Air force 16. 1 Small Business Innovation Research (sbir) Proposal Submission Instructions

PHASE II: Develop a fully functional high temperature printed circuit board assembly with high-temperature semiconductors, passive components and related materials. Select a relevant aircraft or engine component such as the FADEC, inverter/converter control, or fuel control system. Demonstrate the technology in a relevant engine/aircraft rig under suitable environmental conditions. Refine transition plan/business case analysis.

PHASE III DUAL USE APPLICATIONS: Fabricate ground engine test electronic hardware for demonstration in relevant turbine engines or other aerospace vehicle application.

REFERENCES:

1. Fjelstad, Joseph, "Past, Present and Future of Solderless Assembly," Verdant Electronics, Pan Pacific Symposium, Sunnyvale, CA (2007).

2. Reggie Phillips, John Bultitude, Abhijit Gurav, Kitae Park, Sergio Murillo, Pamela Flores, and Mark Laps, "High Temperature Ceramic Capacitors for Deep Well Applications," ECA Symposium, Arlington VA., CARTS International Proceedings, March 25-28, 2013, Houston, TX.

3. Hinaga Scott, "Thermal Effects of PCB Laminate Materials Dialectric Constant and Dissipation Factor," Cisco Systems, San Jose, CA (2010).

KEYWORDS: printed circuit boards, high-temperature PWB, solderless connectors, high-temperature laminates, high-temperature solders, PWB

AF161-071

TITLE: High-Speed Measurements of Flame-Stabilization Processes in Vitiated Augmentor Environments for Understanding Screech, Rumble, and Blowoff

TECHNOLOGY AREA(S): Air Platform

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 high-repetition rate technique to measure velocity fields (three-velocity components and all nine-strain rate components) in bluff-body flames with sufficient temporal and spatial resolution for understanding flame stabilization processes.

DESCRIPTION: Combustion instabilities such as screech[1-3], rumble[1-3], and blowoff[4] are critical engineering challenges in augmentor design and operation. These transient processes are coupled sensitively to the flame anchoring physics which can be controlled by flame-propagation or auto-ignition[5]. There is currently minimal understanding of the coupling of these two critical combustion mechanisms which may be a sensitive function of augmentor operating conditions particularly during intermittent transient events such as ignition, transition to screech, or blowoff. Furthermore, predictive modeling and simulation of these events require detailed understanding of the localized flame anchoring physics. Currently, quantitative high-speed measurement techniques for capturing flame anchoring processes have insufficient spatial resolution and dimensionality for fully capturing the temporally and spatially evolving processes. Therefore, augmentor design practices, operability, and sustainability will benefit significantly from advances in high-resolution measurement capabilities for quantifying flame anchoring mechanisms.

In particular, it has been shown that flame propagation is dependent on the velocity field in the vicinity of the flame, the fluid dynamic strain-rate, and the dynamics of turbulence. In addition to the velocity field, the proposed effort will require spatial and temporal determination of the fluid dynamic strain-rate tensor, which necessitates measuring how all three-velocity components vary in all three spatial dimensions. The proposed effort should develop and apply a technique for high-speed measurements of the three dimensional, three-component velocity field (3D3C). For small measurement volumes, tomographic particle image velocimetry (PIV) is well suited for this measurement[6]. However, for larger domains (> 10 mm per side) sufficient illumination of the measurement volume becomes challenging while the smallest resolvable spatial scales are severely limited at the high repetition rates required (10 to 100 kHz). Stereoscopic PIV provides a planar measurement of the three-component velocity field, but cannot capture the out of plane velocity derivatives required in this effort. Other velocimetry techniques could be employed including “seedless” measurements such as molecular tagging velocimetry although extension to three dimensions and three components is required. However, the proposed technique must be capable of implementation in time-varying combusting flows without influencing the flame physics[7].

