Air force 17. 1 Small Business Innovation Research (sbir) Phase I proposal Submission Instructions

REFERENCES:

1. ASTM E1441-97 (Reapproved 2003), “Standard Guide for Computed Tomography (CT) Imaging” (1997), West Conshohocken, PA.

2. ASTM E1695-95 (Reapproved 2013), “Standard Test Method for Measurement of Computed Tomography (CT) System Performance” (1995), West Conshohocken, PA.

3. ASTM 1570-00 (Reapproved 2011), “Standard Practice for Computed Tomographic (CT) Examination” (2000), West Conshohocken, PA.

KEYWORDS: microfocus computed tomography, nondestructive inspection, artifacts and noise, ICBM components, cone-beam CT images

AF171-056

TITLE: Fiber Optic Sensing Systems (FOSS) for Expendable Launch Vehicles

TECHNOLOGY AREA(S): Space Platforms

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 section 5.4.c.(8) of the solicitation and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the AF SBIR/STTR Contracting Officer, Ms. Gail Nyikon, gail.nyikon@us.af.mil.

OBJECTIVE: Precision FOSS health monitoring system to augment or replace legacy instrumentation systems on expendable launch vehicles.

DESCRIPTION: The Fiber Optic Sensing System (FOSS) technology, under development at NASA, is a pervasive game-changing technology that can benefit multiple SMC programs. The FOSS concept involves sensors capable of being distributed in vast networks that yield an unparalleled amount of real time engineering data - up to 100x the number of measurements for 1/100 of sensor weight. By detecting changes in reflected wavelength from a laser source, stress, temperature, deflections, and other measurements can be made at numerous hard to reach locations, embedded into composite structures, and easily installed and calibrated. Other benefits include accuracy, reliability, and immunity to electromagnetic interference (EMI). FOSS has been demonstrated on aircraft test flights but the technology has not been bridged to space systems.

As an alternative to the legacy current/voltage health monitoring systems on EELV launch vehicles, FOSS can provide an order of magnitude more engineering information that can be used for model anchoring, design optimization (e.g., reduction in overly conservative margins leading to reduced weight), and pre/post mission analysis. Benefits also extend to faster design / development cycles, quicker flight anomaly resolution, and greater launch availability.

This solicitation seeks to develop an affordable, reliable FOSS architecture to replace strain gauges, accelerometers, thermocouples, and propellant level sensors for future EELV launch vehicles. Along with the system architecture, the deliverable will include a cost, weight, power and reliability impact assessment.

Technology Need Date: 2023 (EELV Phase III)

PHASE I: Feasibility study on what types of instrumentation and sensors on future expendable/reusable launch vehicles can benefit from FOSS, together with metrics on cost, weight, accuracy, reliability and other engineering or manufacturing benefits.

PHASE II: Subscale demonstration comparing FOSS to legacy current/voltage based health monitoring systems on a representative launch vehicle subsystem (propellant tank, composite skirt, engine nozzle, etc.)

PHASE III DUAL USE APPLICATIONS: Flight demonstration on an EELV launch vehicle validating FOSS capability and benefits. Transition plan for commercial deployment of FOSS to select industries.

REFERENCES:

1. Hon Man Chan et al., "Fiber-Optic Sensing System: Overview, Development and Deployment in Flight at NASA," NASA NTRS Technical Report AFRC-E-DAA-TN25056, 10 Dec 2015.

2. F. Pena et al., "Fiber Optic Sensing System (FOSS) Technology: A New Sensor Paradigm for Comprehensive Subsystem Model Validation throughout the Vehicle Life-Cycle," NASA Armstrong Briefing, 26 Oct 2015.

KEYWORDS: FOSS, fiber-optic, instrumentation, sensor, health monitoring, launch vehicle, transducer, measurement, space

AF171-057

TITLE: Dynamic and Efficient Vapor Compressor for Aircraft Thermal Management Systems (TMSs)

TECHNOLOGY AREA(S): Air Platform

OBJECTIVE: To develop and demonstrate an approximately 125 to 150 kW nominal capacity, dynamically responsive refrigerant vapor compressor which can sustain high efficiency over a range of turn-downs for next-generation aircraft thermal management systems (TMS).

DESCRIPTION: Aircraft have become thermally constrained such that during specific operating points, thermal requirements can exceed available sinks. This problem has been exacerbated further due to a rise in aircraft mission-related equipment. These challenges have necessitated the development of more efficient and adaptive thermal cycles which can more effectively manage thermal lifts and make better use of available aircraft heat sinks.

