N221-051 TITLE: Enhanced Performance for Fin and Control Surface Materials for High Speed Missiles

OUSD (R&E) MODERNIZATION PRIORITY: Hypersonics

TECHNOLOGY AREA(S): Materials / Processes

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop a common missile fin and control surface architecture which provides a significant increase in thermostructural capability for multiple future missile systems.

DESCRIPTION: Evolving weapons technology is driving advanced missiles (supersonic and hypersonic) and other flight vehicles to greater speeds and higher accelerations. The result of increased speed and acceleration is higher temperatures and thermal stresses. For instance, vehicles traveling over Mach 4 may reach surface temperatures of 2,100�C at their leading edges. Rapid acceleration results in extreme thermal gradients, translating to high stresses. Flight through adverse weather such as rain or sleet, and sand and dust add additional environmental hazards which must be survived. These conditions resulting from implementation of the evolving technologies will require changes in materials to meet or exceed requirements to negate the effects on missile fins and control surfaces. Current materials do not address the problems occurring. Existing solutions are based on stainless steel or nickel-based super-alloys. Temperatures experienced in hypersonic flight will exceed the structural limits of these materials. An innovative solution will consider both advanced materials and existing state-of-the-art materials. Thermal shock is particularly difficult and can cause expansion of the outer surface during acceleration, thereby impacting fin and control surface effectiveness and material structural integrity.

Critical components of future Navy missile concepts are fixed body fins and articulating control surfaces. These fins and control surfaces must withstand significant mechanical loads, extreme surface temperatures, significant temperature gradients, and avoid conducting excessive heat back into the missile body. The fixed fins may be mounted on the rocket motor, and the articulating control surfaces are mounted via an actuator shaft which is connected to an internal actuator mechanism. Thermal limits for internal components behind fins and control surfaces may be as low as 225�C. It is desired that this future fin and control surface technology have a common design architecture which will allow use across multiple missile types and reduce production costs by eliminating multiple fin types. With these objectives in mind, the U.S. Navy seeks a fin and control surface design that utilizes proven materials and manufacturing methods, but also material innovations to provide increased thermal performance while maintaining structural functions.

Notional control surface geometries are like those found on legacy Navy interceptors, which are generally approximately 9" length and span, and no more than 1" thick at the root. Lower-weight assemblies are favored. The control surfaces should be capable of withstanding panel loads of 1,500 lbf with hinge moments of 2,000 in-lb. to the actuator. Novel constructs are envisioned that build upon current state-of-the-art with material additions, substitutions, or layering. Novel new materials, or novel combinations of known appropriate materials, may be considered. It is preferred that materials with known properties be incorporated into the proposed solution to potentially reduce the time to meet the technology readiness. Materials with smoother properties are favored. Proven manufacturability and properties will be favorably considered. Advanced and novel materials could be integrated into the basic structure and added as additional elements or layers.

Some critical considerations for any such control surface design and materials system include: (1) design optimized for both thermal and mechanical considerations; (2) high temperature chemical compatibility between multiple materials; (3) adhesion between material interfaces or layers; (4) thermal properties (conductivity, emissivity, coefficient of thermal expansion); (5) mechanical properties (strength, strain to failure); and (6) shape control in fabrication. Adequate test protocols must demonstrate suitability of the proposed technology to satisfy Navy requirements. Testing can be conducted on coupons combined with modeling, or on notional prototypes. Testing must demonstrate the proposed technology can withstand anticipated hypersonic flight conditions. While testing to MIL-STD-810 is beyond the scope of this SBIR effort, proposers may wish to consider the potential effects of all storage and flight environments on proposed materials and structures.

PHASE I: Develop a concept for a common fin and control surface architecture that meets the parameters in the Description. Demonstrate that the concept can feasibly meet the requirements through analysis, modeling, and experimentation of materials of interest. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II.

PHASE II: Develop and deliver notional full-scale prototypes that meet the requirements in the Description. Note that this effort is iterative by nature and more than one prototype (or partial prototype) may be developed. Demonstrate functionality under the required service conditions including thermal and mechanical stresses. Demonstrate the prototype performance through the required range of parameters given in the Description. Number of prototypes tested will depend on the details of test methods chosen. Additionally, deliver two untested prototypes, test data, and remnants of tested prototypes to the Navy (NSWC Carderock Div., West Bethesda, MD).

PHASE III DUAL USE APPLICATIONS: Support the Navy in transitioning the technology to Navy use in the STANDARD Missile program. Support the manufacturing of the components employing the technology developed under this topic and assist in extensive qualification testing defined by the Navy program. It is likely that the Phase III work will involve classified information. While it is not a requirement for the offeror to be capable of classified work, such capability would simplify future efforts. It may also be possible for the offeror to partner with a classified-capable manufacturing firm to accomplish this step in the future work.

Potential commercial uses for high temperature performance improvements exist in the commercial spacecraft and aircraft industries and satellite communications.

REFERENCES:

1. Kasen, Scott D. "Thermal Management at Hypersonic Leading Edges." PhD Thesis, University of Virginia, 2013. https://www2.virginia.edu/ms/research/wadley/Thesis/skasen.pdf.
2. Ognjanovic, Ognjen; Maksimovic, Stevan; Vidanovic, Nenad; Kastratovic, Gordana and Maksimovic, Katarina. "Structural Analyses Of Balistic Missile Fin Configuration During Supersonic Flight Conditions." Annals of the Faculty of Engineering Hunedoara; Hunedoara, Vol. 16, Iss. 1, Feb 2018, pp. 179-182. http://annals.fih.upt.ro/pdf-full/2018/ANNALS-2018-1-30.pdf.
3. Ognjanovic, O.; Maksimovic, S.; Vidanovic, N.; Segan, S. and Kastratovic, G. "Numerical aerodynamic-thermal-structural analyses of missile fin configuration during supersonic flight conditions". Thermal Science, 21(6 Part B), January 2017, pp. 3037-3049. https://doi.org/10.2298/TSCI160919318O http://www.doiserbia.nb.rs/img/doi/0354-9836/2017/0354-98361600318O.pdf.

KEYWORDS: Missile Fins; Control Surfaces; Advanced Missiles; Thermal Shock; Supersonic; Hypersonic