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<Environmental Fluid Modeling> Rho-Taek Jung Date Title 2 June MEC Ocean Model Introduction, Hydrostatic Model, Full-3D Model, Eddy Viscosity, Boundary Condition 9 June Exercise1: MEC Model Manual Description
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<Environmental Fluid Modeling> Rho-Taek Jung Date Title 2 June MEC Ocean Model Introduction, Hydrostatic Model, Full-3D Model, Eddy Viscosity, Boundary Condition 9 June Exercise1: MEC Model Manual Description Pre-Process and Execution of Computer Simulation of Oceanic Flow Home Work to All 7 July Exercise2: Presentation of Simulation Results
Numerical Ocean Circulation Model Global Scale Modular Ocean Model (MOM : GFDL) Earth Simulator Local Scale Princeton Ocean Model (POM) Marine Environmental Committee Model (MEC Model) Washington university
マリノフォーラム21パンフレットより MEC Ocean Model(Introduction) 1. Free Code developed by MEC (Marine Environmental Committee, of which in SNAJ) 2. Organized University University of Tokyo, Kyushu University, Osaka University, Osaka Prefecture University 3. Request : Oceanic flow simulation around marine artifacts 4. Hydrostatic Model + Full-3D Model for meso-scale for human or artifact scale 5. Use the merit of two models 6. Strong source and sink flow around artifacts are occurred (Density Current Generator)
z z= y x z=-H MEC Ocean Model(Equations) Hydrostatic approximation, Boussinesq approximation (1) (2) (3) (4) (1’)
MEC Ocean Model(Boundary Condition) Bottom (5) (6) Surface : flow particle keeps on it through all subsequent time (7) (8) Integrating (2) under (5) and (6) (9) Integrating (1) from the sea surface (10)
MEC Ocean Model(Tracer Equation) Temperature and Salinity (11) (12) Boundary Condition (13) at bottom (14) at surface
MEC Ocean Model(Eddy viscosity, Eddy diffusivity) Horizontal eddy viscosity and eddy diffusivity : The rule of Richardson’s 4/3 which relates on the grid spacing. D0 : reference grid space Vertical eddy viscosity and eddy diffusivity : It can be represented by stratification function.
MEC Ocean Model(Numerical Scheme) Mainly Euler-backward scheme, Upwind scheme, Central scheme Process of Primitive variables solution 1. Calculation of (3)(4)(2) 2. Calculation of (9) 3. Calculation of at surface (7) 4. Calculation of (10) 5. Output
MEC Ocean Model(Full-3D: Numerical Solution) Staggered arrangement Grid System Cartesian Coordinate system MAC method Explicit method Third order upwind scheme (Convection Term) Second central scheme (Diffusion Term) SOR(Poisson equation of pressure) Turbulence Model( model, SGS model, horizontal and vertical eddy viscosity coefficient)
MEC Ocean Model(Full-3D) (15) (16) Turbulence Model 1. Horizontal and vertical eddy diffusivity coefficient 2. SGS(SubgridScale) Model 3. model
MEC Ocean Model(Full-3D: Turbulence Model) 1. Horizontal and vertical eddy diffusivity coefficient 2. SGS(SubgridScale) Model smagolinsky constant width of filter = 3. model
MEC Ocean Model(Combine with Full-3D: Turbulence Model) Special treatment of eddy diffusivity around interface between hydrodynamic model and full-3d model HD Full-3D HD
MEC Ocean Model(Combine with Full-3D : Time Interaction) N+1(step) Large dT N(step) ① ①‘ HD TIME ② ② ④ Full-3D TIME ③-1 ③-・・・ ③-n Small dT Variables(Velocity,Temp.,Sali.,Tide) are interpolated
MEC Ocean Model(Full-3D: Numerical Solution) Overview of Full-3D subroutines Ipola flux interpolation from hydrostatic model region to full-3d region. Turb calculation of eddy diffusivity by chosen one of turbulence model Gridmv calculation of moving velocity at surface due to the change of tide Bcvel,bctemp,bcsal boundary condition for velocity, temperature, and salinity Temp calculation of transfer equation for temperature Sal calculation of transfer equation for salinity Convct calculation of convect term of momentum equation Buoy calculation of buoyancy term of momentum equation Vis calculation of viscous term of momentum equation Pres calculation of pressure and renew the value of the velocity Opt1 print out the calculation results
MEC test Simulation(DCG in Gokasho Bay) After 12 hours After 96hours