Book Description

An analytical method is presented for determining the flow characteristics of a two-phase flow of liquid drops in a gas stream as the mixture expands through an annular converging-diverging nozzle. The subject analysis can be utilized to predict the liquid velocity, gas velocity, static pressure, and droplet diameter as a function of AXIAL DISTANCE ALONG THE NOZZLE FOR A TWO-PHASE FLOW THAT CONTAINS APPROXIMATELY 10 TIMES AS MUCH LIQUID AS GAS BY WEIGHT. Two nozzle configurations were investigated. Both had the same converging angle of 20 degrees, throat radius of 1 in., inlet area of 3.287 sq. in., throat area of 0.267 sq. in. and exit area of 2.450 sq. in. One nozzle had a total diverging angle of 7 degrees and the other had a total diverging angle of 21 degrees. Flow rates of between 8 and 11 lb/sec of water and between 1.0 and 1.3 lb/sec of air were utilized. The liquid and gas were expanded from a low velocity and a pressure of 500 psig to ambient pressure. The theoretical and experimental pressure profiles matched closely for both nozzles investigated. The thrust was predicted to an accuracy of approximately 3% for the short nozzle, but to an accuracy of only approximately 20% for the long nozzle.