Assume you have a solid walled sphere with an opening of diameter x. The sphere has volume 0.02 litres and has air at 1.4 bars.

What general equation would be appropriate to correctly size the diameter of the sphere's opening such that pressurized air in sphere would be released in exactly 40 seconds? End pressure should be 1 bar

  • $\begingroup$ The sphere is solid... or do you mean solid wall? $\endgroup$
    – Solar Mike
    Aug 28 '19 at 22:43
  • $\begingroup$ Yes Mike. I meant a solid walled sphere. Which equation would be appropriate? $\endgroup$ Aug 28 '19 at 22:46
  • $\begingroup$ What have you considered so far? And that must be gauge pressure then. $\endgroup$
    – Solar Mike
    Aug 28 '19 at 22:48
  • $\begingroup$ Ambient pressure, velocity of air from the sphere. And volumetric flow rate. $\endgroup$ Aug 28 '19 at 22:57
  • $\begingroup$ "Gauge pressure" = pressure above ambient. "Absolute pressure" = pressure above vacuum. $\endgroup$
    – TimWescott
    Aug 28 '19 at 23:08

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