Case 20: Water - Flow at a Junction
Reference: 2500 Solved Problems in Fluid Mechanics and Hydraulics, 1989, McGraw-Hill, Jack B. Evett, Ph. D., Cheng Liu, M.S., Page 339, Example problem 13.23
Pipe Flow Expert File: Case_20_Water_Flow_At_A_Junction.pfe
Problem Description:
Four cast iron pipes connect at a junction.
The pressure at the end of each pipe which is not connected to the junctions are:
P1 = 800 kPa
P2 = 400 kPa
P3 = 600 kPa
P4 = 200 kPa
The internal roughness of the cast iron pipe has been set to 0.250 mm to simulate the friction factor of 0.0294 assumed in the published text.
Calculate the flow rate in each individual pipe.
Calculate the pressure at the junction.
Fluid Data: Water at 10° C (assumed).
Result Comparison:
|
Data Item |
Published data |
Pipe Flow Expert |
|
Q1 Flow rate (m³/s) |
+0.0181 |
+0.0182 |
|
Q2 Flow rate (m³/s) |
-0.0104 |
-0.0104 |
|
Q3 Flow rate (m³/s) |
+0.0104 |
+0.0104 |
|
Q4 Flow rate (m³/s) |
-0.0181 |
-0.0182 |
|
Pressure at Junction (kPa) |
500 |
500.0000 |
Commentary:
The published data and the calculated results compare well.
Flow to the junction has been indicated by a positive flow rate value.
Flow away from the junction has been indicated by a negative flow rate value.
Note: The flow balance to and away from the junction is maintained.