The proposed technique should be demonstrated in a vitiated augmentor combustion rig of practical interest (2200-3500 F), with spatio-temporally resolved measurements of the three-component velocity vector field. Accurate resolution of relevant temporal and spatial scales must be demonstrated for understanding the influence of flame anchoring physics on transient augmentor processes including blowoff, screech, and rumble. These measurements will lead to a physics-based understanding of dominant flame stabilization modes over a range of operating conditions. The results of this program will be an improvement to the diagnostics available for such measurements, and flame anchoring physics analyses that would be valuable to augmentor designers for enhancing operability, reliability, and sustainability.

Teaming/collaboration with a prime contractor/original equipment manufacturer (OEM) is encouraged to facilitate transition.

PHASE I: Demonstrate three-dimensional, three-component velocity measurements (3D3C) in an atmospheric-pressure lab-scale reacting flow (2200-3500 F). Demonstrate sufficient temporal and spatial resolution and dimensionality for quantifying the influence of flame anchoring mechanisms on transient processes including blowoff, screech, and rumble. Develop business case/transition plan.

PHASE II: Further develop and apply the technology demonstration in Phase I to a vitiated bluff-body stabilized flame test rig of practical interest and relevance to augmentors. Develop, apply, and deliver hardware and advanced physics-based data analysis tools for understanding screech, rumble and blowoff in vitiated augmentor environments.

PHASE III DUAL USE APPLICATIONS: High-repetition-rate measurement technologies demonstrated herein can be used in development and procurement programs for the collection of high-quality quantitative data for validation of design, operation, and performance of gas-turbine augmentors, combustors, and turbine test facilities.

REFERENCES:

1. Smith, D.A., and Zukoski, E.E., "Combustion Instability Sustained By Unsteady Vortex Combustion," AIAA/SAE/ASME/ASEE Joint Propulsion ConferenceMonterey, CA (1985)

2. Poinsot, T.J., Trouve, A.C., Veynante, D.P., Candel, S.M., and Esposito, E.J., "Vortex-driven acoustically coupled combustion instabilities," Journal of Fluid Mechanics, Vol. 177, pp. 265–292 (1987).

3. Soteriou, M.C., and Ghoniem, A.F., "The Vorticity Dynamics of an Exothermic, Spatially Developing, Forced Reacting Shear Layer," Proceedings of the Combustion Institute, Vol. 25, pp. 1265-1272 (1994).

4. Shanbhogue, S.J., Husain, S., and Lieuwen, T., "Lean blowoff of bluff body stabilized flames: Scaling and dynamics," Progress in Energy and Combustion Science, Vol. 35, pp. 98–120 (2009).

5. Lieuwen, T.C., "Unsteady Combustor Physics," Cambridge University Press (2012).

6. Elsinga, G.E., Scarano, F., Wieneke, B., and Oudheusden, B.W.v., "Tomographic particle image velocimetry," Experiments in Fluids, Vol. 41, pp. 933–947 (2006).

7. Böhm, B., Heeger, C., Gordon, R. L., and Driezler, A., "New Perspectives on Turbulent Combustion: Multi-Parameter High-Speed Laser Diagnostics," Flow, Turbulence and Combustion, Vol. 86, pp. 313–341 (2010).

KEYWORDS: thermoacoustic instabilities, lean blowoff, tomographic particle image velocimetry, high-speed combustion diagnostics

TECHNOLOGY AREA(S): Air Platform

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: Demonstrate feasibility of combining a heat exchanger and structural wall of an aircraft propulsion inlet, fan and/or auxiliary fan stream case to reduce overall system weight and cold flow pressure losses while satisfying cooling requirements.

DESCRIPTION: Ongoing efforts are taking place to improve aircraft propulsion system performance with goals such as decreased fuel consumption, longer range and/or sustained high-speed flight. To accomplish these goals, higher turbine temperatures and rotating shaft speeds, among other things, are necessary to reach required cycle efficiencies and thrust-to-weight ratios. To obtain the necessary high temperatures, cooling of turbine blades beyond internal blade cooling is often required to maintain structural integrity. An approach to accomplish this is to provide cooled cooling air (CCA) into the first few stages of the high-pressure turbine (HPT). To provide the cooling air for the HPT, CCA system heat exchangers are employed. Temperature control of various subsystems for both the propulsion system and aircraft are also prevalent within air platforms, most of which utilize heat exchangers. The potential for providing heat exchangers for the aircraft’s power and thermal management system (PTMS) within the engine’s fan and/or auxiliary fan stream opens opportunities for increased cooing capability beyond current systems.

