2. King, C.R. (1957). A Semi-empirical Correlation of Afterburner Combustion Efficiency and Lean-Blowout Fuel-Air-Ratio Data with Several Afterburner-Inlet Variables and Afterburner Length. National Advisory Committee for Aeronautics. NACA RM E57F26
3. DeZubay, E. A. (1950). Characteristics of Disk-Controlled Flame. Aero Digest. 61, 1, 54-56, 102-104.
4. Adelman, H. G. (1981). A Time Dependent Theory of Spark Ignition. The Proceedings of the Combustion Institute. 1333-1342.
5. Drake M. C., Fansler, T. D., & Lippert A. M. (2005). Stratified-charge combustion: modeling and imaging of a spray-guided direct-injection spark-ignition engine. Proceedings of the Combustion Institute. 30, 2683-2691.
6. Dahms R., Fansler, T. D., Drake, M. C., Kuo, T. W., Lippert, A. M., & Peters, N. (2009). Modeling ignition phenomena in spray-guided spark-ignited engines. Proceedings of the Combustion Institute. 32, 2743-2750.
7. Sforzo,B., Kim, J., Seitzman, J.M., & Jagoda, J. (2011). Spark Kernel Energy and Evolution Measurements for Turbulent Non-Premixed Ignition Systems. Augmentor Design Systems Conference. Ponte Verda Beach, FL, March 16-18.
8. Sforzo, B., Kim, J., Lambert, A., Jagoda, J., Menon, S., & Seitzman, J. (2013). High Energy Spark Kernel Evolution: Measurement and Modeling. Proceedings of the 8th US National Combustion Meeting. May 19-22, 2013.
9. Department of Defense Joint Specification Service Guide (JSSG). (2007). Engines, Aircraft, Turbine. JSSG-2007B.
10. Wu, H, & Ihme, M. (2014). Effects of flow-field and mixture inhomogeneities on the ignition dynamics in continuous flow reactors. Combustion and Flame. 161, 9, 2317-2326.
KEYWORDS: Combustion; Ignition; direct replacement; plasma; chemical kinetics; augmentor
Questions may also be submitted through DoD SBIR/STTR SITIS website.
N151-017 TITLE: Adaptive Scanning for Compressor Airfoils
TECHNOLOGY AREAS: Air Platform, Materials/Processes, Sensors
ACQUISITION PROGRAM: JSF-Prop
OBJECTIVE: Development of a commercialized measurement system for an integrally bladed rotor (IBR) and compressor blade inspection that will enable the accuracy of current commercial systems to be exceeded and will result in a reduction of measurement times.
DESCRIPTION: In the past several years, contact measurement systems have evolved from point, to line, to surface scanning methods. This evolution has led to an inherent decrease in scanning time for mapping the profile of military-sized engine IBRs from 100s of hours to less than 10 hours. In addition to contact measurement systems, there have been non-contact measurement systems that utilize optics for airfoil characterization. The contact and optical measurement methods each have their limitations. Contact measurement systems are inherently slower and are susceptible to dynamic effects such as vibration. Optical measurement systems use a line-of-sight technique which has highest integrity when performing measurements normal to the measured surface which makes small IBR measurements possessing small passages and closely spaced airfoils cumbersome. Optical techniques may be hindered by their susceptibility to characterize airfoils with high surface finish, as a smoother surface may saturate the receiving optics with diffused light. Airfoils with a “super-polished” finished are ideal for increased efficiency. A deficiency that both contact and optical methods exhibit is the inability to get accurate measurements of high-curvature entities, such as the leading and trailing edges of airfoils. It is the leading and trailing edge of airfoils that is considered the most critical with respect to geometry but also the most challenging to manufacture and thus the need for accurate inspection. Therefore, an innovative or hybrid singular system is necessary to accurately measure airfoil profiles, specifically high-curvature surfaces, while minimizing scan time.
The research will consist of two primary components. The first component of the research is system design. To increase measurement speed, it is expected that the solution will involve scanning of the desired airfoil sections that define the desired geometry. This will require extreme attention to the coordinated motion of multiple axes along with minimization / correction of geometric and positioning errors. The solution is recommended to be non-contact to eliminate speed-limiting, dynamic effects of the contact in conventional systems. The second component of the research is system control. A high-resolution, high bandwidth, non-contact probe has operating limits of angular orientation with respect to the surface being measured. Compressor airfoils have features with high curvature (e.g. leading and trailing edge) where the size of the feature is similar in magnitude to the location tolerance of the feature with respect to the overall part datum planes. These facts together mean that, in general, a multi-axis sensor path based on the nominal part geometry will not be sufficient to perform a successful measurement. A successful response will include a significant effort in the development of control algorithms including real-time signal conditioning, curve fitting, and optimization to quickly scan sections, IBRs and airfoils. These aspects of the research will certainly have implications to other applications and industries. Collaboration with engine/blade/IBR manufacturers to define system requirements and support commercialization is highly encouraged during all phases of the program.
