Estimating Pressure Loss in Closed Tank: Hole Size vs. Time

[sarathane]

I am trying to figure out how to equate hole size to pressure loss/time for a closed tank. Here's the scenario:

300 L closed tank
Pressurized to 20 psig with air
Pressure loss is 1 psi over a time period of 1 hour
Temperature is 30 deg. C

How can I relate hole size to this pressure loss? Can assume ideal gas...just need a rough estimate/ball park answer.

 

[siddharth]

Use the conservation of mass (ie, continuity equation), the equation of state and an energy balance (ie, bernoulli equation)

 

[russ_watters]

Right - and whatever you get from that, double it, since the nozzle efficiency is probably only 50%.

 

[FredGarvin]

Not to mention it will be sonic coming out of any hole that will allow a back pressure that large.