Available space for various accessories for both the aircraft and propulsion system is typically at a premium. In addition, the weight of the accessories often comes at a penalty to system weight goals. Great measures are taken to find ways to reduce both size and weight, while providing the desired performance. Heat exchangers typically attached to or within the engine, are no exception. As there are numerous heat exchangers (e.g., air/air, fuel/air and fuel/oil) associated with the propulsion system and aircraft, reductions in weight can lead to overall system weight reduction. One potential approach to accomplishing this is to combine a heat exchanger(s) with the engine structure. This means that the heat exchanger becomes a structural member and provides the heat transfer necessary to meet cooling requirements in the range of 30kW to 1mW, material temperatures range from 300 to 1600 degrees F and pressure losses of less than five to ten percent. To become a structural member, the heat exchanger must be able to withstand structural loads, thermal and structural stresses, cycle fatigue, life, pressures, and temperatures required of typical engine casing. The design must also cost effectively address reliability, maintainability and safety. Material selection will be a key factor in the heat exchanger design, both structurally and manufacturability, in addition to having the appropriate heat transfer characteristics, such as thermal conductivity, fluid compatibility and similar coefficient of thermal expansion as the surrounding structure material. From a heat exchanger performance viewpoint, having high volumetric effectiveness and appropriate level of heat rejection capability will be paramount. Other performance factors that come into play are surface area, heat transfer coefficients, flow rates and pressure losses that meet cooling requirements, as a minimum. Additional considerations for heat exchanger design to be considered, but not limited to are, overall effectiveness, attachment mechanisms, plumbing connections, accessibility, maintainability, reliability, repairability, manufacturability, and cost. Potential risks and mitigation approaches should be identified.

Coordination and/or partnership with an original equipment manufacturer (OEM), first tier subsystem company and/or weapons system company (WSC) in order to gain insight into realistic operational requirements (such as heat transfer medium(s), flow rates, temperatures, pressures, effectiveness, structural requirements, life, reliability, etc.) and constraints (size, weight, costs, potential installation locations, attachment methods, material compatibility, etc.) is highly encouraged.

PHASE I: Determine feasibility of an aircraft propulsion inlet, fan duct, and/or third stream fan case structurally embedded heat exchanger. As a minimum, identification of design features and properties (materials, structural needs, etc.) are an expected outcome. Develop business case/transition plan, and preliminary design with analytical details describing path forward.

PHASE II: Use Phase I results to develop a detailed design leading to the construction, test, and pre- and post-test result analysis of a sub- or full scale structural embeddable heat exchanger prototype. Identify methods to minimize size and weight while ensuring robustness and reliability for potential application in aircraft propulsion systems. In addition, identify development efforts required to advance the technology to Technology Readiness Level 6. Refine business case/transition plan.

PHASE III DUAL USE APPLICATIONS: Military application: Weapon systems that currently have propulsion system fan duct heat exchangers, and new weapon systems needing additional vehicle, subsystem and/or propulsion system cooling. Commercial application: Commercial aircraft, trucks and/or autos needing more cooling with little space.

REFERENCES:

1. Department of Defense Handbook – Engine Structural Integrity Program (ENSIP), MIL-HDBK-1783B w/CHANGE 2, 22 September 2004.

2. Shah, R.K. and Sekulic, Dušan P., "Fundamentals of Heat Exchanger Design," John Wiley & Sons, Inc., Hoboken, NJ, 2003.

KEYWORDS: heat exchanger, thermal management, aircraft propulsion system, power and thermal management, structure, material, weight savings, temperature, pressure loss