PHASE I: Feasibility of measurement precision and measurement reduction time should be exhibited. Conceptual design for the final machine configuration should also be completed along with cost estimates. Assess the Technology Readiness Level (TRL)/Manufacturing Readiness Level (MRL) at the end of the Phase I base effort (and option, if applicable).
PHASE II: Detailed design, fabrication, and testing should be accomplished. Control algorithms should be optimized by tests on actual hardware. The optimization should include not only the control of the sensor for orientation but also, the use of redundant axes and location of probe with respect to rotational axis, taking into account part curvature to minimize inertial force. The result will be a functional working prototype and vehicle for future software/control revisions and testing. A fully functional prototype should be demonstrated and the TRL/MRL assessment updated. The final demonstration should be performed in a relative environment with the design incorporating basic commercial considerations such as safety and operator inputs.
PHASE III: The design and software should be fully functional and used for measurement of airfoils for axial compressors of propulsion systems (military and commercial) as well as for power turbines. Focus on certifying and qualifying the system for Navy use. Commercialize and transition the system to the Navy fleet, specifically the JSF platform. The measurement system will allow detailed post-manufacturing inspection in order to document manufacturing discrepancies and mitigate installation of flawed components within a reasonable duration.
PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: The equipment developed will be useful for measurement of airfoils for axial compressors of propulsion systems (military and commercial) as well as power turbines. This is a substantial market on its own. In addition, the developed adaptive scanning will have potential benefit to any industry and application where coordinate metrology is used. Measurement times may be reduced for aerospace, automotive, optical, medical, electronics, semiconductor, etc. applications.
1. Sohn, A., Garrard, K.P., & Dow, T.A. (2011). Four-axis Spherical Geometry Measurement of Freeform Surfaces – Polaris 3D. Proceedings of the 2011 ASPE Spring Topical Meeting. 511, 38-42. Retrieved from http://aspe.net/publications/Spring_2011/Spring%202011%20Proceedings.pdf
2. Sohn, A., Garrard, K.P., & Dow, T.A. (2005). Polar coordinate-based profilometer and methods. U.S. Patent No. 6,895,682. Washington, DC: U.S. Patent and Trademark Office.
3. DoD 5000.2-R, Appendix 6, pg. 204. Technology Readiness Levels and Their Definitions. http://www.acq.osd.mil/ie/bei/pm/ref-library/dodi/p50002r.pdf
4. Manufacturing Readiness Level (MRL) Deskbook, May 2011. http://www.dodmrl.com/MRL_Deskbook_V2.pdf
KEYWORDS: Inspection; Measurement; BLISK; IBR; MANUFACTURE; Compressor
Questions may also be submitted through DoD SBIR/STTR SITIS website.
N151-018 TITLE: Integrated Laser and Modulator
TECHNOLOGY AREAS: Air Platform, Sensors, Electronics
ACQUISITION PROGRAM: JSF-MS
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. 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 an integrated laser and intensity modulator for analog/radio frequency photonic links operating at 1.55 micron.
DESCRIPTION: Military communication systems on avionic platforms have very small size and low weight requirements. Fiber optic based links provide inherent advantages over electronic based systems due to ultra-wide bandwidth, immunity to electromagnetic interference and reduced weight. Despite the advantages provided by fiber optics, the size of an entire system is still limited by engineering tradeoffs such as the spacing required between components due to the fiber optic interfaces and the packaging size of individual components. Specifically, the required use of optical fiber between the laser and modulator limits the ability to create a compact transmit system. A standard system includes a laser, modulator and a photodiode receiver. Typically there is some active and/or passive signal processing that can be done post modulator, indicating that the laser and modulator are consecutive. Thus a small packaged integrated laser and modulator device is needed.
