Agency: Department of Energy | Branch: | Program: STTR | Phase: Phase II | Award Amount: 999.94K | Year: 2015
New automotive engine technologies, such as direct injection with stratified charge combustion, are being explored under programs of the DOE and others that offer significant increases in efficiency and reductions in emissions. Research tools are needed to help determine how best to adequately control the combustion process throughout the engine operating envelope, to optimize combustion efficiency, and to prevent misfires and partial burn. Advanced fuel injector spray patterns can be complex, and quantitative measurements of the spray structure are needed, but current diagnostic systems lack the ability to measure fuel/air mixture distributions in the critical regions of the spray. MetroLaser, Inc. and the Ohio State University (OSU) are developing a diagnostic system that combines filtered Rayleigh scattering (FRS) with Mie scattering to allow imaging of both liquid and vaporized fuel simultaneously in a fuel injector spray. A sheet of laser light illuminates the region of interest and two cameras view the laser sheet, one employing FRS that blocks scattering from droplets to measure fuel vapor, and the other measuring Mie-scattered light from droplets to obtain the droplet distribution. In the Phase I, a model of the FRS signal was developed for various single-component hydrocarbon fuels, and was validated experimentally. Excellent agreement was seen between model and data for simple fuels, and results for more complex fuels were encouraging as well. Measurements were performed using the FRS/Mie technique in an evaporating fuel spray at room temperature and pressure, proving feasibility by demonstrating quantitative two- dimensional (2D) distributions of fuel/air mixture ratio and droplet distributions. In Phase II, the model will be extended to improve the accuracy for the more complex fuels, and will be validated by comparison with experimental data at thermodynamic conditions representative of an engine. A prototype FRS/Mie system will be constructed and developed in a constant flow spray facility at moderate pressure, and finally demonstrated on a fuel injector spray in a model combustion chamber at engine conditions. Commercial Applications and Other Benefits: The proposed diagnostic technique should help bring about significant improvements in energy efficiency, reduced fuel use, and reduced emissions in vehicles by providing engine designers with a tool to better quantify fuel injection dynamics. Boosting the efficiency of internal combustion engines is one of the most promising and cost-effective approaches to increasing vehicle fuel economy. This diagnostic system would provide a critically important capability needed to help achieve a 20 to 40 percent reduction in fuel use, which the DOE estimates can be attained through commercialization of advanced engines.
Agency: Department of Defense | Branch: Air Force | Program: STTR | Phase: Phase I | Award Amount: 149.98K | Year: 2015
ABSTRACT: An unseeded measurement technique is proposed for simultaneous spatially-resolved measurements of density, temperature, and velocity in hypersonic wind tunnel flows with the future potential for time-resolved measurement capability. A variant of filtered Rayleigh scattering (FRS) will be developed that takes advantage of unique monotonic relationships between molecular vapor cell filter transmissions and flow parameters of interest. The method relies on laser Rayleigh scattering from naturally present nitrogen or air molecules, and therefore requires no seeding of the flow. Thermodynamic properties of the test gas are obtained by measuring the transmission of Rayleigh scattered light through multiple vapor cell filters, which have sharp spectral cut-offs that can be tailored to provide good sensitivity to the properties of interest. A unique set of transmission coefficients, measured from images obtained with a camera, defines a given thermodynamic state, providing a non-intrusive instantaneous measurement. In the Phase I effort, we will demonstrate the technique with instantaneous measurements of density, temperature, and velocity along a line in a supersonic flow, laying the groundwork for later variants that will enable two-dimensional measurements of these quantities in various hypersonic flow fields, e.g., boundary layers, shock-wave/boundary layer interactions, and time-resolved measurements at high acquisition rates.; BENEFIT: The unique capability of filtered Rayleigh scattering (FRS) to measure flow fields, ranging from subsonic to hypersonic, with high spatial resolution is expected to be attractive to a wide range of customers, including U. S. and other governments test facilities, universities, and industrial testing sites. The FRS scheme described in this proposal can simultaneously measure multiple flow properties without the need for flow seeding, and hence represents an excellent diagnostic tool that can benefit vehicle designers and flow