Since 1989, the NCCHE has been supported by USDA Agricultural Research Service by means of funds appropriated by the U.S. Congress, with a mandate to develop state-of-the-art numerical models for simulating flow and sedimentation processes in the natural environment. Since then a suite of 1D, 2D and 3D computer models have been developed, verified, refined, validated, documented and applied to simulate a variety of free surface flow and sediment transport related phenomena.
CCHE1D is available for general release and CCHE2D is currently in beta testing. They are available for testing/use free of charge from our download page.
Other NCCHE models, such as CCHE3D and CCHE-FLOOD, or extensions of CCHE1D or CCHE2D, such as CCHE-WQ, CCHE-TIDE, CCHE-COAST, etc., can also be used free of charge, by collaborating with NCCHE researchers.
CCHE1D is a software package for simulations of one-dimensional unsteady flows and sediment transport in dendritic channel networks. The software package has been designed to facilitate the combined modeling of watershed and channel processes.
CCHE1D’s hydrodynamic model includes special procedures for the computation of flow across hydraulic structures like culverts, low and high-drop structures, bridge crossings, and measuring flumes.
The sediment transport module computes non-equilibrium transport of non-uniform sediment mixtures. It has been designed for long-term predictions of channel morphological changes, and it can be used to evaluate the effectiveness of in-channel remedial and control structures on the sediment yield.
The CCHE1D water quality module simulates the transport and fate of nutrients and other pollutants in channel networks, including the biogeochemical reactions that take place in the streams.
An ArcView GIS graphical interface facilitates the data management and the integration of the channel model with watershed models and other tools. It also includes a landscape analysis module that delineates the drainage network and corresponding subcatchments based on digital elevation data.
Free Software (Download)
CCHE2D is an integrated software package developed at the National Center for Computational Hydroscience and Engineering, the University of Mississippi. It is a general model for two-dimensional simulation and analysis of river flows, dam break flows, non-uniform sediment transport, morphologic processes, coastal processes, pollutant transport and water quality. These processes are solved with the depth integrated Reynolds equations, mass transport equations, sediment sorting equation, bed load and bed deformation equations. This model is based on Efficient Element Method, a collocation approach of the Weighted Residual Method. Internal hydraulic structures, such as dams, gates and weirs, can be formulated and simulated synchronously with the flow. Dry and wet capability enables one to simulate flows with complex topography with ease. Three turbulence closure schemes, depth-averaged parabolic, mixing length eddy viscosity models and k- e model, and available. The numerical scheme can handle subcritical, supercritical flows and their transition.
A Graphic User Interface (GUI) is developed for applications of CCHE2D. The GUI drives and manages simulations, it is a user friendly tool. Starting with a computational mesh, the GUI helps users to setup parameters, boundary conditions and to run the simulations and visualize the computational results. Not all of the capabilities of the CCHE2D are accessible from the GUI due to limitations of resources.
Free Software (Download)
Interactive, graphical user interfaces (GUIs) are being developed for the NCCHE flow, sediment transport, and water quality models. Each GUI provides a convenient environment for input datapreparation and model operation. They also provide advanced visualization capabilities and tools to facilitate the application of the NCCHE models toreal-life engineering problems.
Each graphical interface program has been designed to provide the most convenient set of tools for the model user. The CCHE1D interface program is integrated into ArcView GIS to facilitate the use of GIS data and to simplify integration with watershed models. The CCHE2D and CCHE3D GUIs are implemented using OpenGL to provide fast, high quality computer graphics, including the production of video animations.
Graphical interfaces for the CCHE1D and CCHE2D models are part of free software packages, and are distributed with the respective models. For more information on the research related to graphical interface programs, click here.
NCCHE has developed a complete, interactive mesh generation program to support both the CCHE2D and CCHE3D models. The program includes several techniques for the generation and optimization of structured meshes.
This graphical program allows the rapid creation of complex mesh systems. Several algebraic and numerical methods are available for the generation of boundary-fitted meshes. A novel multi-blockapproach facilitates mesh generation for complex geometries.
The NCCHE Mesh Generator is distributed as free software, and it is part of the CCHE2D modeling package. Find out more here.