Solving the Network of Pipes: Two Possible Answers?

  • Thread starter Thread starter foo9008
  • Start date Start date
  • Tags Tags
    Network Pipes
Click For Summary

Homework Help Overview

The discussion revolves around a network of pipes where participants are exploring different approaches to solving flow equations. The original poster presents two methods for calculating flow rates and head at a junction, leading to different results.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss two equations for flow rates: one suggesting that the flow into a junction equals the sum of flows out, and another proposing a different relationship. Questions arise about the validity of obtaining two different answers and whether both methods can be correct.

Discussion Status

The conversation is ongoing, with participants seeking clarification on the correctness of their approaches. Some express uncertainty about the implications of having two answers and whether assumptions made in the problem setup are valid.

Contextual Notes

Participants note the requirement to find a condition where the net flow (delta Q) equals zero, indicating a balance between inlet and outlet flows. There is also mention of an assumption regarding the height of the junction relative to a datum, which is questioned for its correctness.

foo9008
Messages
676
Reaction score
4

Homework Statement


in this network of pipe , the author make the attempts to solve it using ( Q1 = Q2 + Q3) , so delta Q = Q1 -(Q2 +Q3) , the value of head of junction that he gt is 25.2 , with delta Q = (3x10^-3) ( not shown in the working)

Homework Equations

The Attempt at a Solution


however, when i tried to solve it using ( Q1 + Q2 = Q3) , which means ( Q1 +Q2 - Q3 ) , thae ans that i gt is hj = 28 , with delta Q = 0.07 [/B]

P/s : we have to find the delta Q = 0 for the ans so that water from inlet = water from outlet
so , question has two ans depending on the flow of water ? or i am wrong ?
 

Attachments

  • 178.PNG
    178.PNG
    18.4 KB · Views: 493
  • 179.PNG
    179.PNG
    19.7 KB · Views: 443
  • 180.PNG
    180.PNG
    21.7 KB · Views: 474
  • 181.PNG
    181.PNG
    12.9 KB · Views: 469
  • 182.PNG
    182.PNG
    12.5 KB · Views: 501
Physics news on Phys.org
OiFq3mL.png

zsrSg6N.png
 
is it wrong to have 2 answer for such question ,
i find it work by using ( Q1 = Q2 + Q3) and ( Q1 + Q2 = Q3)
 
Anyone can comment ?
 
bump
 
deleted
 
Bump
 
i have done this question in 2 ways , which is ( Q1 - (Q2 + Q3) ) and ( Q1 +Q2 - Q3 ) which is correct ? or both are correct ? please refer to post 1
 
pls ignore the question i posted above ...
now , i have new question with the same figure..
from the diagram , we know that the junction is lower than the pipe at B . why the author want to make an assumption that the junction is located at 20m from the datum ? is it correct to do so ?
 
  • #10
can i start a new thread and delete this thread ? how to delete this thread ??
 

Similar threads

Can Water Flow in Multiple Directions in a Network of Pipes?
  • · Replies 15 ·
Replies
15
Views
2K
How Does the Q1=Q2+Q3 Concept Explain Flow in Branch Pipes?
  • · Replies 21 ·
Replies
21
Views
3K
Thermal physics -- Latent heat melting ice
  • · Replies 12 ·
Replies
12
Views
3K
Why is water unable to flow from A and B to C in a branching pipe system?
  • · Replies 7 ·
Replies
7
Views
2K
Calculating Two Unknown Charges from a Tripole
  • · Replies 3 ·
Replies
3
Views
4K
Three charges located on a straight line
  • · Replies 7 ·
Replies
7
Views
10K
Help with Electric Forces Problem and Equilateral Triangles
  • · Replies 3 ·
Replies
3
Views
10K
Electrostatics (four equal point charges)
  • · Replies 14 ·
Replies
14
Views
2K
Infinite chain of alternating charges (+/-)
  • · Replies 29 ·
Replies
29
Views
4K
Coulomb's Law, finding acceleration direction
  • · Replies 3 ·
Replies
3
Views
2K