Solid Propellant Thrust Control Using a Movable Nozzle

ABSTRACT: In Phase I, CFDRC examined concepts for thrust management of a SRM that moved the nozzle relative to a fixed pintle. A binary high/low thrust motor operating mode was selected and a heavy-wall test bed that used the pressure from the chamber to move the nozzle back and forth was demonstrated. A simple, inexpensive pneumatic valve provided the only actuation required. In Phase II, CFDRC proposes to design, build and test a hot-fire version of this binary-mode motor that will demonstrate sustained operation of the motor using a quasi-realistic propellant. The testing will also provide data for validation of a transient simulation tool to be developed during the program that will aid in integration of the technology for future missile systems. CFDRC has secured interest in this activity from Raytheon, ATK and MEI, and from various DoD program offices. In Phase III, this motor will be available to the Air Force, Navy and/or Army labs for additional firings using military production propellants. CFDRC plans to transition this technology to a second stage version of the Navy SM-6 missile, where CFDRC"s thrust management capability will increase the terminal phase footprint and promote increased agility. Upgraded versions of the Army NLOS-PAM and the Air Force HARM missions are also immediate Phase III opportunities. BENEFIT: The benefit of on-demand thrust modulation of an SRM in a robust, low-cost form will be applicable to a number of missile systems within multiple DoD agencies. Besides the Navy"s SM-6 upper stage, the Army has pursued this technology for most of a decade, almost incorporating it into its NLOS-PAM missile program. Once the approach outlined in this proposal has been validated, CFDRC will work with SRM primes such as ATK to transition this technology to the field. CFDRC will benefit commercially through license revenue and subcontracts with the system and propulsion prime contractors as this technology is adapted to fielded and future systems.