Solving For Mass Flow Rate of Two Water Jets

Click For Summary
SUMMARY

The discussion focuses on calculating the mass flow rate of two water jets using Bernoulli's equation, the Mass Continuity equation, and the Momentum equation. The user initially assumed equal areas for both jets and derived the equation Q = A(va + vb) but encountered three unknowns (A, va, and vb) with only two equations available. A suggestion was made to consider the vertical component of the jet's weight to aid in the calculations, emphasizing the need to clarify the definitions of variables va and vb as the velocities of jets A and B, respectively.

PREREQUISITES
  • Understanding of Bernoulli's equation
  • Familiarity with the Mass Continuity equation
  • Knowledge of the Momentum equation
  • Basic concepts of fluid dynamics
NEXT STEPS
  • Review the application of Bernoulli's equation in fluid dynamics
  • Study the Mass Continuity equation in the context of multiple fluid jets
  • Explore the Momentum equation and its implications for fluid flow
  • Investigate the effects of vertical components in fluid dynamics scenarios
USEFUL FOR

Students and professionals in fluid dynamics, mechanical engineers, and anyone involved in calculating mass flow rates in fluid systems.

zewei1988
Messages
21
Reaction score
0

Homework Statement


I am supposed to find the mass flow rate for the two resulting water jets.


Homework Equations


Bernoulli's equation
Mass Continuity equation
Momentum equation


The Attempt at a Solution


I've assumed the two areas for jet A and B to be equal, and used mass continuity equation to form:

Q = A( va + vb)

and used momentum equation to form

0 = -Qava + Qbvb - Qv

But I have 3 unknowns (A, va, and vb) but only 2 equations, so I'm stuck. Can anyone help me?
 

Attachments

  • Untitled1.png
    Untitled1.png
    54.3 KB · Views: 501
Physics news on Phys.org
hi zewei1988! :smile:

i don't understand what your va and vb are :confused:

there's no pipes there, it's just the jet spreading out all over the plate

anyway, since the plate's weight is vertical, and is being balanced, shouldn't you start by finding the vertical component of the https://www.physicsforums.com/library.php?do=view_item&itemid=53" of the jet?
 
Last edited by a moderator:
Sorry. my Qa and va are volume flow rate and velocity in jet A, Qb and vb are volume flow rate and velocity in jet B.

I've already solved part (i) of the question. Since the velocity of water jet in A and B are horizontal in direction, i felt there was no need to consider the weight in solving for mass flow rate in A and B.
 

Similar threads

  • · Replies 56 ·
2
Replies
56
Views
6K
  • · Replies 5 ·
Replies
5
Views
6K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 3 ·
Replies
3
Views
6K
  • · Replies 13 ·
Replies
13
Views
11K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 6 ·
Replies
6
Views
4K