Recently low relative intensity noise (RIN) lasers and small form factor modulators have become commercially available. However, the challenges posed by integrating both components together in a very small form factor package without the aid of fiber has yet to be accomplished, as typically the laser and modulator are of differing materials. Some work has been done to integrate optical components monolithically [1, 2], and heterogeneously , but researchers have yet to demonstrate an integrated laser and modulator design at power levels needed for most radio frequency (RF)/analog photonic links.
RF/analog photonic links suffer from complexity and size since the components cannot be built on one chip. Avionic platforms, as well as radar applications, would benefit from a very compact integrated link. Integrated laser and intensity modulators operating at 1.55 micron are desired with a minimum linewidth requirement of less than (<) 200 kHz and ideally < 100 kHz, and relative intensity noise of < -169 dBc/Hz from DC to at least 20 GHz. The intensity modulator should have a 3 dB bandwidth of at least 20 GHz and ideally 40 GHz, with a radio frequency (RF) Vp < 3 V at 1 GHz, a reflection coefficient (S11) of < 15 dB and 25 mW output power when biased at quadrature. The extinction ratio is required to be > 20 dB but is desired to be > 25 dB. Typically, a laser and modulator interfaced via optical fiber are of different material types. The desired laser and modulator interface may be of the same or differing materials so long as the two are combined without the aid of optical fiber on a single chip, monolithically or heterogeneously. The integrated device should be designed such that dimensions in height and width are feasible for packaging at 1 cm by 1 cm with a length not to exceed 15 cm. Ideally, the dimensions should not exceed a packaging requirement of 5 mm by 5 mm by 10 cm for the integrated laser and modulator interface. The inputs should include a female K connector (2.92 mm) and bias control for the modulator, as well as laser bias and thermal electric cooler (TEC) control if necessary and a fiber output style ferrule connector (FC)/angled physical contact (APC) (FC/APC). Collaboration with an original equipment manufacturer (OEM) in all phases is encouraged, but not required, to assist in defining aircraft integration and commercialization requirements. TRL (Technology Readiness Level)/MRL (Manufacturing Readiness Level) assessments at the conclusion of each phase should be performed.
PHASE I: Design and analyze a new approach for an integrated laser and modulator device addressing the goals in the description. The approach to optical coupling or monolithic integration should be demonstrated in a bench top experiment as well as the electronic circuitry needed for RF and direct current (DC) bias and any temperature control if required. Perform modeling and simulation of the device and analyze required power handling and frequency requirements. Perform a proof-of-concept demonstration and a Technology Readiness Level (TRL)/Manufacturing Readiness Level (MRL) assessment.
PHASE II: Build, test and demonstrate a prototype heterogeneously integrated laser and modulator interface device with bench-top experiment showing 20 GHz bandwidth with 25 mW output power at quadrature and RF Vp of no more than 3 V at 1 GHz. Develop packaging suitable for transition to Navy aircraft applications and develop integration plan. Test prototype integrated laser and modulator in an RF photonic link with the objective performance levels reached. Characterize the packaged device over the full –40 to +100 degrees Celsius ambient temperature range. If necessary, perform root cause analysis and remediate packaged integrated laser and module failures. Deliver packaged laser prototypes on evaluation boards. Update TRL/MRL assessment.
PHASE III: Finalize packaging for transition to military and commercial applications. Develop plan and demonstrate capability to fabricate and package devices for military platforms and outline design for typical avionic ruggedness requirements. Perform final avionics integration activities and qualification testing. Demonstrate plan for device manufacturing.
PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: The technology would find application in commercial systems such as fiber optic networks and telecommunications.
1. Hou, L., Wang, W., Zhu, H., Zhou, F., Wang, L., & Bian, J. (2005). Monolithically integrated laser diode and electroabsorption modulator with dual-waveguide spot-size converter input and output. Semiconductor Science and Technology, 20, 779-782.
2. Sysak, M. N., Raring, J.W., Barton, J.S, Dummer, M., Blumenthal, D.J., & Coldren, L.A.. (2006). A Single regrowth integration platform for photonic circuits incorporating tunable SGDBR lasers and quantum-well EAMs. IEEE Photonics Technology Letters, 18, 15, 1630-1632.
3. Ahmed, T., Butler, T., Khan, A. A., Kulick, J. M., Bernstein, G.H., Hoffman, A.J., & Howard, S. S. (2013). FDTD modeling of chip-to-chip waveguide coupling via optical quilt packaging. Proc. Of SPIE, 8844.
4. Department of Defense. (2011). Technology Readiness Assessment (TRA) Guidance.