DEVELOPMENT, DESIGN, FABRICATION, AND DEMONSTRATION OF PACKAGEABLE HIGH- EXPANSION-RATIO NOZZLES FOR SOLID PROPELLANT ROCKET MOTORS

The objectives of this program were the development, design, fabrication, and demonstration of packageable high-expansion-ratio nozzles for solid propellant rocket motors. A subscale testing program conducted at Aerojet-Generals Von Karman Center altitude facility was successful in providing information for evaluating three elastomeric materials nitrile butadiene, styrene butadiene, and butyl and two refractory metals 90ta-10W and columbium for use in exit cones. Erosion data was also gathered on these elastomeric materials. A demonstration test program was conducted using three 30KS-5000 solid propellant motors, two with an elastomeric exit cone and one with a columbium expandable exit cone. Objectives were to test deployment, determine the materials integrity under operating conditions, obtain data pertaining to specific impulse at altitude conditions, and obtain postfire heat- soak data for 30 sec. Successful motor ignition, operation, and postfire heat- soak for all three tests were conducted at simulated altitudes in excess of 100, 000 ft. Attempts to deploy the elastomeric exit cone from a folded position at altitude conditions were only partially successful. However, the principle of deployment was demonstrated during sea-level tests.