Velocity and Volume of Air

Did you not ask this question yesterday?

hole_into_space

Didn't like the answers?

Please explain your question...

pressure? Maybe equal pressures on both sides of the hole... = no movement of air... maybe 10,000psi on one side and atmosphere on the other = quickly moving air...

please specify

space=atmosphere?

or do you mean outerspace=no atmosphere

*-5 mins later* ----->

ok, after reading yesterdays post, you must mean something like a pipe reaching into space(no atmosphere)... to which i will not comment.

I was thinking to logicly, about a real world situation. (way off in this situation)

You don´t read our replies. We wont read your book.

I'm assuming, differently from your original post comments, that what you have is a large chamber with stabilized pressure inside, in the value of 14.69 psia, or 1 standard atmosphere at sea level. This chamber is at space, and a 5 dia. hole is opened in the wall. What's the air flow passing by?

Hard to tell exactly. Because it would depend on the hole geometry, if there's something around, if the pressure inside the chamber drops, etc. If all the conditions are kept constant, the hole is circular, I could approach the air flow through the calculation of airflow using calibrated orifices approach.

With the mentioned delta-P (14.69psi) in a large pipe with 5 in dia. hole concentric to that pipe, within the orifice measurement pipe to orifice ratio limit, it would result in an airflow around 352 ppm, what is quite low because air density is low (exhaust pressure nominally 0 absolute). However, in volumetric flow, considering dry air at 75 degF, it would give you around 4700 cubic feet per minute.

Is it what you'd like to know?

Keep in mind that as the pressure inside the vessel drops, the air flow also drops. As time progresses, the pressure decreases, and the air flow as well.

Well, now I understand. Do you want to assume choked flow?

If so, the formula is

w = 0.53 Ap/√T

where w is lb/sec of air, A is area of hole in sq ft, p is inside pressure in psf, T is inside temperature in Rankine.

I'm thinking maybe Archer is a science fiction writer. Seems like you need to be able to answer technical questions like this to keep your writing credible.

Ed Weldon