Bernoulli's Equation and tube vacuum

Click For Summary
A venturi tube creates a local vacuum downstream due to increased velocity and decreased pressure at the throat. This pressure differential induces air into a secondary opening. The application of Bernoulli's equation is valid for calculating pressure drop in the venturi tube, even for the air induction at the secondary opening, provided the vacuum is not excessively large. However, a discharge coefficient should be applied to account for non-ideal flow conditions. Understanding these principles is crucial for accurate calculations in fluid dynamics.
Great Smoky
Messages
8
Reaction score
0
I have a venturi tube and downstream of it, there is a small secondary opening at the end of the throat. This is where the local vacuum is created as the velocity increases and the pressure decreases. This difference between this pressure and the atmospheric pressure will induce air into the secondary opening. Does anybody know if I have to use another equation for the rate of air induction versus this differential pressure or will the same Bernoulli's equation for pressure drop through the venturi tube still apply? If there is another equation, do you know what it is? Thanks!
 
Physics news on Phys.org
If your vacuum is not too large (say 13.2 psia), you could apply the Bernoulli equation to this "air hole" also. You should use a discharge coefficient for the air hole since flow will not be ideal.
 
For simple comparison, I think the same thought process can be followed as a block slides down a hill, - for block down hill, simple starting PE of mgh to final max KE 0.5mv^2 - comparing PE1 to max KE2 would result in finding the work friction did through the process. efficiency is just 100*KE2/PE1. If a mousetrap car travels along a flat surface, a starting PE of 0.5 k th^2 can be measured and maximum velocity of the car can also be measured. If energy efficiency is defined by...

Similar threads

  • · Replies 9 ·
Replies
9
Views
4K
Replies
48
Views
6K
  • · Replies 17 ·
Replies
17
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 7 ·
Replies
7
Views
5K
  • · Replies 29 ·
Replies
29
Views
5K
  • · Replies 17 ·
Replies
17
Views
10K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 15 ·
Replies
15
Views
4K