On the flow of gases at high speeds

Abstract

In a paper on the discharge of gases under high pressures* the late Lord Rayleigh called attention to the deficiencies in the present state of knowledge of the characteristics of the flow of a gas, from a vessel in which it is compressed, through an orifice into the atmosphere or into a receiver at a lower pressure, and suggested that further study was desirable in the direction of investigating the accuracy of the common assumptions of the adiabatic character of the flow and its dependence on the pressure in the receiver. Assuming adiabatic flow the values of the velocity of the jet and the rate of discharge are given by the well-known relations- u 2 /2 = γ/γ-1. p 0/ρ0{1-( p / p 0)γ-1/γ}, w = g A√ 2γ/γ-1. p 0ρ0( p / p 0)2/γ {1-( p / p 0)γ-1/γ}, where u is the speed, p and A the pressure and area of the jet, and w the rate of discharge, the suffix 0 referring to the conditions inside the discharging vessel where u = 0.