The National Shipbuilding Research Program. A Shipyard Program for NPDES Compliance. Appendix F - Bay/Estuary Model (B.E.S.T) Documentation
Abstract
This report presents a 2-D depth-averaged numerical model simulating water flow and reactive contaminant and sediment transport in bay/estuary systems. This model includes two computational modules: flow and transport. We use a splitting strategy to solve hydrodynamic equations where the method of characteristics (MOC) is employed first to compute circulation without taking into account eddy fluxes, and then the Galerkin finite element method is applied to deal with eddy fluxes. The computed flow results are used to compute the migration of sediments and contaminants in the transport module. Sediments can be either suspended in the water column or deposited on bed rock, and whose distributions are determined subject to advection, dispersion, and deposition/erosion processes. Contaminants, either organic or inorganic, may exist in the dissolved phase in the water column or in the interstitial water of the bed sediments. They may appear also as particulate chemicals on sediments through adsorption reactions. All chemical reactions, including aqueous complexation, adsorption/desorption, and volatilization, are assumed elementary and kinetic with reaction rates calculated based on the collision theory where forward and backward rate constants are determined experimentally. We employ a predictor-corrector strategy in the transport module where transport equations are computed in the predictor step with reaction rates estimated at the previous time, and rate correction is achieved node in the corrector step to obtain the concentration distributions at the present time. The Lagrangian-Eulerian approach is applied to solve the transport equations in the predictor step with a particle tracking technique used to handle advection. The Picard method and the Newton-Raphson method are used to solve the rate correction equations for sediment distribution and reactive chemistry, respectively, in the corrector step. Four examples are used to demonstrate the capability of this model.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 15, 2000
- Accession Number
- ADA448655
Entities
People
- Gour-tsyh Yeh
- Hwai-ping Cheng
- Jing-ru Cheng
Organizations
- National Steel and Shipbuilding Company