v22/2g = {p0τ1γ / G0τ0 (γ − 1)} {1 − (p2/p1)(γ−1)/γ};
(2)
or, inserting numerical values,
v22/2g = 183.6τ1 {1 − (p2/p1)0.29};
(2a)
which gives the velocity of discharge v2 in terms of the pressure and absolute temperature, p1, τ1, in the vessel from which the air flows, and the pressure p2 in the vessel into which it flows.
Proceeding now as for liquids, and putting ω for the area of the orifice and c for the coefficient of discharge, the volume of air discharged per second at the pressure p2 and temperature τ2 is
Q2 = cωv2 = cω √ [(2gγp1 / (γ − 1) G1) (1 − (p2/p1)(γ−1)/γ)]
= 108.7cω √ [τ1 {1 − (p2/p1)0.29}].
(3)