

18 Apr 2024

Neural Ordinary Differential Equations for Rotorcraft Aerodynamics

Abstract: High-fidelity computational simulations of aerodynamics and structural dynamics on rotorcraft are essential for helicopter design, testing, and evaluation. These simulations usually entail a high computational cost even with modern high-performance computing resources. Reduced order models can significantly reduce the computational cost of simulating rotor revolutions. However, reduced order models are less accurate than traditional numerical modeling approaches, making them unsuitable for research and design purposes. This study explores the use of a new modified Neural Ordinary Differential Equation (NODE) approach as a machine learning alternative to reduced order models in rotorcraft applications—specifically to predict the pitching moment on a rotor blade section from an initial condition, mach number, chord velocity and normal velocity. The results indicate that NODEs cannot outperform traditional reduced order models, but in some cases they can outperform simple multilayer perceptron networks. Additionally, the mathematical structure provided by NODEs seems to favor time-dependent predictions. We demonstrate how this mathematical structure can be easily modified to tackle more complex problems. The work presented in this report is intended to establish an initial evaluation of the usability of the modified NODE approach for time-dependent modeling of complex dynamics over seen and unseen domains.

8 Apr 2024

Coastal Modeling System User’s Manual

Abstract: The Coastal Modeling System (CMS) is a suite of coupled 2D numerical models for simulating nearshore waves, currents, water levels, sediment transport, morphology change, and salinity and temperature. Developed by the Coastal Inlets Research Program of the US Army Corps of Engineers, the CMS provides coastal engineers and scientists a PC-based, easy-to-use, accurate, and efficient tool for understanding of coastal processes and for designing and managing of coastal inlets research, navigation projects, and sediment exchange between inlets and adjacent beaches. The present technical report acts as a user guide for the CMS, which contains comprehensive information on model theory, model setup, and model features. The detailed descriptions include creation of a new project, configuration of model grid, various types of boundary conditions, representation of coastal structures, numerical methods, and coupled simulations of waves, hydrodynamics, and sediment transport. Pre- and postmodel data processing and CMS modeling procedures are also described through operation within a graphic user interface—the Surface Water Modeling System.

4 Apr 2024

Use of Sediment Tracers to Evaluate Sediment Plume at Beaufort Inlet and Adjacent Beaches, North Carolina

Abstract: This report documents a numerical modeling investigation on the transport of sediment material placed on designated disposal sites adjacent to Beaufort Inlet, North Carolina. Historical and newly collected wave and hydrodynamic data around the inlet are assembled and analyzed. The data sets are used to calibrate and validate a coastal wave, hydrodynamic and sediment transport model, the Coastal Modeling System. Model alternatives are developed corresponding to different material placement sites. Sediment transport and sediment plume distribution are evaluated within and around the immediate vicinity of the Beaufort Inlet estuarine system for a representative summer and winter month. Results of model simulations show that high flows occur along navigation channels and low flows occur outside the inlet in open ocean area. Sand materials placed in nearshore sites tend to be trapped in and move along navigation channels entering the inlet. In offshore placement sites the sediment plume shows slow spreading and no significant sand migration from its release locations. Simulations for the summer and winter month present similar distribution patterns of sediments originating from placement sites.

11 Jan 2024

Simulated Barge Impacts on Fiber-Reinforced Polymers (FRP) Composite Sandwich Panels: Dynamic Finite Element Analysis (FEA) to Develop Force Time Histories to Be Used on Experimental Testing

Abstract: The purpose of this study is to evaluate the dynamic response of fiber-reinforced polymer (FRP) composite sandwich panels subjected to typical barge impact masses and velocities to develop force time histories that can be used in controlled experimental testing. Dynamic analyses were performed on FRP composite sandwich panels using the finite element method software Abaqus/Explicit. The “traction-separation” law in the Abaqus software is used to define the cohesive surface interaction properties to evaluate the damage between FRP composite laminate layers as well as the core separation within the sandwich panels. Numerical models were developed to better under-stand the damage caused by barge impacts and the effects of impacts on the dynamic response of composite structures. Force, displacement, and velocity time histories were obtained with finite element modeling for several mass and velocity cases to develop experimental testing procedures for these types of structures.

15 Jun 2022

Foundational Principles in the Development of AdH-SW3, the Three-Dimensional Shallow Water Hydrodynamics and Transport Module within the Adaptive Hydraulics/Hydrology Model

Abstract: This report details the design and development of the three-dimensional shallow water hydrodynamics formulation within the Adaptive Hydraulics/Hydrology model (AdH-SW3) for simulation of flow and transport in rivers, estuaries, reservoirs, and other similar hydrologic environments. The report is intended to communicate principles of the model design for the interested and diligent user. The design relies upon several layers of consistency to produce a stable, accurate, and conservative model. The mesh design can handle rapid changes in bathymetry (e.g., steep-sided navigation channels in estuaries) and maintain accuracy in density-driven transport phenomena (e.g., thermal, or saline stratification and intrusion of salinity).