Measurements are made of compressible flow in a long
smooth 7.16 mm i.d. tube. Air is drawn from the surroundings
(20C and 101 kPa) by a vacuum pump downstream. Pressure
readings along the tube become steady when the downstream
pressure is reduced to 626 mm Hg (vacuum) or below. For
these conditions, determine (a) the maximum mass flow rate
possible through the tube, (b) the stagnation pressure of the air
leaving the tube, and (c) the entropy change of the air in the
tube. Show static and stagnation state points and the process
path on a Ts diagram.
