Marine Propeller Resistance

  • Thread starter copria
  • Start date
16
0
Is there a noticable diffence in torque required to spin a marine propeller at a constant rpm (say 2000rpm) when under a different water column? (5m vs 35m)
 

mgb_phys

Science Advisor
Homework Helper
7,744
11
Not much, water isn't very compressible.
ussually the problem is running them near the surface, the impact from air onto the surface of the water causes cavitation.
 

russ_watters

Mentor
18,651
4,886
note, however, that cavitation is reduced with depth because of the pressure.
 
16
0
If I want to optimize the energy release from cavitation would it be better to have a shallow water column (producing larger amounts of cavitation) or a deep water column (larger force collapsing the cavitation bubble)?
or
Would both cases yield the same energy release?

assuming the propeller is at a constant speed
 
Last edited:

russ_watters

Mentor
18,651
4,886
Energy release? What energy release?
 
16
0
thermal energy release
 

russ_watters

Mentor
18,651
4,886
You mean you want to eliminate cavitation, right? Higher pressure reduces/eliminates cavitation, reducing energy/efficiency loss.
 
16
0
No, I want to create cavitation (like a cavitation water heater).

Sorry I did not specify earlier.
 

Related Threads for: Marine Propeller Resistance

  • Posted
Replies
4
Views
928
  • Posted
Replies
12
Views
2K
  • Posted
Replies
1
Views
4K
  • Posted
Replies
5
Views
1K
  • Posted
Replies
7
Views
2K

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving

Hot Threads

Top