Flow Distribution Across the Cross Section
Flow distribution across the cross section will be calculated when all the
variables in the uniform flow equation are prescribed. In addition, flow
distribution will be calculated after the uniform flow equation is solved for an
unknown variable. A conveyance weighted discharge, Qi, is calculated for each
panel using the following equation:
C A Ri
Qi = Q i i
Equation 2-33
ΣC
Ri
i Ai
where
Q = total discharge
C = Chezy coefficient
A = area
R = hydraulic radius
i = panel number
Bottom Width Calculation-Fixed Bed
This option allows bottom width to become the dependent variable in the
uniform flow equation:
W = f (Q, n, D, z, S)
Equation 2-34
where
Q = water discharge
D = water depth
z = side slopes of the channel
n = n-value
S = energy slope
This bottom width calculation is strictly a solution of the uniform flow equation
for a fixed bed and does not consider sediment transport requirements. This
option can only be used when a trapezoidal channel is specified on a CT-record.
The compound channel may have up to 3 trapezoidal-shaped templates. The
solution technique begins by sizing the low flow channel first, then solving for
the main channel and then the overbank channel.
28
Chapter 2
Theoretical Basis for SAM.hyd Calculations
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