On Fri, 16 Jan 2004 02:19:30 -0500, Gary Coffman
wrote:

Work is not a time function. You can conduct air from a tank to a piston
though either a large pipe, or a restricted pipe. The resulting work done
by the piston is the same, only the rate of doing the work changes.
When doing an energy accounting (change in potential energy vs
work done), rates don't matter.

Air is driven through the aperture of a valve by a force which is the
product of the pressure differential existing across the aperture times
the area of the aperture. A small aperture will necessarily have less
force pushing air through it, and will push less air in a given time. But
that doesn't affect the amount of work the air can do on the load side.

Would you agree that downstream pressure affects the amount of work
the air can do on the load side, and that pressure drop in an
aperture depends on flow rate?