Automated Mesh/Grid Generation
SMS can be used to construct 2D and 3D finite element meshes and finite
difference grids of rivers, estuaries, bays, or wetland areas. The tools include
a sophisticated set of creation and editing tools to handle complex modeling
situations with relative ease. Several methods of finite element mesh creation
are available, allowing you to create any combination of rectangular and
triangular elements needed to represent your model domain. Both cartesian and
boundary-fitted grid creation tools are available to allow representation of a
model domain for finite difference models. The powerful mesh/grid creation
tools, coupled with GIS objects, are what makes SMS such an easy-to-use and
accurate modeling system!
There are two main methods for building models in SMS, the direct approach and
the conceptual modeling approach. With the direct approach, the first step is to
create a mesh or grid. The model parameters, source/sink data, and boundary
conditions are assigned directly to the nodestrings, nodes, and elements of the
mesh. This approach is only suited for very simple models.
The most efficient approach for building realistic, complex models is the
conceptual model approach. With this approach, a conceptual model is created
using GIS objects, including points, arcs, and polygons. The conceptual model is
constructed independently of a mesh or grid. It is a high-level description of
the site including geometric features such as channels and banks, the boundary
of the domain to be modeled, flow rates and water surface elevations of boundary
conditions, and material zones with material properties such as Manning's n
value. Once the conceptual model is complete, a mesh or grid network is
automatically constructed to fit the conceptual model, and the model data are
converted from the conceptual model to the elements and nodes of the mesh
network.
GIS Tools
SMS will allow you to take advantage of all types of GIS data available for
hydraulic modeling. The Map module of SMS includes a complete set of tools for
importing, creating, and manipulating GIS vector and raster data. ArcGIS/ArcView
is not a required component of the SMS software! You will find that SMS can work
with your GIS data effectively with or without ArcGIS. A few of the powerful
tools in SMS include:
- Robust algorithms have been developed to allow you to handle large data sets
(such as bathymetry data collected by LIDAR survey) with speed and accuracy.
- Images (TIFF, JPEG, MrSID) can be geo-referenced, joined, and clipped.
- Use TIFF or JPEG images to guide on-screen digitizing and to enhance
presentation.
- Boundary conditions and material properties from data layers can be assigned
to your model using GIS overlay operations.
- Coordinate System Conversions - Convert data between geographic and planar
coordinate systems.
- Control mesh/grid density and type by assigning properties to simple GIS
objects.
- Create observation points/cross sections for review and calibration of your
model output.
Model Coupling/Steering
Many of the tasks performed as part of a numerical simulation are repetitious
and time consuming. For example, a single project generally involves running the
model many times in a "warm up" or "spin down" mode. To make this type of
process easier, a tool referred to as the Steering Module. The main objectives
of the Steering Module are to:
- Simplify data sharing between models
- Monitor model runs
- Save time by automating repetitive user tasks
- Achieve more accurate results from models.
The tasks the steering module performs can be classified in two main groups.
These include single model control, and multiple model coupling. The control
channels currently available in the Steering Module are:
RMA2 Spin Down
- FESWMS Spin Down
- ADCIRC<->STWAVE Interaction
- M2D<->STWAVE Interaction
- RMA2<->SED2D Interaction
Coastal Circulation/Wave Modeling
SMS supports coastal circulation modeling with advanced finite-element and finite-difference models. You can choose which is better for your needs:
- ADCIRC - ADCIRC (ADvanced CIRCulation Multi-dimensional Hydrodynamic Model)
is a latest-generation multidimensional model based on the solution of the
generalized wave equation formulation of the governing equations on a highly
flexible unstructured grid.
- M2D - The hydrodynamic circulation model M2D is a two-dimensional,
finite-difference numerical approximation of the depth-integrated continuity and
momentum equations.
- TUFLOW - TUFLOW is a computational engine that provides two-dimensional (2D)
and one- dimensional (1D) solutions of the free-surface flow equations to
simulate flood and tidal wave propagation.
Wave modeling is also supported by SMS. Once again, finite-difference or finite-element models are available. These models can analyze wave action to predict wave height and velocity:
- STWAVE - STWAVE (STeady State Irregular WAVE Model) is a model that is
computationally efficient steady state spectral wave energy propagation model.
- CGWAVE - CGWAVE models harbor response taking into account outside sea
state, harbor shape and man-made structures (i.e., piers, breakwaters, naval
vessels). It is a forecasting and nowcasting tool used in coastal and military
planning and civil engineering.
- BOUSS2D - BOUSS-2D is a comprehensive numerical model for simulating the
propagation and transformation of waves in coastal regions and harbors based on
a time-domain solution of Boussinesq-type equations.
