Results for “laser-based” — Page 17

NASA NTRSDate not supplied

Measurements and Computations of the Turbulent Corner Flow on the NASA Juncture-Flow Model with a Symmetric Wing

The NASA Juncture Flow experiment is designed to acquire high-quality flowfield data deep in the corner of a wing-fuselage junction specifically for the purpose of computational fluid dynamics (CFD) validation and turbulence model improvement. This paper presents and discusses the results of a recent experiment with the juncture-flow model in the NASA Langley 14- by 22-Foot Subsonic Tunnel. The main objective of the test was to expand the existing juncture-flow dataset with a symmetric wing case that displays fully attached, incipient separation, and separated flow in the corner of the wing-fuselage junction, depending on the model angle of incidence. Laser Doppler velocimetry (LDV) measurements were made at three model angles of incidence (0 deg: fully attached, 1 deg: incipient separation, and 5 deg: separated flow) and for each one, mean-flow and Reynolds-stress data were obtained on the fuselage and at several streamwise locations along the corner of the wing-fuselage junction. Supporting measurements were made during the test campaign and included model and tunnel wall static pressures, tunnel wall and ceiling boundary-layer rake data, oil-flow visualizations, and laser-based measurements of the as-built model geometry and model position in the test section. Comparisons between the experimental data on the test article and Reynolds-averaged Navier-Stokes CFD results are presented and discussed.

Juncture Flow↗

NASA NTRSDate not supplied

Advanced Diagnostics for Megahertz Imaging of Mixing, Fuel Spray, and Combustion Processes for Rotating Detonation Combustors

Recent advancements in megahertz rate, high-power, burst-mode laser technology are leveraged to perform and explore imaging measurements that spatially and temporally resolve the mixing, combustion, and detonation flow field in two laboratory-scale rotating detonation combustors (RDCs). In a non-premixed annular RDC, multiple imaging diagnostics are explored to investigate gaseous and liquid injector behavior, the detonation wave structure, and the propellant refill. In one instance, OH planar laser-induced fluorescence (OH-PLIF) imaging is performed up to a 2 MHz repetition rate to track the combustion products and reaction zone locations. In the same annular RDC, a single liquid fuel jet is injected, and laser-based 355-nm imaging of the fuel spray is performed up to a 1 MHz repetition rate. For this configuration, the annular RDC is used as a detonation driver to impose periodic detonation waves to interact with the fuel spray. Moreover, in this annular RDC, a range of tracer-based laser imaging measurements are explored to time-resolve the unsteady oxidizer air recovery and refill process. In a non-premixed linear RDC, planar imaging measurements of the fuel mixing are performed up to a 200 kHz repetition rate using PLIF of a tracer in the fuel supply. The fuel mixing imaging helps explain the origin of the observed pre and post wave burning, detonation structure, and enables quantifying injector recovery timescales. This paper will provide a high-level broad survey of diagnostics applied in these RDCs, lessons learned, and interesting observations.

Combustion↗

NASA NTRS2023

Measurements and Computations of the Turbulent Corner Flow on the NASA Juncture-Flow Model with a Symmetric Wing

The NASA Juncture Flow experiment is designed to acquire high-quality flowfield data deep in the corner of a wing-fuselage junction specifically for the purpose of computational fluid dynamics (CFD) validation and turbulence model improvement. This paper will present and discuss the results of a recent experiment with the juncture-flow model in the NASA Langley 14- by 22-Foot Subsonic Tunnel. The main objective of that test was to expand the existing juncture-flow dataset with a symmetric wing case that displays fully attached, incipient separation, and separated flow in the corner of the wing-fuselage junction, depending on the model pitch angle. Laser Doppler velocimetry (LDV) measurements were made at three model pitch angles (0 deg: fully attached, 1 deg: incipient separation, and 5 deg: separated flow) and for each one, mean-flow and Reynolds-stress data was obtained on the fuselage and at several streamwise locations along the corner of the wing-fuselage junction. Supporting measurements were made during the test campaign and included model and tunnel wall static pressures, tunnel wall and ceiling boundary-layer rake data, oil-flow visualizations, and laser-based measurements of the as-built model geometry and model position in the test section. Comparisons between the experimental data and Reynolds averaged Navier-Stokes CFD results will also be presented and discussed.

