Woods Hole Coastal and Marine Science Center
Provisional Pages: Work in Progress
Test Case 1
Channel Flow
Domain
Bottom Sediment
Forcing
Boundary Conditions
Output
Physical Constants
Results
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This case provides a fundamental check of the ability of a model to 1) represent a simple flow, 2) flux material from the bed, and 3) develop a suspended-sediment profile.
Domain
The model domain is a long, narrow rectangular box.
Length l = 10,000 m
Width w = 1000 m
Depth h = 10 m
Flat bottom Fresh water, T = 20° C Salinity = ‰
Bottom Sediment
Single grain size on bottom
Size (D50) = 0.15 mm (fine sand)
Density ρs = 2650 kg/m³
Settling velocity = 0.001 m/s
Critical shear stress τc= 0.05 N/m²(0.5 dynes/cm²)
Fractional bed concentration (1-porosity) = 0.90
Infinite supply of sediment (no erosion, no armoring)
Forcing
Inflow boundary condition only
No Rotation (f z0)
No wind
No heating/cooling
Boundary Conditions
Inflow maintained as steady flow, depth-mean flow <u> = 1 m/s
Outflow = open
Sides = walls with no fluxes, no friction
Bottom roughness z0 = 0.005
Sediment flux calculated by model
Surface = free surface, no fluxes
Output (ASCII files suitable for plotting)
Velocity profile at x = 8000 m
Suspended sediment profile at x = 8000 m
Time series of net rate of sediment flux from bed and/or concentration at specified levels
Physical Constants
Gravitational acceleration g = 9.81 m/s²
Von Karman's constant κ = 0.41
Water density ρw = 998 kg/m³
Dynamic viscosity (and minimum diffusivity) ν = 1e-6 m²/s
Note
If a model incorporates physical constants that differ from these, and/or automatically calculates some values specified here, please specify the values used.
Results
Solution to Test Case 1: Straight Flume
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These pages are for communication among a group of researchers studying experimental methods of modeling and visualizing natural systems using digital (numerical) techniques. The methods and models discussed are in preliminary, developmental, stages and may be incorrect. The pages will be changed or removed without warning. The U.S. Geological Survey makes no representation as to the accuracy, correctness, or utility of any data, model, model results, or technique associated with these pages.
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