- WABED - Wave-Action Balance Equation with Diffraction model. The WABED model
is a nearshore wave transformation model capable of representing wave
diffraction and reflection.
Interaction between waves and currents can be modeled using the Steering Module
described above to couple a wave model with a circulation model. The most
popular combination is ADCIRC - STWAVE coupling. This allows you to run the
models together and find out how waves are affecting circulation!
River Modeling
River hydrodynamics can be modeled with SMS using one of several 2D models,
including FESWMS, RMA2, HIVEL2D. The TUFLOW model engine is capable of
representing a river system as 1D and 2D domains within SMS too!
River models will allow you predict water depth and velocity in complex
waterways including bays, estuaries, and river reachs. Natural and man-made
conditions can be simulated in unprecedented detail using the SMS pre and post
processing tools.
Water Quality/Sediment Transport Modeling
In addition to hydrodynamics, you will often need to analyze pollutant and/or sediment transport in your waterway system. There are 2 models supported in SMS that couple with RMA2 to add the capability you will need:
- SED2D - A sediment transport numerical model that has the ability to compute sediment loadings and bed elevation changes when supplied with a hydrodynamic solution computed by RMA2.
- RMA4 - A constituent migration modeling code that has the ability to compute constituent concentrations and dispersion when supplied with a hydrodynamic solution computed by RMA2.
Graphical User Interface
Thanks to the graphical tools of SMS, with standard MS Windows functionality,
building models and viewing results is very easy and intuitive. All modeling
parameters are entered through interactive graphics and easy-to-use dialog
boxes. The software is well-suited for the construction of large, complex meshes
(several thousand elements) of arbitrary shape. A finite element mesh of a
simple region can be constructed within a few minutes. Meshes of more complex
regions, which normally would take days or weeks to construct manually, can be
constructed within a few hours. Mesh generation errors are easily detected
during mesh construction, and can be corrected within minutes. Existing digital
elevation models can be imported and used as background data to generate
elevations for the model.
Graphics and Visualization
SMS is a powerful graphical tool for model creation and visualization of
results. Models can be built using digital maps and elevation models for
reference and source data. During the model building process, the graphical
representation of the model allows quick review and presentation of your work.
Fully 3D views, with contouring and shading, of your model allow anyone to see
and understand the domain and parameters of your analysis.
Analysis results from any of the models in SMS can be output or displayed graphically using a variety of plots, including vector plots, contour plots, color-shaded contour plots, and time-history plots. Contour plots and color-shaded contour plots of water surface elevation, velocity, discharge, contaminant concentration, and bed scour and deposition can easily be generated for any of the computed time-steps. Time-history plots can be requested at any location to illustrate fluctuations in water surface elevation, velocity, discharge, contaminant concentration, and bed elevation. A data set calculator is provided, allowing the user to perform comparisons between analysis models—such as displaying the difference in water surface elevations and flow velocities due to a change in the operation of a flood gate.
Both steady-state and transient solutions can be shown animated (as if viewing a
movie) using either particle trace, vector, or contour animation. For
steady-state solutions, particle trace animation allows the user to clearly see
the inherent flow patterns in the mesh (see image below). For transient
solutions, vector and contour animation allows the user to observe how water
surface elevation, velocity, discharge, contaminant concentration, and bed
elevation vary with time (see below).
Flow Trace Animation
Transient Model Animation
SMS Models
Numerical models are programs that are separate from SMS that are used to run an
analysis on a model. The models can be built in SMS, and then run through the
numerical model program. SMS can then read in and display the results of the
analysis. SMS also has the option of using a "model wrapper" to run the model
and display real-time results of during the model simulation.
The following numerical models are currently supported in SMS. Each model is included with the SMS installation (model executable files and documentation) and is fully linked with the SMS software.
