6 comments

  • barrenko2 days ago
    &gt; in case someone wants to get nerdsniped <a href="https:&#x2F;&#x2F;github.com&#x2F;kamilazdybal&#x2F;fluid-toolbox" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;kamilazdybal&#x2F;fluid-toolbox</a>
    • glouwbug32 minutes ago
      Gases work roughly the same way (until they break the ideal gas law and don&#x27;t). The ratio of static and dynamic pressures between two chambers can drive nozzle flow [1]. Add in some compression and combustion and you can simulate anything from refrigerators to engines.<p>[1] <a href="https:&#x2F;&#x2F;github.com&#x2F;glouw&#x2F;ensim4&#x2F;blob&#x2F;master&#x2F;src&#x2F;chamber_s.h#L125" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;glouw&#x2F;ensim4&#x2F;blob&#x2F;master&#x2F;src&#x2F;chamber_s.h#...</a>
  • NewsaHackO2 days ago
    &gt; As everyone learns in kindergarten, the speed at which water comes out of a spout in a tank depends on the height<p>What kindergarten did you go to? Maybe my public kindergarten education was seriously lacking.
    • tbt1 day ago
      Oh sorry that was a joke. (Though you <i>could</i> teach that in kindergarten.) When I was in undergrad I had the privilege of taking Laszlo Babai&#x27;s combinatorics class. I don&#x27;t recall exactly how he phrased it, but he would say things like &quot;As everyone learns in kindergarten, the powerset of [n] has size 2^n.&quot;.
      • NewsaHackO1 day ago
        Oh my bad, good article though.
  • gpm2 days ago
    &gt; Ok, so, it’s the same as before, but the outlet of the spout is now significantly deeper &#x2F; lower. So the speed of the water should be higher, right?<p>&gt; Ok, but if the water is faster at the bottom of the long spout… We could view the top part of this system as an exact copy of the short-spout version. At the interface between the tank bottom and the pipe-spout, the velocity of the water should be the same as in the no-pipe version, right? But that means the water inside the pipe is accelerating inside the pipe:<p>No, it&#x27;s not the exact same. In the top part of the long-spout system there&#x27;s a lack of airpressure holding the water above it back compared to the short-spout, and quite a bit of cohesion in the water pulling the water above it down faster if the lack of air pressure isn&#x27;t enough. The water in the whole system moves faster as a result.<p>You&#x27;d theoretically get the air (actually vacuum) bubble if you ran the experiment in a vacuum with a liquid that has no cohesion... liquids with no cohesion are otherwise known as gasses though and behave differently in other ways as well.
    • tbt1 day ago
      Ohhh, oops, good point, thanks.
  • MarkusQ2 days ago
    Really nice to see the process of thinking it through. This sort of thing gives a much better insight than just memorizing formulas.
  • BobbyTables21 hour ago
    Love the thinking but was booing there would be some enlightenment at the end…
  • alienbaby2 days ago
    Unfortunately nobody in the UK can see the images in the blog, &#x27;cause imgur
    • tbt1 day ago
      Sigh, thanks for letting me know. Ok since this is the ~third time someone has said this, I&#x27;ll try to figure out a convenient solution (I guess hosting images on github?). Just FYI a VPN should let you see imgur images.