Viscous thread falling on a moving belt

A stream of very viscous syrup falls from a nozzle onto a moving belt. Initially, the belt is moving so fast that the thread is just pulled out straight. As the speed of the belt is reduced, the thread first bifurcates to a meandering state, and then to a "figure eight" state. Finally, the thread falls into a coiling motion similar to what it would do on a non-moving surface.

The syrup is Newtonian.

See http://www.physics.utoronto.ca/nonlinear/papers_thread.html

Category:

Science & Technology

Tags:

• physics
• fluid
• mechanics
• rope
• coiling
• honey
• viscous
• meandering
• pattern
• formation
• bifurcation
• jackson
• pollock
• drops
• jets
• sheets
• painting

[greese007]

Right at the 1:00 mark, it did appear to make a few random loops before resuming periodic coils- perhaps not enough to qualify as a chaotic regime.

Have experiments been performed with non-Newtonian fluids, e.g. shear-thinning or shear-thickening? Would it alter the fundamental behavior?

[smorris123]

@greese007 In this movie, the parameters are changed fast, so there are a lot of transient effects.

To my knowledge, it has not been done carefully with a non-newtonian fluid. This would make a difference.

[greese007]

@smorris123 : My inquiry was prompted by correspondence with a friend in the physics dep't at Kansas U, who wondered if the same effects would occur with a limp, non-extensible string. Your Phys Rev paper suggests that they would, but I wondered if other "fluids" had been tested. Thanks for your response.

[smorris123]

@greese007 The elastic thread version of the experiment has just been published: Phys. Rev. E 84, 016219 (2011) .

[greese007]

Nice demo of transitions from periodic to chaotic behaviors. After the phase where it looked chaotic, it appeared to transition back to periodic loops, just before the video stopped. That surprised me.

[smorris123]

@greese007 Actually, none of these states are chaotic. They are all periodic in various forms. Chaotic states do form in other regimes, however.

[FlameReaper]

actualy really calming to just sit and watch that, and interesting to see how the fluid acts at the same time.

[MRtatersryummy]

Can someone explain why this happens?

[RandomNES]

how did i get here from Skyrim vids?

[ramirozabala5]

Looks delicious!

[Tongiah]

I'm actually fapping at this.

[JediKenobix]

@greese007

Transitioning from chaotic back to periodic actually happens in a lot of systems, see period doubling bifurcation and feigenbaum constant. Basically in some systems as you ramp up your paramedic your period doubles and doubles and doubles until it breaks into a chaotic regime, then comes back to a periodic regime, then starts doubling...then chaos again, etc.

[C9H9NO3]

I have the weirdest boner

[Vinifera7]

It's beautiful!

[Upwinger2020]

as a Chemical Engineer I was already guffawing and saying "Of course this is non newtonian behaviour, clearly there is an explanation with the box and spring model". then I read the description. Very surprising, I'm very interested in the papers.

[rymixxx]

I liked the bit where they dropped the goo onto the conveyor.

[nelrish24]

cool