|Model type||Two-dimensional finite element surface water computer program that can compute the direction of flow and water surface elevation in a horizontal plane. Also has the ability to model hydraulic structures commonly used by hydraulic engineers.|
|Developer||David C. Froehlich, Ph.D., P.E.|
|Web site||FHWA web site|
The Finite Element Surface Water Modeling System (FESWMS) consists of multiple modules used to simulate surface-water flow in a two-dimensional horizontal plane. The SMS includes an interface for the FST2DH (Flow and Sediment Transport) module of FESWMS. FESWMS is sponsored by the Federal Highway Administration. David C. Froehlich, Ph.D., P.E. originally developed FESWMS for the United States Department of Transportation Federal Highway Administration (FHWA) and the United States Geological Survey (USGS). The FHWA has continued to maintain and sponsor development of subsequent versions, which continue to incorporate features specifically designed for modeling highway structures in complex hydraulic environments.
FST2DH is the FESWMS program that performs the two-dimensional hydraulic computations in surface-water bodies. FST2DH can perform either steady state or dynamic flow modeling and provides analysis of highway crossings and structures, including bridges, culverts, weirs, roadway embankments, and drop-inlet spillways. FST2DH simulates the movement of water and non-cohesive sediments in rivers, estuaries, and coastal waters by applying the finite element method to solve steady-state or time-dependent systems of equations that describe two-dimensional depth-averaged surface-water flow and sediment transport. 
Using the Model / Practical Notes
- FESWMS Spindown Steering (Incremental Loading)
- The representation of the wind direction in the FESWMS Manual is incorrect. The corrected image is shown in the FESWMS Model Control dialog of the SMS interface.
- FESWMS known model issues
- Support Forum FESWMS with Sediment Transport Tips User Post
- Transform your mesh so it is close to the origin (0,0). Large x, y coordinates can be problematic for FESWMS.
- Verify mesh does not have incorrect elevation values (often due to extrapolation). Try looking at the mesh in a rotated view.
General Steps to build a FESWMS Model
Various sequences of steps can be used to create and edit a two-dimensional model in SMS. A suggested methodology is provided below.
- Import background data consisting of:
- Create a FESWMS coverage and define the Conceptual Model that will be used to generate the finite element mesh. See Map Module
- Define the physical boundaries of the model
- Build feature polygons within the model domain. See Build Polygons Menu
- Assign mesh types to the feature polygons and adjust the density and spacing of vertices (i.e., redistribute vertices) as necessary to achieve appropriate element shapes and sizes
- Creata an area properties coverage and assign material types. This is an optional step. The FEWSMS coverage can also be used to define material regions. See Map Module
- Generate a finite element mesh from the Conceptual Model. See Map Module
- Check the final quality of the finite element mesh and edit the mesh as needed. See 2D Mesh Module
- Designate element types (i.e., linear or quadratic; triangular or quadrilateral)
- Review the mesh quality
- Specify FESWMS element attributes (i.e., material properties) such as Manning's or Chezy roughness factors and eddy viscosity to the material types. See 2D Mesh Module
- Create nodestrings and assign model boundary conditions not included in the conceptual model. See 2D Mesh Module
- Renumber the finite element mesh.
- Specify initial conditions and model control parameters. See FESWMS Model Control
- Run the model.
- View model results. If necessary, troubleshoot error/warning messages generated during the model run and revise the model accordingly.
SMS provides a graphical interface that is designed to allow users to visualize the projects they are creating, easily modify project parameters, and view the solutions produced by the FESWMS model. See FESWMS Graphical Interface for more information.
The FESWMS Graphical Interface contains tools to create and edit an FESWMS simulation. The simulation consists of a geometric definition of the model domain (the mesh) and a set of numerical parameters. The parameters define the boundary conditions and options pertinent to the model.
The interface is accessed by selecting the 2D Mesh Module and setting the current model to FESWMS. If a mesh has already been created for a FESWMS simulation or an existing simulation read, the mesh object will exist in the Project Explorer and selecting that object will make the 2D Mesh module active and set the model to FESWMS. See the Mesh Module documentation for guidance on building and editing meshes as well as visualizing mesh results.
- Sept. 2002 - User’s Manual for FESWMS Flo2DH - Publication No. FHWA-RD-03-053 
- U.S. Department of Transportation Federal Highway Administration - Hydraulics Engineering Software Page 
- Ipson, Mark K. (2006). Analysis of the Sediment Transport Capabilities of FESWMS FST2DH. Thesis, Brigham Young University. 
- FST2DH Files
- FST2DH Graphical Interface
- FST2DH Hydraulic Structures
- FST2DH Model Control Dialog
- FST2DH Spindown
- FST2DH Sediment Transport
- FST2DH known model issues
- ^ Sept. 2002 - User’s Manual for FESWMS Flo2DH - Publication No. FHWA-RD-03-053