Sudden Expansion: Difference between revisions

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== Model Setup ==
== Model Setup ==
[[Image:Bump_Grid.png|thumb|right|600px|  Figure 1. Computational grid.]]
[[Image:Sudden_Expansion_Grid_V2.png|thumb|right|600px|  Figure 1. Computational grid.]]
The computational domain is 25 m  long and has a constant grid resolution of 0.1 m. A flux boundary  condition is specified at the inflow boundary and a constant water level  boundary condition is applied to the downstream boundary. An adaptive  time between 0.1-10 seconds is applied.  
The computational domain is 25 m  long and has a constant grid resolution of 0.1 m. A flux boundary  condition is specified at the inflow boundary and a constant water level  boundary condition is applied to the downstream boundary. An adaptive  time between 0.1-10 seconds is applied.  



Revision as of 00:32, 15 December 2010

UNDER CONSTRUCTION

Setup

The spatial domain consists of a rectangular

  (1)

where is the bed elevation and is the horizontal distance.

Table 1. General Settings for Flow over a Bump

Parameter Value
Discharge 0.18 m^3/s
Downstream water level 0.33 m
Bottom friction None

Model Setup

Figure 1. Computational grid.

The computational domain is 25 m long and has a constant grid resolution of 0.1 m. A flux boundary condition is specified at the inflow boundary and a constant water level boundary condition is applied to the downstream boundary. An adaptive time between 0.1-10 seconds is applied.


Results

Figure 2. Comparison of analytical and calculated water surface elevations and bed elevations.

A comparison between the analytical solution for water levels is compared to the calculated water levels in Figure 2. As shown in the goodness of fit statistics, the model results agree well with the analytical solution. The minimum water level is captured well, however there is a small shift in the location of the water level drop over the bump toward the downstream direction.


Table 2. Goodness of fit statistics for the water elevation

Statistic Value
RMSE 0.0074 m
RMAE 0.0068 m
R^2 0.991
Bias 0.0017 m


References

  • Caleffi, V., Valiani, A., and Zanni, A. (2003). "Finite volume method for simulating extreme flood events in naturalchannels," Journal of Hydraulic Research, 41(2), 167-177.

Test Cases

Documentation Portal