modelers. Some attributes of FRS having value to commercial aerospace interests include measurements supporting performance testing of advanced aircraft, rotorcraft, entry spacecraft such as Expendable Launch Vehicles (ELV) and Reusable Launch Vehicles (RLV), and propulsion concepts. Equal measurement capability is not readily available elsewhere in the world, thereby offering U.S. Government laboratories and the U.S. aerospace industry a unique capability for aerodynamic vehicle development. FRS is adaptable to applications in facilities of all sizes including those for full-scale model testing of aircraft and inlet flows, rotorcraft intra-blade and rotor-body wake interactions, vortex-control surface interactions, in-flight flows, propulsion system testing, and rocket test stand plumes. Another attractive feature of the FRS technique is the ability to measure temperature and density in turbulent flames and swirl combustors non-intrusively.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase II | Award Amount: 749.91K | Year: 2015
ABSTRACT:A non-destructive optical sensor and a computational model for quantifying and predicting damage caused by silica particle ingestion in gas turbine engines are proposed. The sensor is based on optical coherence tomography (OCT), which in Phase I was shown to be sensitive to infiltration of calcium magnesium alumino-silicate (CMAS) into thermal barrier coatings (TBCs). In Phase II, a refined prototype sensor will be developed and used to measure the extent of CMAS infiltration of a range of test specimens and ex-service turbine blades and vanes. The accompanying model simulates the infiltration of molten CMAS into a porous TBC under non-uniform and transient temperature conditions, including the viscous flow, partial crystallization, and resulting strain of a given molten mineral deposit. The combination of sensor and model allows testing of predictions and subsequent development and use as a decision support tool for evaluation of the remaining life of critical engine components involving TBCs.BENEFIT: The proposed sensor system and damage model together enable predictions of remaining life of turbine blades and vanes that have been exposed to sand and/or volcanic ash environments. The combined product is envisioned to serve as a decision support tool for both military and civilian aircraft maintenance personnel. The envisioned OCT sensor system will be a valuable diagnostic tool for on-wing inspection of in-service engines to obtain non-destructive evaluations of CMAS infiltration level with improved assessments of damage. Researchers could use the diagnostic for rapid and efficient screening of advanced TBCs through non-destructive testing. Validated damage models will enable prediction of CMAS infiltration and crystallization dynamics, which provides a useful tool for testing and evaluation of CMAS mitigation strategies.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 749.99K | Year: 2016
A suite of pulsed laser diagnostics is proposed for studying aspects of planetary entry and Earth atmospheric reentry in arc jets. For example, dissociation of molecules impacts the flow-field physics, including surface heat flux and catalytic surface reactions. Results obtained during the Phase I effort point to three promising diagnostic techniques: Rayleigh Scattering Polarimetry (RSP) for dissociation fraction, Thermal Acoustic Wave (TAW) thermometry for gas temperature, and Radar Resonance Enhanced Multi-photon Ionization (Radar REMPI) for gas temperature and velocity. The RSP technique is based on the differences in the polarization of Rayleigh-scattered light between atoms and molecules. The TAW technique is based on the determination of wave speed from the propagation of an acoustic wave generated by a laser spark from the focused beam of a pulsed laser. In the case of Radar REMPI, temperature and velocity are obtained through the spectral broadening and frequency shift associated with two-photon resonance interactions in atomic oxygen and nitrogen.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 124.95K | Year: 2015
A suite of laser-based diagnostics is proposed to measure velocity and temperature simultaneously using unseeded techniques in high enthalpy flows relevant to reentry flight. The two main types of regions that are found in a typical hypersonic flow field around a vehicle are addressed by developing separate diagnostics for each. In regions far from the body where the flow is mostly non-dissociated, femtosecond laser electronic excitation tagging (FLEET) is proposed for velocity combined with planar Rayleigh scattering to measure temperature via the imaging of an acoustic wave triggered by the FLEET pulse. In the highly dissociated region near the stagnation point of the reentry body, either backward air lasing or radar REMPI will be applied to spectrally resolve a transition of atomic oxygen. The latter two techniques use the same two-photon excitation scheme, but backward air lasing relies on a population inversion induced in the measurement volume, and radar REMPI relies on the microwave interrogation of an induced plasma. The goal of the Phase I study will be to determine which of these two techniques provides the best signal-to-noise ratios in the dissociated regions, and to establish the performance of the combined FLEET/Rayleigh scattering method in the non-dissociated regions.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 224.97K | Year: 2015
