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Numerical Simulation of Channel Flows (Image 3)
A numerical simulation of channel flows showing water surface elevation during an ebb tide. This figure is similar to figure 2, but it shows the water surface elevation during an ebb tide. At high tide, the entire slough is inundated with sea water (see top-left pane). Then the ebb tide comes, and the water surface starts to drop, allowing the mudflats to gradually dry out (see top-right to bottom left panes). During low tides, most parts of the mudflats are dry (see bottom-right pane). In this simulation, researcher Gang Zhao used the measured bathymetry data for the mudflats. [Image 3 of 4 related images. See Image 4.]
More about this Image
Researchers Gang Zhao, Peter Ioannidis and Robert Street from the Environmental Fluid Mechanics Laboratory in the Civil and Environmental Engineering Department at Stanford University, used a 3-D numerical model--which, simply speaking, is a computer program--to study the hydrodynamics of complex channel flows.
Understanding how water flows in channels is important for engineering projects, such as flood control, channel bank erosion control, and habitats restoration. The purpose of this study was to develop a numerical model and apply it to simulate complex channel flows. To learn more about the model, visit the SUNTAN (Stanford Unstructured Nonhydrostatic Terrain-following Adaptive Navier-Stokes Simulator) website.
The research team simulated the tidal currents in Elkhorn Slough, which is about 10 kilometers long and consists of a meandering main channel and a large area of mudflat and marsh. Elkhorn Slough has the second largest tidal salt marsh in California, which provides habitat for many plants and animals. However, the size of the salt marsh at Elkhorn Slough is decreasing due in part to tidal erosion. This simulation provides high-resolution velocity distribution inside the slough, which is a key step in understanding the hydrodynamics of the slough, and is important for future habitat conservation and restoration projects.
[This research was supported in part by National Science Foundation (NSF) grant 00-87842. Computations were performed at Stanford University's Center for Computational Earth and Environmental Science. SUNTAN is sponsored in part by NSF grant 01-13111.] (Date of Image: 2005)
Credit: Michael MacWilliams, Environmental Fluid Mechanics Laboratory, Stanford University
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