ADCIRC

ADCIRC (Advanced Circulation Model for Coastal Ocean Hydrodynamics) is a numerical model developed for the specific purpose of generating long time periods of hydrodynamic circulation along shelves, coasts, and within estuaries. The intent of the model is to produce long numerical simulations for very large computational domains in a unified and systematic manner.

» Overview

Widely Applicable

ADCIRC has been extensively applied over the past nine years by both the U.S. Army and Navy for tidal and hurricane storm surge predictions in regions including the western North Atlantic, Gulf of Mexico and Caribbean Sea, the Eastern Pacific Ocean, the North Sea, the Mediterranean Sea, the Persian Gulf, and the South China Sea. Other users of ADCIRC include governmental agencies, consulting firms, and university researchers for applications ranging from real time hurricane storm surge predictions to impact studies of sewage outfall placement.




Features

Computational models of flow and transport in continental margin waters are used to predict free surface elevation and currents for applications ranging from evaluating coastal inundation, defining navigable depths and currents in near shore regions, to assessing pollutant and/or sediment movement on the continental shelf. The ability of these computer models to accurately represent the actual waterbody physics depends on the flow processes and phenomena considered in the calculation, the validity of the governing equations, the body and boundary forcing functions, the scope of the computational domain, the accuracy and robustness of the numerical algorithms, and finally the temporal and spatial discretization applied in the calculation. It is critical to delineate these interrelated issues in advancing model capabilities.

It is certain that high spatial and temporal grid resolution is one of the key factors in improving the accuracy of flow calculations in the coastal ocean due to the broad wave number content of the flow. In addition highly resolved grids are necessary to assess algorithm convergence properties, estimate errors for a particular calculation and to subsequently evaluate the performance of the governing equations, processes, forcing functions, and domain. It is clear that the only way to gain significant improvements in grid resolution is to develop scalable parallel computational codes for coastal ocean hydrodynamics.

Flow vectors computed by ADCIRC due to Hurricane Andrew’s pressure heads.

Model Development

The investigators on this project have been involved in developing numerical models for coastal ocean flow over the past two decades in cooperation with investigators at the University of North Carolina at Chapel Hill (R.A. Luettich), the University of Texas at Austin (M.F. Wheeler and C. Dawson), the University of Oklahoma (R. Kolar), the State of Texas (Jurji), and the Waterways Experiment Station (N. Scheffner). Issues which have been investigated include algorithm development and analysis, code implementation, model validation/verification, as well as applications which in turn drive algorithm development. The current computational framework which incorporates the algorithms, codes, and knowledge base developed through this research has been designated as the ADCIRC (Advanced Circulation) Model, a finite element based code of the two and three dimensional shallow water equations.