Strange Magnus Force in a Whirlpool

Click For Summary

Discussion Overview

The discussion revolves around the behavior of whirlpools and tornadoes in relation to the Magnus force, particularly focusing on whether this force influences their movement and stability under certain conditions. The scope includes theoretical considerations and analogies to fluid dynamics.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants suggest that the Magnus force should cause a whirlpool to move laterally depending on its spin, but question why it remains stationary.
  • One participant argues that the Magnus force applies only when there is acceleration in the water flow, not just a constant velocity.
  • Another participant contends that a whirlpool must be a solid object for the Magnus force to be applicable, which it is not.
  • There is a suggestion that the formation of a whirlpool may be influenced by the underlying ground features, which do not move.
  • A participant raises a hypothetical about whether a tornado would experience a Magnus force if strong wind currents flow towards it.
  • One response states that a wind blowing over water would not result in a Magnus force.

Areas of Agreement / Disagreement

Participants express differing views on the applicability of the Magnus force to whirlpools and tornadoes, with no consensus reached on whether it influences their behavior or movement.

Contextual Notes

The discussion highlights dependencies on specific conditions, such as the nature of the whirlpool or tornado, and the characteristics of the surrounding flow system, which remain unresolved.

Who May Find This Useful

Individuals interested in fluid dynamics, physics of vortices, and the interplay between motion and forces in natural phenomena may find this discussion relevant.

Narayanan KR
Messages
76
Reaction score
4
whrilpool.png

1. Imagine a big river with water flowing constant velocity , assume there is a whirlpool at center as shown in the figure.

2. Because of the magnus force the whirlpool should move towards left or right towards river bank depending on the spin, but it does't happens it just stays fine in its position...so why?

3. I believe that magnus force will exists in whirl pool only when the velocity of water changes (acceleration), not just velocity , since the whirlpool is itself a part of the water flow.

4. apply the same to tornado and faraday's law of electromagnetic induction (as anology).
 
Last edited:
  • Like
Likes   Reactions: makemoneyu
Physics news on Phys.org
Your whirlpool would have to be a solid object to apply the Magnus force. It is not.
In addition, the whirlpool is probably formed by some feature of the ground, and this feature does not move.
 
  • Like
Likes   Reactions: makemoneyu
its a thought experiment, question is will the conical structure of wirpool bend towards right or left when the water current changes ?
 
What happens to your whirlpool depends on the cause of it, and tons of details of the flow system.
The left side has a slower flow which will influence the flow pattern, but the details depend on the details of the system.
 
  • Like
Likes   Reactions: Narayanan KR
ok forget the whirlpool imagine a tornado, suppose a strong wind current flows towards it will it experience a magnus force?
 
A wind blowing over water? No.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 21 ·
Replies
21
Views
9K
  • · Replies 48 ·
2
Replies
48
Views
11K
  • · Replies 1 ·
Replies
1
Views
4K