Several strategies for increasing TMS power density and responsiveness have been proposed including development of advanced vapor compression systems (VCS) and hybridization of VCS with conventional air cycle systems (ACS). While these approaches appear viable, highly efficient and power-dense vapor compression options, which can maintain high efficiency over a broad range of inlet and discharge pressures, are limited. The objective of this topic is to develop and test a highly dynamic vapor compressor or compressor/compressor hybrid which demonstrates high efficiency over a range of inlet and discharge pressures. Ideally, oil-less compressor strategies which permit efficient flow turn-downs of as much as 10:1 at a total capacity (mission equipment thermal loads) up to 125 to 150 kW are desired. Specific design objectives include saturated suction temperatures (SST) as low as 1.7 degrees C (35 degrees F) with 2.58 MPa (375 psia) maximum condenser pressure. Also, the compressor must be able to change its capacity (mass flow) at a rate of at least 15 percent per second.

Compressor solutions must be tolerant to 32.2 degrees C (90 degrees F) inlet temperatures. A minimum isentropic efficiency of 0.5 is desired. The primary motivation of this effort is to demonstrate an aviation-grade compressor which minimizes off-design efficiency reductions over the specified turn-down range. However, offerors are encouraged to consider power density (max cooling capacity/compressor mass) as a secondary, but still critical factor in aviation-grade hardware. As such an objective for compressor power density is 8 to 9 kW/kg. Additionally, if possible, the compressor should have no inherent materials incompatibilities with other refrigerants, such as R152a, R236fa, R245fa, etc.

It is anticipated that the compressor to be developed will be electric motor driven. If so, the motor and motor controller design should be considered. Additionally, a model, or compressor maps and dynamic performance data, would be desirable to enable evaluation of the suitability of the compressor for operability within TMS architectures under consideration. While not required, it may be beneficial for the offeror to develop a relationship with a weapons system contractor or subsystem supplier to facilitate transition of successful compressor technology to future architecture demonstrations, and ultimately to future aircraft TMS.

At the conclusion of this activity, AFRL would seek to demonstrate successful compressor concepts as part of ongoing adaptive, next-generation aircraft power and thermal management system technology efforts. As such, delivered hardware may be operated in AFRL’s Vapor Compression System Research Facility (VCSRF) laboratory to verify performance against program desirements.

PHASE I: Design and demonstrate a vapor compressor or hybrid compression configuration which meets the above specifications. A predicted compressor map of the proposed system should be provided to the Government at the conclusion of this effort. Further, the offeror shall demonstrate that they have the necessary facilities and expertise to manufacture a prototype system under Phase II funding.

PHASE II: Refine the design and produce a prototype version of the compressor concept developed under the Phase I. To accommodate Phase II test constraints, a subscale prototype of approximately 75 to 100 kW may be acceptable, though this subscale prototype must still meet desired design requirements. At the conclusion of this effort, the offeror must demonstrate operation of the device through either internal characterization, in conjunction with AFRL’s vapor compression test bed, or both.

PHASE III DUAL USE APPLICATIONS: Commercial applications include aviation-grade cabin-air coolers and related cooling applications. Military applications include advanced thermal management systems for aircraft.

REFERENCES:

1.  Ensign, T.R. and Gallman, J.W., "Energy Optimized Equipment System for General Aviation Jets," Proceedings of the 44th AIAA Aerospace Sciences Meeting and Exhibit, January, 2006 (228) doi:10.2514/6.2006-228.

2.  Walters, E.A. and Iden, S., "Invent Modeling, Simulation, Analysis and Optimization," Proceedings of the 48th AIAA Aerospaces Sciences Meeting, January 2010 (287) doi:10.2514/6.2010-287.

3.  Michalak, T., Emo, S., and Ervin, J., "Control strategy for aircraft vapor compression system operation," Int. J. Refrigeration, Elsevier, Vol 48, December 2014, pp 10-18, doi:10.1016/j.ijrefrig.2014.08.010.

4.  Dexter, P., Watts, R., and Haskin, W., "Vapor Cycle Compressors for Aerospace Vehicle Thermal Management," SAE Technical Paper 901960, 1990, doi:10.4271/901960.

5.  Delash, T., "Vapor Cycle Compressor Range Expansion for Aerospace,” SAE Technical Paper 2011-01-2586, 2011, doi:10.4271/2011-01-2586.

KEYWORDS: aircraft thermal management, aircraft environmental control systems (ECS), vapor compression system (VCS), aircraft cooling

TECHNOLOGY AREA(S): Air Platform

OBJECTIVE: Develop a non-persistent nano-scale tracer injection system for particle image velocimetry in high-speed wind tunnels. Particles must have a known finite lifetime, survive and track flow in hypersonic wind tunnels, and accept fluorescent coatings.