Juncture Flow↗

NASA NTRSDate not supplied

Advanced Diagnostics For Megahertz Imaging Of Mixing, Fuel Spray, And Combustion Processes For Rotating Detonation Combustors

Recent advancements in megahertz rate, high-power, burst-mode laser technology are leveraged to perform and explore imaging measurements that spatially and temporally resolve the mixing, combustion, and detonation flow field in two laboratory-scale rotating detonation combustors (RDCs). In a non-premixed annular RDC, multiple imaging diagnostics are explored to investigate gaseous and liquid injector behavior, the detonation wave structure, and the propellant refill. In one instance, OH planar laser-induced fluorescence (OH-PLIF) imaging is performed up to a 2 MHz repetition rate to track the combustion products and reaction zone locations. In the same annular RDC, a single liquid fuel jet is injected, and laser-based 355-nm imaging of the fuel spray is performed up to a 1 MHz repetition rate. For this configuration, the annular RDC is used as a detonation driver to impose periodic detonation waves to interact with the fuel spray. Moreover, in this annular RDC, a range of tracer-based laser imaging measurements are explored to time-resolve the unsteady oxidizer air recovery and refill process. In a non-premixed linear RDC, planar imaging measurements of the fuel mixing are performed up to a 200 kHz repetition rate using PLIF of a tracer in the fuel supply. The fuel mixing imaging helps explain the origin of the observed pre and post wave burning, detonation structure, and enables quantifying injector recovery timescales. This paper will provide a high-level broad survey of diagnostics applied in these RDCs, lessons learned, and interesting observations.

Combustion↗

NASA NTRSDate not supplied

Measurements and Computations of the Turbulent Corner Flow on the NASA Juncture-Flow Model with a Symmetric Wing

The NASA Juncture Flow experiment is designed to acquire high-quality flowfield data deep in the corner of a wing-fuselage junction specifically for the purpose of computational fluid dynamics (CFD) validation and turbulence model improvement. This paper will present and discuss the results of a recent experiment with the juncture-flow model in the NASA Langley 14- by 22-Foot Subsonic Tunnel. The main objective of that test was to expand the existing juncture-flow dataset with a symmetric wing case that displays fully attached, incipient separation, and separated flow in the corner of the wing-fuselage junction, depending on the model pitch angle. Laser Doppler velocimetry (LDV) measurements were made at three model pitch angles (0 deg: fully attached, 1 deg: incipient separation, and 5 deg: separated flow) and for each one, mean-flow and Reynolds-stress data was obtained on the fuselage and at several streamwise locations along the corner of the wing-fuselage junction. Supporting measurements were made during the test campaign and included model and tunnel wall static pressures, tunnel wall and ceiling boundary-layer rake data, oil-flow visualizations, and laser-based measurements of the as-built model geometry and model position in the test section. Comparisons between the experimental data and Reynolds averaged Navier-Stokes CFD results will also be presented and discussed.

Juncture Flow↗

NASA NTRS2023

A 3D Printable Alloy Designed for Extreme Environments

Multiprincipal-element alloys are an enabling class of materials owing to their impressive mechanical and oxidation-resistant properties, especially in extreme environments. Here we develop a new oxide-dispersion-strengthened NiCoCr-based alloy using a model-driven alloy design approach and laser-based additive manufacturing. This oxide-dispersion-strengthened alloy, called GRX-810, uses laser powder bed fusion to disperse nanoscale Y 2 O 3 particles throughout the microstructure without the use of resource-intensive processing steps such as mechanical or in situ alloying. We show the successful incorporation and dispersion of nanoscale oxides throughout the GRX-810 build volume via high-resolution characterization of its microstructure. The mechanical results of GRX-810 show a twofold improvement in strength, over 1,000-fold better creep performance and twofold improvement in oxidation resistance compared with the traditional polycrystalline wrought Ni-based alloys used extensively in additive manufacturing at 1,093 °C. The success of this alloy highlights how model-driven alloy designs can provide superior compositions using far fewer resources compared with the ‘trial-and-error’ methods of the past. These results showcase how future alloy development that leverages dispersion strengthening combined with additive manufacturing processing can accelerate the discovery of revolutionary materials.

