Flow of a Compressible Fluid Through a Series of Identical Orifices

This paper contains a method for computing the weight flow of a gas or vapor through a number of like orifices. It is based upon the general equation for a single orifice and upon certain reasonable assumptions. There are included curves showing the influence of the number of orifices. For expansions beyond the over-all critical-pressure ratio, the effect of each additional orifice is increasingly reduced. For example, increasing the number of like orifices from 6 to 7 will decrease the flow only about 5 per cent. Two applications of this study are suggested, i.e., to multiple-orifice devices for heat-exchange equipment, and to labyrinth packing for shaft seals.