Delft3D-FLOW

Toolbox

To perform a number of operations according to the Toolbox selected from the Toolbox tab in the Top Menu.  For all the supported models the startup toolbox is the quick mode of the model maker. In case of Delft3D-FLOW also the possibilities to (1) combine several sources of bathymetry and (2) to define a variable roughness are implemented.

Description

To add a description to the communication file (i.e. MDF file) about the purpose of the present model.

Domain

The data Group Domain contains the following sub-data groups in the Working Space: Grid, Bathymetry, Dry Points, Thin Dams, 2D Weirs, Structures.

• Grid is used to “Open a grid” file (.grd) and “Open a Grid enclosure “ file (.enc). The “number of layers” on the vertical is also defined, as well as their vertical spacing in percentage with respect to the total depth. Both, “Sigma layers” and “Zeta layers” are supported. In case of Sigma layers it is moreover possible to specify the thickness (in m) of the top and bottom layer (“Z top” and “Z bottom”). The “Latitude” of the grid used to compute the Coriolis force. “Orientation” defines the grid orientation as the angle between the true North and the y-axis of the Cartesian co-ordinate system.
• Bathymetry loads an existing depth file or can be used to define a bathymetry with a uniform water depth.
• Dry Points is used to define points that will be permanently dry during a computation, regardless of the local water depth. Add dry points (*.dry) to the model using the mouse or load it from an external file.
• Thin Dams are used to represent small obstacles (e.g. breakwaters, dams) in the model prohibiting flow between cells adjacent to them. Add thin dams (*.thd) to the model using the mouse or load it from an external file.
• 2D Weirs are used to represent hydraulic structures (e.g.spillways) in the model resulting in energy loss.
  
• Structures are not implemented yet

Time Frame

Defines the relation between the time axis of the real world (absolute time) and that of the simulation (relative time). “Reference Date” defines the arbitrary time t = 0 for all the time series computed by the simulation. “Start Time” and “Stop Time” defines start time and end time of the simulation. “Time Step” defines the Time step (in minutes) used in the computation. “Time Zone” defines the time difference between local time and GMT time and is used to determine the phases in the local time of the tidal components in case tide generating forces are included in the simulation.

Processes

The data Group Processes contains the following sub-data groups in the Working Space: Constituents, Physical, Anthropogenic. 

• Constituents: to include “Salinity”, “Temperature”, dispersion of “Pollutants and tracers” and transport of cohesive and/or non-cohesive “Sediment” in the simulation. For “Pollutants and tracers” and “Sediment” processes the names of the constituents need to be added. 
• Physical: to include the effect of Wind, Waves, Tidal forces and Secondary Flows.
• Anthropogenic (Dredging and Dumping). Not yet implemented.

Initial Conditions

To specify the initial values the computation will start with. Initial conditions are required for all processes specified under the Tab Processes. A number of options can be selected: “Uniform Values” to impose a constant value, “Initial Condition File”, “Restart File”, and “Map File” to impose a value from the external file.

Boundaries

To define the open boundaries, their location, type and other parameters describing them. Boundary conditions are stored in the “.bnd” file. The following “Type” of boundary conditions are available: “Water level”, “velocity”, “Neumann” (water level gradient), “discharge” or flux (total or per grid cell), “Riemann” (or weakly reflective boundary). Each boundary is identified by its “Name”, start and end coordinates (“M1”, “N1”; “M2”, “N2”), reflection coefficient (“Alpha”) and type of forcing (“Astronomic”, “Harmonic”, “Time-series”, “Q-H relation”). Moreover, the vertical profile for hydrodynamics can be prescribed as: “Uniform”, “Logarithmic”, “Per Layer”. The latter option applies neither to “Water Level” or “Neumann" boundary sections nor depth-averaged simulations.

Physical Parameters

To select or specify a number of parameters related to the physical conditions of the model area. The data Group Physical parameters contains the following sub-data groups in the Working Space: Constants, Roughness, Viscosity, Sediments, Morphology, Heat Flow, Wind. The  tabs for Constants, Roughness and Viscosity are always visible. The other tabs are only visible if the associated processes are switched on. 

• Constants: to define values for: “Gravity”, “Water Density”, “Air Density”. 
• Roughness: to specify the bottom roughness and the roughness of the side walls.
• Viscosity: to specify values for background horizontal and vertical eddy viscosity and diffusivity. Viscosity and diffusivity calculated with the Horizontal Large Eddy Simulation (“HLES”) can be added to it. For a 3D simulation, the vertical turbulent eddy viscosity and diffusivity which are added to the background value, are computed by one of the following models: “Constant”, “Algebraic”, “k-L”, “k-epsilon”
• Sediments: to specify sediment characteristics, in case you have “Sediment” switched on among the Processes. Sediment characteristics can be read from or saved to the “*.sed” file.
• Morphology: to specify parameters for bed-update and to carry out a full morphodynamic simulation.
• Heat Flux: not yet implemented in Delft Dashboard.
• Wind: to add a wind field in case you have “Wind” switched on among the Processes. A wind field can be saved to a “*.wnd” file.
• Tidal forces: with this option, the direct local influence of the tide-generating forces inside the modelling domain is taken into account.

Numerical Parameters

To specify parameters related to drying and flooding and some other advanced options for numerical approximations.

Discharges

To add localized discharges (e.g. rivers, intake stations, waste water outfalls). Location and discharge rates are respectively saved to a “.src” and “.dis” file.

Monitoring

To monitor the simulation during certain times on a higher temporal resolution than the rest of the grid points, by specifying the number of Stations, Cross sections or Drogues. Drogues can be released anywhere in the grid and the patch of the particle movement with the flow can be followed.

Output

To specify “Start Time”, “Stop Time”, “Time Step” at which output data will be stored in the Map output File. In case of simulation run with coupling, “Start Time”, “Stop Time” and “Time Step” at which data will be saved in the communication file can be specified. Moreover, the “History Time Step”, defining the time step at which information is stored for the observation points, can be specified. “Online visualization” is used to inspect results during the computation. “Online coupling” is available when you store results to the communication file.