Timothy M. Smith↗

NASA NTRS2023

Moon-to-Mars Planetary Autonomous Construction Technology: MMPACT Material Screening

NASA’s Space Technology Mission Directorate “champions technologies needed to live on and explore the Moon” [1]. This includes capabilities that capitalize on existing lunar resources and carry out surface manufacturing and construction activities. The goal of the Moon-to-Mars Planetary Construction Technology (MMPACT) Project is to mature these two capabilities. The primary resource on the Moon and the primary feedstock for manufacturing and construction is regolith. In the past, astronauts launched, landed, and lived in a spacecraft. NASA envisions a future where we make living spaces on the lunar surface instead. The innovative technologies required for lunar surface construction may be something never seen before, or they may be adaptations of existing technologies. MMPACT must screen for the most feasible technologies with the earliest potential technology insertions given the ambitious goals of the Artemis campaign. This poster summarizes recent efforts to discover and document mechanical and thermal capabilities of various technologies: a laser-based vitreous material transformation from Texas-based ICON, a molten extrusion process from ICON, a mortar from MSFC, a mortar from an MSFC-Louisiana State University partnership, and a geopolymer from a MSFC-Pennsylvania State University partnership. Other testing and development activities are documented as well. [1] https://www.nasa.gov/directorates/spacetech/Lunar_Surface_Innovation_Initiative

In-situ Resource Utilization↗

NASA NTRS2023

Quantitative Gas Property Measurements By Filtered Rayleigh Scattering: A Review

Filtered Rayleigh scattering (FRS) is a laser-based diagnostic technique used to nonintrusively quantify various thermodynamic properties of a light-scattering gas. The backbone of FRS is the molecular filtering of Rayleigh scattered light. This concept was initially introduced by the atmospheric LIDAR community before being adopted within the aerospace research field in the early 1990s. Since then, FRS has matured into a versatile quantitative diagnostic tool and has found use in a variety of flow regimes ranging from sub- to supersonic speeds in both reacting and nonreacting environments. This adoption can be attributed to the wealth of information that can be obtained via FRS, including the gas density, pressure, temperature, velocity, species composition, or, in some cases, several of these properties at once. This article reviews the current state of FRS methodology in recovering such gas properties. As knowledge of the fundamentals of Rayleigh scattering and spectral light filtering is crucial to the design of an FRS experiment, we begin by briefly reviewing these areas. Subsequently, we conduct a survey of experimental design strategies, assumptions, and data reduction methods used to measure different gas properties using FRS. We conclude the review with a short discussion on quantification of experimental uncertainty and future trends in FRS.

filtered Rayleigh scattering↗

NASA NTRSDate not supplied

Moon-to-Mars Planetary Construction Technology (MMPACT) Scoop, Tamp, Filter (STF) Sub-System

NASA’s Space Technology Mission Directorate “champions technologies needed to live on and explore the Moon” [1]. This includes capabilities that capitalize on existing lunar resources and carry out surface manufacturing and construction activities. The goal of the Moon-to-Mars Planetary Construction Technology (MMPACT) Project is to mature these two capabilities. The primary resource on the Moon and the primary feedstock for manufacturing and construction is regolith. In the past, astronauts launched, landed, and lived in a spacecraft. NASA envisions a future where we make living spaces on the lunar surface instead. The innovative technologies required for lunar surface construction may be something never seen before, or they may be adaptations of existing technologies. This paper summarizes recent efforts to develop and test a scoop, tamp and filter (STF) sub-system to prepare and deposit lunar regolith for a laser-based vitreous material transformation system being developed under a NASA contract by ICON, inc., which is hoped to eventually be used for automated additive construction with indigenous regolith on the Moon.