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ADCIRC
A 2D, depth-integrated, barotropic time-dependent long wave, hydrodynamic
circulation model. ADCIRC can be applied to deep ocean, continental shelves,
coastal seas, and small-scale estuarine systems. |
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TUFLOW
TUFLOW is a computational engine that provides two-dimensional (2D) and one- dimensional (1D) solutions of the free-surface flow equations to simulate flood and tidal wave propagation. |
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BOUSS-2D
A comprehensive numerical model for simulating the propagation and transformation of waves in coastal regions and harbors based on a time-domain solution of Boussinesq-type equations. |
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HIVEL2D
Developed by the USACE, HIVEL2D is a two-dimensional model used to analyze high velocity flow. |
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WABED
The WABED model is a nearshore wave transformation model capable of representing wave diffraction and reflection. |
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M2D
A 2D, finite-difference hydrodynamic circulation model intended for analysis of
coastal areas. |
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CGWAVE
A wave model that can simultaneously simulate the effects of refraction,
diffraction, reflections by bathymetry and structures, dissipation due to
friction and breaking, and nonlinear amplitude dispersion. |
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RMA2
A hydrodynamic modeling code from the USACE that supports 2D subcritical flow
analysis, including wetting and drying and marsh porosity. |
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FESWMS
A hydrodynamic modeling code from the FHWA that supports both super and
subcritical flow analyses, including area wetting and drying. |
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RMA4
RMA4 can be applied to represent the transport of a contaminant, salinity
intrusion, or tracking DO and BOD in a 2D system. |
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GENESIS
A shoreline response numerical modeling system. The model is adopted as the
official shoreline change model of US Army Corps of Engineers. Accounts for
shoreline change by longshore sediment transport gradients. |
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SED2D
A sediment transport model with the ability to compute sediment loading and bed elevation changes when supplied with a hydrodynamic solution computed by RMA2. |
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HYDRO AS-2D
HYDRO AS-2D performs 2D modeling of bodies of water. The procedure integrated in HYDRO AS-2D is based on the numerial solution of the 2D current equations with Finite-volume-Discretization. |
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STWAVE
A wave model simulates wave refraction and shoaling, wave breaking, diffraction, wave growth because of wind input, wave-wave interaction and white capping. |
SMS Modules
The SMS interface is separated into several modules; these modules contain tools
that allow manipulation and model creation from different data types. The
modules of SMS are:
- Map module
- Mesh module
- Cartesian grid module
- Boundary fitted grid module
- Scatter point module.
Map Module
The Map Module in SMS allows you to use GIS or CAD data, as well as TIFF or JPEG image data, to create and enhance visualization of your surface water models.
Images (such as USGS quad maps or aerial photographs) can be used in SMS as a
reference for digitizing features in your model or as a backdrop to enhance
model presentation. With GIS or CAD data, or data you have digitized yourself in
SMS, you can assign parameters and boundary conditions to your model in a quick
and intuitive manner. SMS will automatically generate a mesh or grid network and
assign parameters/boundary conditions from your Map Module data. This greatly
reduces the time and effort required for model building, allowing you to focus
on analysis and calibration with your model.
The Map Module also allows you to set up observation points and cross sections where results from a numerical model can be compared to data collected in the real world. Further, reports and statistical analysis can be generated from these observation/calibration tools.
Mesh Module
The Mesh Module is used to construct 2D finite element meshes of rivers, estuaries, bays, wetland areas, or coastal regions. SMS includes a sophisticated set of mesh generation and editing tools to handle complex modeling situations. In SMS, 2D meshes are used as the basis for analysis for:
TABS (RMA2, RMA4, SED2D)
HIVEL-2D - supercritical flow model
FESWMS - FHWA commissioned hydrodynamic model
ADCIRC - coastal circulation model
CGWAVE - wave energy model
After an analysis, output data at each node
of the mesh can be used to generate contour, fringe and vector plots to
represent the solution. Multiple time steps from time variant solutions can be
strung together to form an animation of the dynamic solution. SMS also generates
animations of steady state vector functions such as flow velocity.
Cartesian Grid Module
The 2D Cartesian Grid Module contains tools used to construct 2D Cartesian finite difference grids. These grids consist of cells aligned with a rectilinear coordinate system. The tools provide a fast, efficient method for creating such grids, populating them with data and running a numerical model. The models that are supported in the Cartesian Grid Module are:
STWAVE - wave energy model
M2D - hydrodynamic circulation specifically adapted for coastal zones.
Analysis results from these model can be displayed using the tools in the Cartesian Grid Module to create contour, fringe and vector plots to represent the solution. Multiple time steps from time variant solutions can be strung together to form an animation of the dynamic solutions as well.
Boundary-Fitted Grid Module
The Boundary Fitted Grid Module is used for pre- and post- processing of 2D and 3D extracted boundary fitted grids. These grids consist of rows and columns of cells. Unlike Cartesian Grids, the cells in boundary fitted grids can have any quadrilateral shape and therefore are not necessarily aligned with the x/y cartesian directions. Because of this, the grid better fits the boundary of the model domain. In SMS, the Boundary Fitted Grid Module is used to create simulations for use with CH3D and ICM.
Scatter Point Module
The Scatter Point Module is used to interpolate from groups of scattered data points to the other data types (i.e., meshes and grids). SMS supports three interpolation schemes including linear, natural neighbor and inverse distance weighted. The module is also used to view and edit survey data (i.e. SHOALS data).
Interpolation can be used to provide initial conditions, compare the results of overlapping meshes, or to verify a solution. This capability in SMS allows scattered data to be applied to any mesh or grid that has been constructed for modeling in SMS.
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