SUNTANS (Stanford Unstructured Nonhydrostatic Terrain-following Adaptive Navier-Stokes Simulator)
Criterion | Explanation |
General Description | SUNTANS is an open-source 3-D circulation model developed at Stanford University that computes flows on an unstructured grid using a finite-volume method. SUNTANS is highly parallelized and designed to be used on large parallel computing clusters. SUNTANS is similar to the 3-D unstructured-grid UnTRIM model. It includes algorithms for sediment transport and surface wave effects on bottom stresses and flows. Various grids have been created for parts and the entirety of the Bay–Delta in the context of applications to the South Bay Salt Pond restoration as well as for detailed flow modeling in the Delta. |
Model Domain | The model domain is flexible and can be specified by the user, and can include coastal, estuarine, lakes and river areas. |
Developer | Stanford University |
Hardware computing requirements | SUNTANS is highly parallelized and designed to be used on large parallel computing clusters. |
Code language | C |
Original application | SUNTANS is an unstructured-grid tool that adaptively simulates multiscale physics in the coastal ocean; specifically designed for coastal and estuarine processes. Early applications were to the San Francisco bay and Snohomish River estuary. |
Public/proprietary and cost | The model source code is open source. |
Physically or empirically based | Physically based |
Mathematical methods used | SUNTANS computes flows on an unstructured grid using a finite-volume method, and implements two key approaches: (1) a semi-implicit free surface; and (2) a fractional step method to efficiently calculate the effects of nonhydrostatic pressures. |
Input data requirements | Model developers recommend the grid generation package GAMBIT from Fluent, Inc. All input files are ASCII text files. Input data includes:
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Outputs | A standalone GUI is provided to view results (but cannot output results to standard figure file formats). Model outputs are provided in ASCII or binary files. Model output includes: free surface, velocity vectors, salinity, temperature, nonhydrostatic pressure, eddy viscosity, scalar diffusivity, water depth. |
Pre-processing and post-processing tools | Model developers recommend the grid generation package GAMBIT from Fluent, Inc. A standalone GUI is provided to view results (but cannot output results to standard figure file formats). |
Representation of uncertainty | Uncertainty is not represented. |
Prevalence | The model is used by the academic community, therefore most or all known applications are in the peer-reviewed literature. |
Ease of use for public entities | SUNTANS is highly parallelized and designed to be used on large parallel computing clusters, therefore the barrier is high for widespread public use. |
Ease of obtaining information and availability of technical support | The model is maintained on Github which acts as a user forum; there is no formal help desk. The Github repository does not have an active user base. |
Source code availability | The model source code is open source. |
Status of model development | The model is available for immediate use. The following features were recently implemented in SUNTANS: a suspended sediment transport model and a spectral wave model to include the effects of wave-driven currents and bottom stresses. The following features are under development: simulation of flows in salt-marsh estuaries with a marsh vegetation drag module along with a culvert module; and the method of subgrid bathymetry, whereby bathymetry data at a resolution that is finer than the mesh are incorporated into the solution without increasing the resolution of the underlying computational mesh. |
Challenges in integration | Although the model is open source, it is designed as a research tool and is not well documented for public use. The model is highly parallelized and designed to be used on large parallel computing clusters, therefore the barrier is high for widespread public use. |
References
Y.-J. Chou, K. S. Nelson, R. C. Holleman, O. B. Fringer, M. T. Stacey, J. R. Lacy, S. G. Monismith, and J. R. Koseff, 2018, "Three-dimensional modeling of fine sediment transport by waves and currents in a shallow estuary", J. Geophys. Res.-Oceans., 123, doi:10.1029/2017JC013064
Hsu K, Stacey MT, Holleman RC. 2013. Exchange between an estuary and an intertidal marsh and slough. Estuaries Coasts 36:1137–1149. doi: http://dx.doi.org/10.1007/s12237-013-9631-2
Wolfram PJ, Fringer OB, Monsen N, Gleichauf K, Fong D, Monismith SG. 2016. Modeling intrajunction dispersion at a well-mixed tidal river junction. Hydraul Eng 42(8). doi: http://dx.doi.org/10.1061/(ASCE)HY.1943-7900.0001108
Stacey, M., Holleman, R., & Gross, E. S., 2011. Test Applications of High Resolution 3- Dimensional Hydrodynamic Model (SUNTANS) to San Francisco Bay. Contribution No. 638. San Francisco Estuary Institute, Oakland, California.