The
program CHAN may be used to model unsteady flows (such as surges), floods and storm runoff in
a system of channels, streams, sewers, tunnels and other constructed
water conveyance structures, and in closed conduits flowing partially
full. The unsteady flow may be produced by runoff
from
precipitation, i.e., rainfall, snowmelt, etc., failure of levees, dams,
and other control structures, or opening and/or
closing of control
gates. In addition, the program may be used to compute the variation of
air pressure above the freewater surface in partially full closed
conduits and air inflow and outflow through vent shafts during the
transient conditions.
The
program CHAN is written in FORTRAN for use on IBM or
IBMcompatible
personal computers. The channel system may be a series or a branching
system.
With the current DIMENSION statement, systems
having up to 100 channels, 15 gates, 15 inflow and outflow hydrographs,
15 weirs, 5 upstream and 5 downstream constantlevel reservoirs. Each
channel may be divided into as many as 1000 equallength reaches.
To facilitate data input, free format is used. Several
options are available for printing the program output. The
computed flow conditions may be stored for postprocessing and plotting
by using any other program.
Either
English or SI units may be used for the system parameters.
The
program computes initial steadystate conditions by numerically
integrating the gradually varied flow equation. The
explicit finitedifference (Lax diffusive scheme) is used to compute the
unsteady flows. Control devices and other appurtenances
are simulated by using procedures outlined in OpenChannel Flow, 2^{nd}
ed., by M. H. Chaudhry, Springer, New York, NY., 2008. The software has
been verified by comparing the computed results with those measured in
the laboratory or in the field.

Surge
wave in Seton Canal
Seton Canal: Comparison of Computed and
Measured Surge Levels
