N121-014 TITLE: Low-Erosion and Affordable Nozzles for Advanced Air-to-Air Missiles

TECHNOLOGY AREAS: Weapons

ACQUISITION PROGRAM: PMA 259

RESTRICTION ON PERFORMANCE BY FOREIGN CITIZENS (i.e., those holding non-U.S. Passports): This topic is "ITAR Restricted". The information and materials provided pursuant to or resulting from this topic are restricted under the International Traffic in Arms Regulations (ITAR), 22 CFR Parts 120 - 130, which control the export of defense-related material and services, including the export of sensitive technical data. Foreign Citizens may perform work under an award resulting from this topic only if they hold the "Permanent Resident Card", or are designated as "Protected Individuals" as defined by 8 U.S.C. 1324b(a)(3). If a proposal for this topic contains participation by a foreign citizen who is not in one of the above two categories, the proposal will be rejected.

OBJECTIVE: Develop and demonstrate low-erosion nozzle technologies that yield an affordable, thermally and structurally robust nozzle in a multi-pulse tactical solid rocket motor environment.

DESCRIPTION: Current tactical air-launched solid rockets employ reduced-smoke propellants with gas temperatures of approximately 5,000 degrees Fahrenheit and a relatively high percentage of oxidative species. Additionally, air-launched rocket motors employ fairly low-cost nozzles, which utilize phenolic inlet and exit cone materials for ablative control and thermal protection, as well as graphite throat materials for Mach 1 flow orifice erosion control. This combination of materials has proven to be suitable and cost effective for current generations of single-pulse air-to-air rocket motors. However, it is anticipated that implementing existing nozzle technologies in multi-pulse motors will cause nozzle survivability to decrease and heat soak to adjacent structures to increase because multi-pulse rocket motors have a higher total impulse and are exposed to longer operating times than single-pulse motors.

This topic is soliciting proposals for innovative nozzle technologies and architectures that can sustain exposure to hot gas with temperatures of as high as 5,000 degrees Fahrenheit for up to 10 seconds of total exposure that is supplied either continuously or split into two pulses distributed over a 30-second operating time. Target attributes are 1) nozzle throat erosions of <5 mil/s (threshold)/<3 mil/s (objective), 2) zero erosion after two full pulse operations and an inter-pulse delay, and 3) nozzle outer envelope temperatures of <200 degrees Fahrenheit at the end of a 30 second two-pulse operating sequence. Thermal shock robustness is also required, meaning that nozzle components should not crack upon cool-down after the first pulse or upon thermal shock at initiation of the second pulse.

Technologies of interest include advanced oxidative and erosion-resistant high-temperature materials, advanced structural insulator materials, advanced nozzle blast tube/inlet/entrance/throat/exit cone architectures, integral assembly technologies, and other technologies that might meet the goals identified above.

PHASE I: Design and develop material and architecture metrics. Demonstrate feasibility that candidate technologies can support the high-temperature, oxidative, long-duration, multi-thermal shock environment and meet thermal insulation goals. Perform supporting analysis anchored on feasibility demonstration and a credible material property basis to verify that candidate technology can meet project goals.

PHASE II: Develop/tailor analytical models to predict proposed technology performance and compliance to project goals. Develop component-level design and demonstrate proposed technology in the following representative environments: high temperature, oxidative gas, long-duration exposure, and multiple thermal shock events.

PHASE III: Transition technologies demonstrated under this effort to an advanced air-to-air missile propulsion system.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Materials and propulsion industry entities will benefit through advanced material and material engineering technologies that pertain to a number of high-temperature and high-speed aerospace applications. These applications include multiple next-generation air-launched propulsion systems and leading-edge hypersonic and nose tip components.

REFERENCES:
1. MIL-STD-855C. (4 May 1984). Missiles, guided, design and construction, general specification for.

2. Opeka, M. (2004). Thermodynamics based material selection for corrosion resistant performance in high temperature missile propulsion systems. Proceedings Electrochemical Society Conference on Ultra-High Temperature Materials.

3. Sutton, G. P., & Biblarz, O. (2001). Rocket propulsion elements (7th ed). New York: John Wiley & Sons, Inc.

KEYWORDS: Nozzle Materials, Low-Erosion Nozzles, High-Temperature Materials, Structural Insulators, Multi-Pulse Rocket Motors, Air-Launched Missiles

** TOPIC AUTHOR (TPOC) **

DoD Notice:   Between November 9 and December 11, 2011, you may talk directly with the Topic Authors to ask technical questions about the topics. Their contact information is listed above. For reasons of competitive fairness, direct communication between proposers and topic authors is not allowed starting December 12, 2011, when DoD begins accepting proposals for this solicitation.

However, proposers may still submit written questions about solicitation topics through the DoD's SBIR/STTR Interactive Topic Information System (SITIS), in which the questioner and respondent remain anonymous and all questions and answers are posted electronically for general viewing until the solicitation closes. All proposers are advised to monitor SITIS (12.1 Q&A) during the solicitation period for questions and answers, and other significant information, relevant to the SBIR 12.1 topic under which they are proposing.

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