The problem is to develop a compact instrument to measure cloud droplet-drizzle in the range of 10 to 1,000 m from unmanned airborne vehicles (UAVs) (such as the ScanEagle or Puma) in the Arctic and Antarctic regions. As stated in the SBIR solicitation, traditional packages are too large and heavy for this application. The instrument should have little or no pressure control, weigh less than 5 kg and operate with under 50 watts. Statement of How this Problem or Situation is Being Addressed We propose to develop a digital scanning holographic camera for atmospheric particle sampling. Airborne holography systems have flown successfully for many years (by the current proposers and others); however, the current requirement cannot be met by existing systems because of size and weight restrictions. With a UAV, the diffraction field moves over the detector array. We propose to exploit that movement, allowing the object field to sweep the diffraction pattern over a linear detector array, a principle that is already proven in digital holography. The linear detector array samples and digitizes the diffraction pattern of the particles as they move over the array, producing the same information that can be captured on a two-dimensional array, but doing it continuously. Linear arrays can be operated much faster than two-dimensional arrays, are easier to protect using smaller windows, and require less weight and power to operate. Data from extremely large sample volumes can be stored on a small memory card and processed by computer later. The project will enable digital holography from balloons and unmanned airborne vehicles (UAVs) with unique concepts that can reduce the camera size and power requirement, increase the sample volume, and process data more efficiently. This will represent a major advance in the art of digital particle holography. The proposed concept adds capabilities that are not currently available, such as accurate concentration measurements. Since holograms contain 3-D position information, a holocamera will outperform most existing instrumentation in concentration and size measurement. MetroLaser, Inc. Topic 19.a A New Airborne Weather Instrument Based on Digital Holography 2 P1421DEJT_Summary Commercial Applications and Other Benefits The proposed diagnostics tool will have many applications in future meteorology experiments, providing investigators a presence in extremely remote locations via a virtual holographic window. The proposed instrument would enable measuring clouds and aerosols in the Arctic and Antarctic regions, which play a significant role in the prediction of global warming. In addition to atmospheric measurements, the proposed instrument would be applicable to numerous commercial applications associated with sprays such as combustion engine injector design, agricultural spray characterization, and the characterization and design of spray fire extinguishers. Key Words Particle sizing, cloud characterization, airborne, digital holography Summary for Members of Congress New instruments are needed to more accurately characterize the atmosphere and provide critical data for climate science. This work specifically addresses the need for ice, water, and other particle measurements in the atmosphere, especially in the Arctic and Antarctic regions. Compact instruments that can be deployed in unmanned aerial vehicles are needed to measure cloud particles in the range of 10 to 1,000 m. Traditional instruments are too large and heavy for this application. The instrument should have little or no pressure control, weigh less than 5 kg and operate with under 50 watts. One of the most powerful particle field characterization tools is 3D holography, which allows a researcher to examine and characterize microscopic particles in large volumes. Traditional systems, though powerful in capability are much too large and heavy and consume too much power to be deployed in UAVs. However, in recent years, the emergence of digital optics and electronics changes this situation entirely. Digital holography records holograms electronically and stores them in memory cards. Particle field images are reconstructed electronically by high speed computers. It should be possible to incorporate these methods into a small, rugged, lightweight, low power instrument that is capable of providing critical measurements that are not provided by any other technology. The objective of this research is to prove the feasibility of such an instrument in Phase I and to construct and field it in Phase II.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 124.97K | Year: 2016