Moon↗

NASA NTRSDate not supplied

Flow Visualization for Plume-Surface Interaction Testing Within Large-Scale Vacuum Environments at Conditions Relevant to Lunar and Martian Landers

Interactions between rocket exhaust plumes and the landing surface during powered spacecraft descent on the Moon and Mars pose significant risks to the landing vehicle, landing site, and nearby infrastructure. Understanding the underlying plume-surface interaction phenomena through ground test data can provide critical insights on the sensitivities of parameters such as the spacecraft altitude and thrust. In the present work, we summarize a scaled ground test recently conducted within a 20-ft vacuum chamber environment located in the historical East Test Area at the NASA Marshall Space Flight Center. The ground test featured a Mach 5.3 inert gas plume impinging upon an instrumented flat plate. Planar laser-induced fluorescence, which is a 2D laser-based flow field measurement technique, was performed at this test area for the first time to visualize salient flow features such as the barrel shock, stagnation shock, and wall jet. Measurements were obtained at discrete lander altitudes, made dimensionless using the nozzle exit diameter, corresponding to h/D = 10, 8, 5, 4, 3, and 2. The stagnation pressures of the plume were varied from approximately 0.04 to 1 MPa, providing sensitivity to the engine thrust of a powered spacecraft. The unique test facility allowed for near-lunar conditions to be obtained at initial vacuum chamber pressures less than 0.1 Pa. Martian-relevant measurements were also performed at ambient pressures near 600 Pa. Furthermore, a third set of measurements were obtained at so called lunar-relevant conditions near 3 Pa chamber pressure

Plume Surface Interaction↗

NASA NTRSDate not supplied

Flow Visualization for Plume-Surface Interaction Testing Within Large-Scale Vacuum Environments at Conditions Relevant to Lunar and Martian Landers

Interactions between rocket exhaust plumes and the landing surface during powered spacecraft descent on the Moon and Mars pose significant risks to the landing vehicle, landing site, and nearby infrastructure. Understanding the underlying plume-surface interaction phenomena through ground test data can provide critical insights on the sensitivities of parameters such as the spacecraft altitude and thrust. In the present work, we summarize a scaled ground test recently conducted within a 20-ft vacuum chamber environment located in the historical East Test Area at the NASA Marshall Space Flight Center. The ground test featured a Mach 5.3 inert gas plume impinging upon an instrumented flat plate. Planar laser-induced fluorescence, which is a 2D laser-based flow field measurement technique, was performed at this test area for the first time to visualize salient flow features such as the barrel shock, stagnation shock, and wall jet. Measurements were obtained at discrete lander altitudes, made dimensionless using the nozzle exit diameter, corresponding to h/D = 10, 8, 5, 4, 3, and 2. The stagnation pressures of the plume were varied from approximately 0.04 to 1 MPa, providing sensitivity to the engine thrust of a powered spacecraft. The unique test facility allowed for near-lunar conditions to be obtained at initial vacuum chamber pressures less than 0.1 Pa. Martian-relevant measurements were also performed at ambient pressures near 600 Pa. Furthermore, a third set of measurements were obtained at so called lunar-relevant conditions near 3 Pa chamber pressure.

Plume Surface Interaction↗

NASA NTRSDate not supplied

Review of planar laser-induced fluorescence measurements in the NASA Langley 31-Inch Mach 10 Air Tunnel

In 2003 a mobile planar laser-induced fluorescence (PLIF) system was constructed at NASA Langley Research Center to visualize and quantify high speed flow fields containing fluorescent species such as nitric oxide (NO). Thereafter, a series of test entries utilizing NO PLIF were conducted in the NASA Langley Research Center’s 31 Inch Mach 10 air wind tunnel, which is a hypersonic blowdown wind tunnel located in Hampton, Virginia. This paper briefly reviews laser-based measurements previously performed in hypersonic blowdown wind tunnel facilities and then details NO PLIF measurement campaigns performed at this facility in the 20 years to date. Measurements were performed to develop 2D and 3D visualization capabilities and quantitatively measure velocity and temperature. Applications described herein include historical models (e.g., Apollo, X-33 and X-43), flight vehicles under development at the time (e.g., Mars Science Lab (MSL), Orion, and LOFTID), as well as fundamental research (e.g., flat plates with and without discrete roughness).