DESCRIPTION: The non-intrusive measurement of fluid velocity in wind tunnels depends heavily upon particle-based diagnostics. Particle image velocimetry (PIV) allows for both two- and three-dimensional measurements of the instantaneous velocity field, in which the fluid velocity is approximated by the motion of injected tracer particles [1]. In order to minimize the measurement error associated with particle lag, measurements in supersonic and hypersonic flows typically require a particle diameter d_p between 100 and 200 nm. Additional desired performance characteristics may include low material density (to minimize buoyancy effects), high reflectivity or index of refraction (to maximize scattered laser signal), and the ability to accept fluorescent coatings (to mitigate wall reflections) [2].

Particle injection, whether using liquid aerosols or solid tracers, is typically tolerated in blowdown wind tunnels due to the minimal impact upon facility infrastructure, though increased fouling of vacuum pumps and windows may be experienced. For closed-circuit facilities, the persistent nature of the tracers leads to increased build-up along compressor fans and turning vanes, thus requiring expensive and time-intensive cleaning (if such cleaning is even possible). The development of non-persistent tracers is seen as a possible solution, as the particles would evaporate/sublimate downstream of the measurement location. Early efforts at clean seeding have used dry ice crystals [3], though nominal particle diameters are still too large for regular usage, and the particles are not suitable for injection into the high-temperature settling chambers of hypersonic wind tunnels.

The goal of this effort is to develop a non-persistent PIV seeding system for supersonic and hypersonic wind tunnels. The tracer particles will have a nominal diameter d_p between 100 and 200 nm (as measured in the test region of the flow). Particle lifetime will be short enough to prevent accumulation in wind tunnel infrastructure, and will be sufficiently long to allow particles to convect from the injection location through the test section. Seeding material shall pose no major toxicity danger to personnel, and will not corrode mechanical equipment. Methods and procedures should be provided for applying fluorescent coatings to the non-persistent tracers.

In order to successfully perform the work described in this topic area, offerors may request to utilize unique facilities/equipment in the possession of the U.S. Government located at Arnold Air Force Base during the Phase II effort, including VKF Tunnel D.

PHASE I: Demonstrate the seeding injection system on a bench-top level, showing the nominal particle diameter d_p < 200 nm. Measurements shall include median particle diameter, along with size distribution. Tracer lifetimes will be appropriate for usage in VKF Tunnel D at Arnold Engineering Development Center (AEDC). The ability of particles to reflect laser light (i.e., for PIV) shall be demonstrated.

PHASE II: Install seeding injection system into VKF Tunnels A or D, for use with government-furnished PIV system. Effectiveness of particles will be demonstrated for various test geometries, including flat plates and wedges. Particle response times will be measured in situ. Particle reflectivity will be compared to traditional persistent tracers (either solid or liquid).

PHASE III DUAL USE APPLICATIONS: Seeding injection system will be further refined for high-temperature applications comparable to those in VKF Tunnel C. Particle survival in high-temperature environments will be demonstrated. Supplementary demonstrations may include particle scattering with and without fluorescent coatings. Possible commercialization applications include customized seeding systems for large-scale and/or closed-loop wind tunnel facilities.

REFERENCES:

1. Ragni, D., Schrijer, F., van Oudheusden, B., and Scarano, F., "Particle Tracer Response across Shocks Measured by PIV," Experiments in Fluids 50(1), pp. 53-64 (2011).

2. Petrosky, B., Lowe, K., Danehy, P., Wohl, C., and Tiemsin, P., “Improvements in Laser Flare Removal for Particle Image Velocimetry using Fluorescent Dye-Doped Particles,” Measurement Science and Technology 26(11) (2015).

3. Liber, M.L., Reeder, M., Wolfe, D., Schmit, R., and Hagen, B., “PIV in the Trisonic Gas Dynamics Facility,” AIAA Paper 2014-2661.

KEYWORDS: supersonic, hypersonic, flow diagnostics, particle image velocimetry, particulate, materials, seeding

AF171-059

TITLE: Sustainable High-temperature Hybrid Turbine Rotors

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 section 5.4.c.(8) of the solicitation and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the AF SBIR/STTR Contracting Officer, Ms. Gail Nyikon, gail.nyikon@us.af.mil.

OBJECTIVE: Develop a durable and sustainable joining method for high-temperature hybrid turbine components.

DESCRIPTION: Increasing engine temperatures are expected to present significant thermomechanical challenges for conventionally manufactured turbine disks. This is because the conventional disk alloy, with its fine grain structure, is designed mainly to withstand burst, but is only intended to operate at relatively low secondary flowpath temperatures. Turbine blades, which generally run at the much higher primary flowpath temperatures, are now being made of single-crystal alloys, for improved creep resistance. However, in advanced engines, where the disk rim temperatures are coming uncomfortably close to those of the primary flowpath, the disk alloy in this region could undergo adverse grain growth and creep, which when coupled with the high centrifugal forces at the rim, can result in a catastrophic turbine disk failure.

