Channel geometry

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Description

Compute geometry relations for trapezoidal channels.

Usage

1
channel_geom(y, B, SS)

Arguments

y

Flow depth [L].

B

Channel bottom width [L].

SS

Channel sideslope [L L^{-1}]. For a rectangular channel, SS = 0.

Details

Channel geometry relations are routinely calculated in numerical solutions of steady, gradually-varied and unsteady flows. This function is used extensively by internal procedures and is made accessible to the user for convenience.

Value

Named vector:

A

Flow area [L^2].

P

Wetted perimeter [L].

R

Hydraulic radius [L].

dAdy

Water surface width [L].

dPdy

First derivative of wetted perimeter w.r.t. flow depth.

dRdy

First derivative of hydraulic radius w.r.t. flow depth.

DH

Hydraulic depth [L].

ybar

Vertical distance from water surface to centroid of flow area [L].

Examples

1
2
channel_geom(1.71, 100, 0) # rectangular channel
channel_geom(5.79, 6.1, 1.5) # trapezoidal channel with sideslope 3H:2V