| 翻訳と辞書 |
MIKE 3
MIKE 3 is a computer program that simulates flows, cohesive sediments, water quality,and ecology in rivers, lakes, estuaries, bays, coastal areas and seas in three dimensions. MIKE 3 was developed by DHI Water.Environment.Health. MIKE 3 provides the simulation tools if you need to model 3D free surface flows and associated sediment or water quality processes. MIKE 3 is widely recognized as the gold standard for environmental and ecological studies. MIKE 3 can be used for assessment of hydrographic conditions for design, construction and operation of structures and plants in stratified waters, environmental impact assessment studies, coastal and oceanographic circulation studies, including fine sediment dynamics, sea ice simulations, lak hydrodynamics, water pollution studies and restoration projects, analysis of cooling water recirculation and desalination, water quality and ecological forecasting, phenomena whenever 3D flow structures is important.
==Introduction==
MIKE 3 is a generalised mathematical modelling system designed for a wide range of applications in areas such as oceanography,coastal regions and estuaries and lakes. The system is fully three-dimensional solving the momentum equation and continuity equationsin the three Cartesian directions.MIKE 3 simulates unsteady flow taking into account density variations, bathymetry and external forcing such as meteorology, tidal elevations, currents and other hydrographic conditions. MIKE 3 can be applied to oceanographic studies,coastal circulation studies, water pollution studies,environmental impact assessment studies,heat and salt recirculation studies and sedimentation studies. MIKE 3 is composed of three fundamental modules: The hydrodynamic (HD) module, the turbulence module and the advection-dispersion (AD) module. Various features such as free surface description, laminar flow description and density variations are optionally invoked within the three fundamental modules. A number of application modules have been implemented and can be invoked optionally. These are advection-dispersion of conservative or linearly decaying substances, a water quality (WQ)module describing BOD-DO relations, nutrients and hygienic problems, a eutrophication (EU) module simulating algae growth and primary production, and a mud transport (MT) module simulating transport along with erosion and deposition of cohesive material. A Lagrangian based particle (PA) module can also be invoked for simulating e.g. tracers, sediment transport or the spreading and decay of E-Coli bacteria. The modelling system is based on the conservation of mass and momentum in three dimensions of a Newtonian fluid. The flow is decomposed into mean quantities and turbulent fluctuations. The closure problem is solved through the Boussinesq eddy viscosity concept relating the Reynold stresses to the mean velocity field. To handle density variations, the equations for conservation of salinity and temperature are included. An equation of state constitutes the relation between the density and the variations in salinity and temperature and ñ if the MT calculations are invoked ñ mud concentration. In the hydrodynamic module, the prognostic variables are the velocity components in the three directions and the fluid pressure. The model equations are discretised in an implicit, finite difference scheme on a staggered grid and solved non-iteratively by use of the alternating directions' implicit technique. A phase and amplification analysis neglecting effects of viscosity, convective terms, rotation, density variations, etc. has been performed. Under these circumstances, the finite difference scheme is unconditionally stable.
The transport of scalar quantities, such as salinity and temperature, is solved in the advectiondispersion module using an explicit, finite difference technique based on quadratic upstream interpolation in three dimensions. The finite difference scheme, which is accurate to fourth order, has attractive properties concerning numerical dispersion, stability and mass conservation. The decomposition of the prognostic variables into a mean quantity and a turbulent fluctuation leads to additional stress terms in the governing equations to account for the non-resolved processes both in time and space. By the adoption of the eddy viscosity concept these effects are expressed through the eddy viscosity, which is optionally determined by one of the following five closure models:a constant eddy viscosity; the Smagorinsky sub-grid (zero-equation) model; the k- (one-equation) model; the standard k-ε (two-equation) model; and a combination of the Smagorinsky model for the horizontal direction and a k-ε model for the vertical direction.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「MIKE 3」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|