1
$\begingroup$

Turbulence is a challenge to model and simulate:

"When I meet God, I am going to ask him two questions: Why relativity? And why turbulence? I really believe he will have an answer for the first." -- Heisenberg, Werner (1901-1976)

An analytical method often used to investigate concepts is to find the most minimal possible example of the thing you are trying to understand, so my question is: what is the theoretical or empirically observed minimum required amount of fluid for turbulence to occur?

$\endgroup$
  • 1
    $\begingroup$ i would guess that it is something like an emergent phenomena. it might not make much sense to ask exactly how many molecules etc you need for it to occur. it is rather like saying, how many grains make a pile of sand? impossible to say, but piles of sand still exist. $\endgroup$ – innisfree Apr 4 '14 at 11:06
  • $\begingroup$ Indeed, but surely we can discuss what crucial factors related to volume - could at least inhibit the emergence of phenomena such as turbulence? I am more interested in these relationships actually rather than exact numbers $\endgroup$ – hello_there_andy Apr 4 '14 at 11:10
  • 1
    $\begingroup$ Not sure what you mean by "fluid volume." For a start, volume is not a dimensionless quantity and whether turbulence could occur within a volume of fluid is not a function of the physical volume of fluid but dimensionless quantities such as the Reynolds number. The Kolmogorov scale represents the smallest scale in a turbulent flow, which depends on the viscosity and what is driving the flow. $\endgroup$ – SimpleLikeAnEgg Apr 9 '14 at 21:36
  • $\begingroup$ edited, cheers! $\endgroup$ – hello_there_andy Apr 10 '14 at 7:26
1
$\begingroup$

I recommend Turbulence: The Legacy of A. N. Kolmogorov by Uriel Frisch. It explains how turbulence is a top-down behavior, large scale turbulence in turn causes turbulence at smaller and smaller scales. This continues until a small enough scale is reached where the energy from the turbulence serves to create more heat on the molecular level. Because of this I would expect the smallest volume that can support turbulence to be a function of the viscosity of the fluid in question.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.