GEO_geometry_hrprism(): Hydraulic radius of a prismatic open-channel

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Calculate the hydraulic radius of a prismatic open-channel.

©WETpython, 2015

\begin{equation} H_r = \frac{A}{W_P}\end{equation} 

Where,

$H_r$, hydraulic radius of a prismatic open-channel , $m$

$A$, area of a prismatic open-channel » GEO_geometry_aprism(), $m^2$

$W_p$, wet perimeter of a prismatic open-channel » GEO_geometry_wpprism(), $m$

This function is a applied to trapezoidal, triangular a rectangular sections:

for a trapezoidal section: $B \not= 0, m_l \not= 0, m_r \not= 0$

for a triangular section: $B = 0$

for a rectangular section: $m_l = m_r = 0$

Module: Geometry

Function: GEO_geometry_hrprism(y, b, ml, mr)

Parameters:

• y, flow height, m;
• b, channel bottom , m;
• ml, slope of left embankment (1/ml);
• mr, slope of right embankment (1/mr)

Sample code:

from Geometry import *

y = 0.75 #(m)
b = 1.5 #(m)
ml = 1.5
mr = 3.0

rh = GEO_geometry_hrprism(y, b, ml, mr)
print ("Rh:", rh,"m")

Result:

Rh: 0.4576418677170607 m