TEST HEAD CASE
This test case checks the ability of a model to represent 1) simplified alongshore transport, 2) implementation of open boundary conditions, and 3) resuspension, transport, and deposition of suspended-sediment. This case is based on Signell and Geyer (1991).
The model domain is open at the east and west ends, has a straight wall at the north end, and a parabolic headland along the south wall.
Model Parameter Variable Value Length (east-west) l 100000 m Width (north-south) w 50000 m Depth h 20 m
Single grain size on bottom:
Model Parameter Variable Value Size D50 0.1 mm Density ρs 2650 kg/m3 Settling Velocity ws 0.50 mm/s Critical shear stress τc 0.05 N/m2 Bed thickness bed_thick 0.005 m Erosion Rate E0 5e-5 kg/m2/s
- Depths increase linearly (slope = 0.0067) from a minimum depth of 2 m at all alongshore points from the southern land boundary offshore to a maximum depth of 20 m at a point 3 km offshore. Offshore of 3 km there is a constant depth of 20 m.
North, south = walls with no fluxes, no friction
South wall = parabolic headland shape
Flow and elevation at western boundary is imposed.
Flow on eastern boundary is open radiation condition, or water level based, or Kelvin wave solution.
Flow and elevation, eastern/western boundaries:
- Reference velocity
- Reference water level
- Wave period hours (43200 seconds)
- Wave length
- Wave number
For each point along the boundary at time :
Sediment flux calculated by model
Surface = free surface, no fluxes
Output (ASCII files suitable for plotting)
After 10 days :
Von Karman's constant
Dynamic viscosity (and minimum diffusivity)
Simulations were conducted for 3.0 days. Final bed thickness is shown in Figure 1.