3 ms·
"Turbulence is the most important unsolved problem of classical physics." -- Richard P. Feynman "I am an old man now, and when I die and go to heaven there are
by at_a_remove 5y ago
"Turbulence is the most important unsolved problem of classical physics." -- Richard P. Feynman
"I am an old man now, and when I die and go to heaven there are two matters on which I hope for enlightenment. One is quantum electrodynamics, and the other is the turbulent motion of fluids." -- Miller
According to an apocryphal story, Werner Heisenberg was asked what he would ask God, given the opportunity. His reply was: "When I meet God, I am going to ask him two questions: Why relativity? And why turbulence?"
The Tesla Valve design is turbulence harnessed. When it comes to simulations of such, expect ... discrepancies.
- bernulli 5y agoIt's really not, though. It wouldn't work in laminar micro fluid applications otherwise.
- wolfram74 5y ago"laminar" and "micro" makes me think you've "solved" turbulence by stringently avoiding it at all costs.
- bernulli 5y agoI'm not solving anything and I did not bring turbulence into this. Parent wrote that the Tesla valve harnesses turbulence to function, I gave a counterexample of how Tesla valves are applied for laminar microflows, ergo turbulence cannot be the working principle behind Tesla valves.
- amelius 5y agoCan't the simulation at least give some error bars?
- at_a_remove 5y agoJust asking that, you are not familiar with the horror of turbulence. I put those quotes in for a reason: some very great minds have stared into the abyss of turbulence. The Navier-Stokes equations have a "smoothness problem" where some values sometimes go to infinity. Error bars on infinity ...
- bernulli 5y agoThis makes no sense whatsoever, maybe the abyss has stared back? Turbulent flows can be quite predictable, as the fluctuations smooth out statistically. Even simple turbulence models are quite accurate when it comes to the effect of turbulence, say, in pipe flow, or over flat plates and airfoils. Even for situations in which that is not the case, why would error bars go to infinity? As to the smoothness problem, that may get you to claim a $1,000,000 Millenium prize in mathematics, but plays no role whatsoever in practical simulations.
- bernulli 5y agoThat's a great question and indeed a full research direction -- uncertainty quantification. Unfortunately it turns out that it's not that simple.