An experimental technique for measurement of injector spray mixing

Abstract

Introduction P studies have related liquid-rocket spray characteristics to injector mechanical and hydraulic parameters and/or combustion efficiencies from hot firings, i.e., to measured performance, but none has predicted combustion efficiency from spray measurements. This Note presents a technique that combines spray data obtained with nonreactive propellant simulants with an analytical model to predict the loss in combustion efficiency due to nonuniformities in the propellant mixture ratio distribution. Efficiencies thus predicted are compared with hot-firing results. The combustion chamber is considered to be divided into a primary mixing zone that includes the initial combustion region and that terminates when the gas velocity has essentially turned the spray in the axial direction, and a secondary zone, wherein turbulent vaporization and combustion occur within stream tubes, but with no thermal or mass transfer between stream tubes. c) V FROM 1-D COMBUSTION MODEL gas _ £ = 3.0; D 200/*