HP-41 Programs
08-09-2015, 07:16 PM
Post: #1
 Tim Walker Junior Member Posts: 2 Joined: Aug 2015
HP-41 Programs
Hi: I' am looking for a program to calculate the volume of laminar flow of water in a pipe using Manning's formula. Inputs would be: Slope of the pipe, diameter of the pipe, Manning's roughness factor, and measured depth of flow. Barcode of the program would be great, or mag cards (I could provide the cards if I can find some), or even the program listing if that is all you have. Email me direct at W1GIG@att.net Thanks, Tim
08-09-2015, 07:44 PM
Post: #2
 Thomas Klemm Senior Member Posts: 1,447 Joined: Dec 2013
RE: HP-41 Programs
But as far as I remember the slope of the pipe wasn't involved. Maybe it's still useful for you.
Some of the attachments in my posts contain the barcode of the programs. Thus it should be easy for you to load them into your calculator.

Kind regards
Thomas
08-11-2015, 07:32 PM
Post: #3 SlideRule Senior Member Posts: 999 Joined: Dec 2013
RE: HP-41 Programs
Circular X-Section, Partially Full, Gravity Flow, SOLVER approach

Problem
A 4-foot-diameter finished concrete pipe is laid at a slope of 0.2%. The water depth is 3 feet. Calculate the flow rate and flow velocity using Manning's equation.

Solution

Step 1. Calculate the flow rate (ft3/sec).
- Q for Partially Full Circular X-Section
Q=C÷N((0.5×SIN(ACOS((H−D÷2)÷(D÷2))×2)+π(360−ACOS((H−D÷2)÷(D÷2))×2)÷360)
×(D÷2)^2)^(5÷3)÷(π×D(360−ACOS((H−D÷2)÷(D÷2))×2)÷360)^(2÷3)×S^0.5

Where:
Q = flow rate (ft3/sec, m3/s)
C = 1.49 for English units, 1 for Metric units
N = Manning roughness coefficient
H = depth of water (ft, m)
D = diameter of pipe (ft, m)
S = slope of energy line (decimal)

Step 2. Compute the velocity of flow.
- V for Partially Full Circular X-Section
V=C÷N((0.5×SIN(ACOS((H−D÷2)÷(D÷2))×2)+π(360−ACOS((H−D÷2)÷(D÷2))
×2)÷360)×(D÷2)^2)÷(π×D(360−ACOS((H−D÷2)÷(D÷2))×2)÷360)^(2÷3)×S^0.5

Where:
V = velocity of flow (ft/sec, m/s)
C = 1.49 for English units, 1 for Metric units
N = Manning roughness coefficient
H = depth of water (ft, m)
D = diameter of pipe (ft, m)
S = slope of energy line (decimal)

see attached PDF for Equations & Illustrations.
[attachment=2421]
BEST!
SlideRule
08-18-2015, 03:55 PM
Post: #4
 Tim Walker Junior Member Posts: 2 Joined: Aug 2015
RE: HP-41 Programs
To Sliderule:

Thanks again!

Tim Walker
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