Air Flow Through Dual Spouts on Laid Down Jug

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Discussion Overview

The discussion revolves around the behavior of air flow and water drainage from a jug with dual spouts when laid on its side. Participants explore the dynamics of air entering the jug and the implications of adding a second spout, considering both pressure effects and flow rates.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant questions whether air would enter through the original spout or exclusively through the new top spout when both are present.
  • Another participant suggests that air pressure would be similar at both spouts, but the high speed of water exiting the jug would prevent significant air diffusion through the first spout until the jug is nearly empty.
  • A hypothetical scenario is introduced where a reservoir of water above the second spout could affect air flow dynamics, potentially restricting air from entering the first spout.
  • It is noted that having a hole at the top of the jug would maintain pressure at the bottom, allowing for smoother water flow out of the first spout, contingent on the size of the hole.

Areas of Agreement / Disagreement

Participants express varying views on the effects of dual spouts on air flow and water drainage, indicating that multiple competing perspectives remain without a clear consensus.

Contextual Notes

Participants do not fully resolve the implications of pressure dynamics and flow rates, leaving assumptions about the size of the top hole and the conditions under which air enters the jug unaddressed.

Who May Find This Useful

Individuals interested in fluid dynamics, physics of pressure systems, or practical applications of air and liquid flow may find this discussion relevant.

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If you have a five gallon jug of water with a 1/2 inch spout, and it is laid on its side, because there is no other opening in the jug it empties as air spills into the spout and replaces the water, but if the jug would have another 1/2 inch spout on it, now on top of the laid down jug,
Would any of the air still enter through the first spout or would 100% of it now come from the other spout, although probably a simple answer, I'm unsure because I've never took a physics class, but I would assume that 100% would now come from the other opening.
 
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The air outside the jug would be pressing on both spouts,
about the same pressure. But the water would (when deep)
would be going so fast out the exit hole (over 1 m/s)
that "essentially none" of the air would diffuse upstream,
until the jug was almost empty.

try it, with food coloring in the exit stream -
especially right next to the wall of the spout. Air isn't much faster.
 
what if this changed?

If the secondary spout on top had a resevoir of water pressing down on it, would the sucking in of this water hold back the air from going into the first spout?
 
If there's a hole in the top, the pressure at the bottom of the jug (at the first spout) no longer decreases rapidly as the water leaves (since there's never a vacuum made at the top). So the water just flows smoothly out, provided the hole in the top is big enough. (Eventually, if it's air coming in the top, the speed of water flow out the spout will slow, since the water depth decreases.)
 
thanx to lightgrav

I originally posted in as 2112 because I couldn't access my account, thanks for the solutions.
 

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