There are a number of ongoing efforts to develop a hybrid disk that will meet both requirements (to be rupture-proof at the bore and creep-resistant at the rim). Currently available joining methods include:

The goal is to develop a method for producing a durable high-temperature hybrid turbine disk. The key performance parameters include the ability to produce a clean bond line (no voids, cracks, or local deformations or phase changes), while maintaining the parent materials properties. Anticipated military engine systems benefits include higher OPR driving temperature capabilities to handle high T4 and T3 (longer life with lower cooling) and reduced cooling flows. Anticipated benefits to the warfighter include lower maintenance costs and increased system availability.

PHASE I: Determine the feasibility of producing a durable high-temperature dual-alloy disk. Develop a structural integrity and durability evaluation plan, including both destructive and nondestructive test methods.

PHASE II: Produce two test disks. Use the structural evaluation plan developed in Phase I to assess the structural integrity and mechanical properties of the test disks. Make recommendations for scaling up the process to produce advanced turbine rotors.

PHASE III DUAL USE APPLICATIONS: Potential commercial applications for this technology include military and civil air-, sea-, and land-based propulsion and power generation systems.

REFERENCES:

1. http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110020259.pdf.

2. http://www.au.af.mil/au/awc/awcgate/vistas/match8.pdf.

3. http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000732.pdf.

4.  http://www.omicsgroup.org/journals/review-and-analysis-of-powder-prior-boundary-ppb-formation-in-powder-metallurgy-processes-for-nickelbased-super-alloys-2168-9806-1000127.php?aid=49144.

5. http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120001798.pdf.

KEYWORDS: turbine disk, hybrid disk, dual-alloy disk, turbine rotor, turbine engine, diffusion bonding, linear friction welding, joining techniques, dual-property disk

TECHNOLOGY AREA(S): Air Platform

OBJECTIVE: Develop a smaller sized aerial refueling boom concept that serves the needs of tactical aircraft, is more easily integrated onto a tanker in a variety of locations, and features novel actuation and control capabilities for robust operation.

DESCRIPTION: Today’s aerial refueling booms are designed to transfer fuel at high rates, and are sized to meet the needs of legacy bomber aircraft and heavy transports. Current and legacy fighters can accept fuel transferred only at an appreciably slower rate, and as such, the current refueling booms are oversized. Tanker aircraft do periodically refuel bomber and mobility aircraft, but the majority of refueling sorties are for fighter aircraft. In looking to the future, as unmanned combat air vehicles (UCAVs) enter the inventory, the demand for refueling of smaller, tactical vehicles will increase. A better match would be a new, smaller boom, appropriately sized for offloading fuel to fighters and UCAVs; it would be easier to integrate onto tankers in a variety of locations (wing mounted, off centerline, on the ramp, etc.), require less powerful actuators to enable the full range of control, and impart lower reactive loads onto the tanker. As the Air Force considers smaller tanker aircraft to meet emerging needs in future environments, there is a unique opportunity to develop a right-sized smaller boom for servicing tactical receivers.

An additional desire is the ability to service both receptacle-equipped receiver aircraft (typical for Air Force aircraft) and probe-equipped aircraft (typical for Naval, rotary wing, coalition aircraft) on the same flight. This is currently done with a centerline-mounted boom and wing-mounted hose and drogue pods; this is standard on existing tankers. There would be great utility in having a multi-mode device that could service both types of receivers on the same sortie.

To aid in integration into the tanker, novel control effectors and mechanisms are sought. Current booms have small wings, which provide aerodynamic forces to steer the boom into different relative positions as the boom operator attempts to connect with the receiver aircraft. These wings are effective, but quite bulky; they create appreciable drag when not in use, and prevent the boom from being stored internally in the tanker. Unconventional control effectors could be examined to understand the strengths and weaknesses in this sort of application. Possible solutions could include, but are not limited to, flow control (pneumatic, mechanical, electrical or otherwise), shape memory alloys, morphing or flexible structures, etc. An additional consideration is the ability of the boom effectors to be effective at generating the required loads across a larger flight envelope, as the Air Force seeks to broaden the range of flight conditions (especially higher altitudes and lower speeds) at which it can conduct aerial refueling. The boom should retain adequate control-margin in aircraft-wakes and in challenging flight conditions. Another useful capability would be to develop a refueling device which is small enough to be mounted to the aircraft externally, and to open up the possibility of buddy refueling or every-aircraft-a-tanker operational concepts.