High-fidelity and fast-running wave modeling near shore and at surf zone
Abstract
Amphibious vehicles are designed to operate in terrestrial-to-aquatic transition zones including the surf zone. Amphibious vehicles must be able to navigate fast and safely ashore through contested coastal environments. The complexity of coastal environment and the lack of understanding of the flow physics in these areas pose great challenges to autonomous vehicle control. This project aims at developing physics-based high-fidelity and fast-running wave models for coastal areas to provide environmental inputs to high-fidelity computational fluid dynamics (CFD) and medium-fidelity large amplitude motions program (LAMP) prediction of amphibious vehicle motions for developing fast-running algorithms for vehicle dynamics. Below are the overall three-year research tasks. ? We will simulate the wave field with realistic surf zone topography to account for the complex water motions between the sea surface and shallow bottom. The wave field will be simulated using phase-resolved model, with configurations including various ocean wave spectra, peak wave properties, and directionality functions. Wave-current interaction will be explicitly resolved. ? We will parametrize the effect of wave breaking and sea spray. The breaking of swells over sloping beaches will be simulated. Measurement data on the generation function of sea spray droplets will be incorporated into the simulation. The effect of the amphibious vehicles on the wave breaking and the transport of sea spray droplets will be studied. ? We will develop a physical-based, fast-running wave prediction tool with data assimilation. The strong shear current will be accounted for in the data assimilation process. We will further develop an adjoint model to warrant a fast and accurate reconstruction of wave field, even if the measurement data are only available at limited locations with partial information. ? We will collaborate closely with other team in this program. The wave field from our models will be provided to other teams as realistic environmental input for simulations of vehicle dynamics, such as CFD and LAMP. We will work with these teams to develop interfaces and tools necessary for the incorporation of our data. We will also provide guidance on waves to the experimentation and data collection team for the validation tasks. The proposed study builds on a suite of advanced simulation tools called WOW (Wave-Ocean- Wind) developed in house at University of Minnesota. Some of the modules of WOW, including WOW-wave, WOW-terrain, WOW-wavebreaking, and WOW-spray, can be readily applied to this project. We will focus on the use and improvement of two shallow-water, irregular-bottom wave models. Wave breaking and sea spray will be simulated to parametrize the impact of wave load on the vehicles and the effect of the sea spray on sensor performance. We will also develop a data assimilation capability that can utilize incomplete measurement data to reconstruct and predict the whole wave field details in real time. Our research will provide a fast-running wave-prediction tool, with the incorporation of the effects of complex surf zone topography, currents, wave breaking, sea spray, and the presence of vehicles. The wave simulation will also assist experiment studies for the validation of modeling and simulation. The wave simulation data will be provided to collaborators in this project. The data from the simulations will be valuable for the training and validation of fast-running algorithms of vehicle dynamics and control.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 26, 2018
- Source ID
- N000141812196
Entities
People
- Lian Shen
Organizations
- Office of Naval Research
- Regents of the University of Minnesota
- United States Navy