Creating controlled cavitation underwater (bubbles)

  • Thread starter Thread starter fishflyguy
  • Start date Start date
  • Tags Tags
    Bubbles Underwater
Click For Summary
SUMMARY

The discussion centers on the feasibility of creating controlled cavitation underwater using a venturi device with specific parameters. The venturi device features a 0.7500-inch inlet diameter and a 0.0937-inch throat diameter, operating at depths of 10 to 50 feet in saltwater with temperatures ranging from 5 to 20 degrees Celsius. Calculations indicate a Reynolds number of approximately 132,000, suggesting turbulent flow. However, participants express skepticism about achieving consistent non-destructive cavitating bubbles under the given conditions, recommending alternative methods such as using an air line for bubble generation.

PREREQUISITES
  • Understanding of fluid dynamics, specifically Reynolds number calculations
  • Knowledge of venturi device design and operation
  • Familiarity with cavitation phenomena and its implications
  • Basic principles of underwater mechanics and saltwater properties
NEXT STEPS
  • Research the design and optimization of venturi devices for cavitation
  • Learn about cavitation threshold calculations in fluid dynamics
  • Explore alternative methods for bubble generation in underwater applications
  • Investigate the effects of temperature and pressure on bubble formation in saltwater
USEFUL FOR

Engineers, marine researchers, and hobbyists interested in underwater fluid dynamics, cavitation effects, and bubble generation techniques.

fishflyguy
Messages
2
Reaction score
0
Hello all- First post.

I am curious if it is possible to create cavitation underwater with these specific criteria. I am basically using a venturi device that will be pulled underwater in saltwater. Is it possible to get the vapor pressure down low enough to boil water (make bubbles).

I have done some rudimentary calculations and I got some Reynolds number in the 132,000 range which would be quite turbulent flow.

Here are the parameters of my question:

Venturi inlet diameter is .7500 inches (cannot change this...hopefully)
Venturi throat is .0937 inches (3/32) in diameter. (this can diameter can change)
The total length of venturi device is 1" 3/8"
The Venturi will be operated at depths of 10 feet to 50 feet below the surface of salt water
The Venturi will be operated in salt water with a temperature of 5 degrees C to 20 degrees C
The Venturi device will be moving from 2-5 knots consistently underwater.
3 knots is 1.543 meters/ second
Venturi will be made of yellow brass.
Optimum bubble diameter would be between 1/8" to 1/4"

My two questions are:
1. can I make consistent bubbles underwater?
2. Specifically can I make NON-destructive cavitating bubbles with the above criteria?
 
Physics news on Phys.org
Cavitation , turbulence and simple bubble formation are really different things

With set up described I doubt whether you would get any noticeable effect at all .

To deliberately create cavitation you would need to use something like a badly designed powered propeller in a duct .

To create bubbles in a more practical manner the easiest way would be bring down an air line from the surface .

Is all this for a sea fishing application ??
 
could be i suppose
 
Thread 'A high school physics problem demonstrating relative motion'
I remembered a pretty high school problem from kinematics. But it seems it can help even undergraduates to develop their understanding of what a relative motion is. Consider a railway circle of radius ##r##. Assume that a carriage running along this circle has a speed ##v##. See the picture. A fly ##M## flies in the opposite direction and has a speed ##u,\quad |OM|=b##. Find a speed of the fly relative to the carriage. The obvious incorrect answer is ##u+v## while the correct answer is...

Similar threads

  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 35 ·
2
Replies
35
Views
4K
Replies
9
Views
4K
  • · Replies 15 ·
Replies
15
Views
6K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 5 ·
Replies
5
Views
8K
  • · Replies 32 ·
2
Replies
32
Views
7K
  • · Replies 17 ·
Replies
17
Views
7K
  • · Replies 5 ·
Replies
5
Views
12K
  • · Replies 8 ·
Replies
8
Views
3K