Spinning Sphere travelling along axis of rotation in fluid

Click For Summary

Discussion Overview

The discussion centers on the effects of rotation on a sphere moving through a fluid, specifically when the sphere travels along its axis of rotation. Participants explore concepts related to stability, velocity, momentum, and fluid dynamics in both liquids and gases.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants propose that the rotation of a sphere may stabilize its motion, drawing parallels to the effects seen in sports balls and rifled bullets.
  • Others question whether rotation affects the sphere's velocity or momentum, suggesting that it might not unless the spinning reduces friction with the fluid.
  • There is speculation about whether the spinning could lead to a decrease in friction or if the object gains energy from the fluid dynamics involved.
  • Some participants reference experimental observations where spinning objects travel farther and faster than non-spinning ones, prompting inquiries into the underlying fluid dynamics.

Areas of Agreement / Disagreement

Participants express a range of views on the effects of rotation, with no consensus on whether it significantly impacts velocity or momentum. The discussion remains unresolved regarding the specific mechanisms at play.

Contextual Notes

Limitations include assumptions about the nature of the fluid, the conditions of the experiments referenced, and the definitions of stability and friction in this context.

traveller444
Messages
3
Reaction score
0
What effect does rotation have on a sphere moving through a fluid (liguid or gas) when traveling along the axis of rotation? The simplest being an up or down motion.
 
Physics news on Phys.org
Isn't this similar to what happens when you throw a football or baseball or other round(ish) object? And possibly why a bullet is made to spin when its fired. Would this cause the sphrere to be more stable in its motions? I don't know, I'm wondering myself now.
 
Yes, exactly. Like rifling for a bullet or a stabilizing spin for a football. However, I'm wondering more about whether it would affect velocity or general momentum.
 
traveller444 said:
Yes, exactly. Like rifling for a bullet or a stabilizing spin for a football. However, I'm wondering more about whether it would affect velocity or general momentum.

I don't know, but I would guess that it would not unless the spinning somehow caused there to be less friction on the object.
 
Drakkith said:
I don't know, but I would guess that it would not unless the spinning somehow caused there to be less friction on the object.

That's just it! Does the spinning cause the fluid to move in a way that DOES decrease the friction? Or does the object somehow acquire more energy from...somewhere?

There are some instances of experiments where an object with spin(travelling along its axis of spin) travels farther and faster than one without...so I am wondering, is that due to some sort of fluid dynamics?
 

Similar threads

Graduate Proper Multi-Axis Rotational Analysis Method
  • · Replies 7 ·
Replies
7
Views
2K
Undergrad Static sphere with gravitating fluid
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Order of rotations: precession, nutation, spin
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Steering a Car: Investigating the Forces of Rotation
  • · Replies 3 ·
Replies
3
Views
3K
Undergrad Finding the Axis of Rotation with Given CoG and Force Point
  • · Replies 32 ·
2
Replies
32
Views
3K
Undergrad Confused about the axis of rotation in rotational motion w/o slipping
  • · Replies 10 ·
Replies
10
Views
4K
Undergrad Rotating plate thrown parallel to ground
  • · Replies 2 ·
Replies
2
Views
1K
Undergrad Conservation of Angular Momentum vs a gyro at the North Pole
  • · Replies 16 ·
Replies
16
Views
1K
Undergrad Force applied on sphere by turbulent flow
  • · Replies 28 ·
Replies
28
Views
3K
Undergrad Why is there no torque along this axis?
  • · Replies 2 ·
Replies
2
Views
1K