Maximum air velocity through a hole

AI Thread Summary
The discussion revolves around calculating the velocity of air escaping from a 6-inch diameter hole in a spaceship venting to the vacuum of space, with initial conditions of 14.7 psi and a density of 0.0023769 slug/ft^3. The user estimates the escape velocity to be about 14,115 ft/min or 160 mph and seeks confirmation or correction of this calculation. The conversation also touches on the implications of air flow dynamics in a different context, specifically regarding an air-cooled VW Bug's fan performance at high RPMs. The user is interested in understanding the limits and horsepower draw of the fan for a discussion with fellow enthusiasts. Overall, the thread combines theoretical physics with practical automotive applications.
scotty c
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this should be easy. suppose i have a very large spaceship holding a tremendous volume of air at 14.7psi with a density of .0023769 slug/ft^3. i put a hole in the side of my spaceship that is 6" in diameter which vents to the vacuum of outer space. what is the velocity of the escaping air? i did this myself and came up with a value of about 14115 ft/min or 160 mph. can anyone confirm? if i am wrong, can you point out my mistake?
 
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scotty c said:
this should be easy. suppose i have a very large spaceship holding a tremendous volume of air at 14.7psi with a density of .0023769 slug/ft^3. i put a hole in the side of my spaceship that is 6" in diameter which vents to the vacuum of outer space. what is the velocity of the escaping air? i did this myself and came up with a value of about 14115 ft/min or 160 mph. can anyone confirm? if i am wrong, can you point out my mistake?
Is this a schoolwork question? Or maybe you are writing a science fiction story?
 
an impulse drive after complete engine failure. no, just messing with you. i have an old vw bug which is of course air cooled. at some rpm point the fan in the bug will be able to draw air in so fast that the suction will exceed the ability of the atmosphere to replenish the flow. the input for the fan is about 6". I'm trying to calculate the hp draw and some limits of the fan for a discussion I'm having with some vw enthusiasts on another website called thesamba.
 
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