Mixture ratio distribution - Its impact on rocket thrust chamber performance.

Abstract

Irregular mixture ratio (Q/F) distribution across the face of an injector can result from unequal hydraulic resistances to injector elements and by chamber cooling requirements. The degree to which O/F distribution will influence specific impulse (7sp) depends upon the propellant system and operating conditions, the extent of the O/F deviations, and the degree of turbulent mixing in the combustion chamber; /sp losses up to 5% have been observed. The objective of this work is to show how these effects can be taken into account in rocket thrust chamber designs by use of a stream-tube analysis. Evaluations of three rocket thrust chamber systems utilizing either the liquid-liquid or gas-liquid injector designs are illustrated. Experimental results are shown which verify predicted performance gains due to control of the propellant distribution in the injector.