NACA Research Memorandums

Abstract

Report presenting an investigation to determine the performance characteristics of a double-shroud cooling-air ejector configuration. Two convergent nozzles were used to simulate a specific manufacturer's iris-type variable-area nozzle in the open and closed positions. The investigation had four phase: (1) obtaining performance with no secondary or tertiary air flow, (2) determining the tendency for backflow to occur in either cooling-air passage, (3) determining the sensitivity of flow in one passage to the other, and (4) obtaining pumping and thrust characteristics with secondary and tertiary air flow