To measure the broad size range of 0.1 micron to 200 micron, we propose an optical instrument that combines two techniques: Forward scattering light intensity (FSLI) and digital holography (DH). FSLI will provide the size and concentration of particles in the 0.1 to 5 micron range while DH will provide the size, concentration and shape of particles larger than 5 micron. Accurate measurements with FSLI rely on precisely knowing the intensity of the illumination beam at the position of the particle. An innovative fiber optic bundle will select for measurement the particles that cross the very center of the illumination beam where the intensity is uniform and known. The proposed DH strategy will employ small CCD with fast data transfer to enable continued scanning of the atmosphere over many meters or even hundreds of meters. Both technologies will employ small, low power components making them suitable for UAV operation. The Phase I work will include modeling and experimental demonstrations culminating with the conceptual design of a field prototype system.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 124.94K | Year: 2016
This is a proposal to develop a unique, gated, picosecond, digital holography system for characterizing dense particle fields in high pressure combustion environments; a critical requirement clearly defined in the NASA solicitation. Most imaging methods fail to provide this capability because noise from multiple scattering buries the signal needed to acquire a useful image. Solutions to this problem are expensive, difficult to implement, and not ideal candidates for field experiments. The proposed innovation combines digital holography and picosecond, optical gating to limit the amount of optical noise sufficiently to enable high resolution, 3D imaging, effectively generalizing existing pseudo-ballistic imaging systems that have been used for imaging through dense particle fields. Storing the complete wavefront in a hologram enables use of a wide range of optical diagnostics methods including image processing and interferometry to improve image and information quality. The result is a new sensor concept that will be extremely useful in the experimental study of dense sprays and other particles fields, providing a detailed, instantaneous look at the structure and position of all of the particles as well as density field information in a large three dimensional sample volume. Moreover, the system can record dynamic information at high frequency.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 124.95K | Year: 2016
An instrument is proposed for non-intrusive measurements of velocity in the plume of a large rocket engine of the type used in the first or second stage of a launch vehicle. The method is laser-based and has the potential for standoff distances in the tens of meters, so optical components can be a safe distance from the hot gases. The diagnostic does not require flow seeding, works over the full temperature range, and covers the full range of velocities of a typical rocket engine. The method, hydroxyl tagging velocimetry (HTV), has already been successfully demonstrated on a small rocket engine. The proposed effort will adapt this technique to large engines by minimizing the effects of beam attenuation and beam steering due to turbulence and developing a robust beam delivery and detection system. Because OH molecules survive at high temperatures for appreciable lifetimes, it is anticipated that the HTV technique will work in even the highest temperature rocket plumes. The proposed diagnostic will provide measurements not obtainable by current methods and will enable experimental data that can be used for validating computer models of rocket engine performance.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 124.89K | Year: 2016
Three diagnostic methods are proposed for measuring properties of interest in the post-shock regions of a hypersonic bow shock wave that is used for studying planetary entry and earth reentry flows. Shock location is measured using an imaging approach by laser Rayleigh scattering from molecules, shock velocity is measured by beam deflection via schlieren effects, and electron number density is measured by Thomson scattering. The Rayleigh and Thomson scattering methods are complimentary to each other and can use the same pulsed laser. The schlieren deflection is accomplished with a continuous wave laser and can be used to generate a precise arrival time and provide triggering for the pulsed laser. Thomson and Rayleigh scattering imaging may be extended to MHz rates with pulse burst laser technology, providing a capability to time-resolve the motion of the shock wave as it passes through the test section. The electron density measurement is a direct technique with the potential for high accuracy time and space-resolved measurements. The Phase I effort will demonstrate all three techniques in laboratory environments at relevant conditions.