PLIF↗

NASA NTRS2024

Measurements and Computational Analysis of the Turbulent Corner Flow on the NASA Juncture-Flow Model with a Symmetric Wing

The NASA Juncture Flow Experiment is designed to acquire high-quality flowfield data deep in the corner of a wing-fuselage junction for the purpose of computational fluid dynamics (CFD) validation and turbulence model improvement. This report presents and discusses the results of a recent experiment with the Juncture Flow Model in the NASA Langley 14- by 22-Foot Subsonic Tunnel. The main objective of the test was to expand the existing juncture-flow dataset with a symmetric wing case that displays fully attached, incipient separation, and separated flow in the corner of the wing-fuselage junction, depending on the model angle of incidence. Laser Doppler velocimetry (LDV) measurements were made at three model angles of incidence (0° : fully attached, 1° : incipient separation, and 5° : separated flow) and for each angle, mean-flow and Reynolds-stress data were obtained on the fuselage and at several locations along the corner of the wing-fuselage junction. Supporting measurements were made during the test campaign and include model and tunnel wall static pressures, tunnel wall boundary-layer profiles, oil-flow visualizations, and laser-based measurements of the as-built model geometry and model position in the test section. A companion set of Reynolds-averaged Navier-Stokes (RANS) CFD simulations were also performed and those results were used to support the discussion of the experimental test results.

Juncture Flow↗

NASA NTRSDate not supplied

Laser Forming of Sheet Metal for In-Space Manufacturing Applications

As the in-space economy matures, the migration of typically Earth-bound manufacturing methods, such as metal forming and joining, up to space will be required to meet the increasing demand for refueling and supply depots, habitats, laboratories, lunar surface structures, and sites for deep-space exploration shipbuilding. Only in this way can the magnitude of individual structures begin to exceed what can be launched, deployed, docked, or inflated and allow true economies of scale to be unlocked in space. However, typical terrestrial methods of forming and shaping sheet metal require massive machinery with the ability to deflect reaction forces to a large mass in a fixed reference frame (Earth). To both limit up-mass required for manufacture and to mitigate the issues of reaction forces in the relative reference frames of space, a non-contact, laser-based method of forming metal sheet is proposed. NASA Marshall Space Flight Center (MSFC), in cooperation with DARPA and the University of Florida (UF), have begun investigation of non-contact methods of laser forming sheet metal in thermal vacuum (TVAC) conditions to great success. To date, several grades of aluminum, stainless steel, and titanium coupons have been formed via laser-induced internal stresses in these metals at both ambient atmosphere and vacuum conditions. Temperatures in these tests ranged from -120 to 60 C, and though the total energy required to induce strain does vary with workpiece temperature and environmental pressure, the method remains predictable and controllable for the materials investigated. It is believed that this method will revolutionize manufacturing in-space as it not only continues to build upon the capabilities of the laser (sensing, marking, cutting, drilling, joining, and now forming) as an all-in-one tool, but also reduces the need to counteract forming forces as would be required in mechanical bending. In theory, all required stress to induce bending is generated through thermal gradient and strain within the workpiece, meaning that the need for reaction control and fuel expense on-orbit will be limited. Archimedes once stated, “Give me a lever long enough and a fulcrum on which to place it, and I shall move the world”. With a laser as our lever and our workpiece its own fulcrum, we can move the world’s manufacturing into space.

Laser↗

DOE OSTI2024

Laser Based Ultrasound for Verification of Circuit Card Assemblies

This IR is a follow-up conference Paper to the IR approved abstract; PNNL-SA-194096. --- Verification that equipment is authentic and not changed; even at the circuit card assembly (CCA) level will likely be an important component of future arms control treaties. This effort was an initial evaluation of the potential for laser-based ultrasound (LBU) as an inspection tool for Unique Identification (UID) of Circuit Card Assembly (CCA) boards and CCA components. The LBU system used a laser pulse for ultrasound generation and an Optical Microphone for ultrasound detection to image subsurface structures without physical contact and in a dry state. This paper described the selected CCA surrogate, CCA components that were examined, the LBU system, LBU images of the CCA components, and the initial development of UID algorithms. Receiver operating characteristics (ROC) curves indicated good performance for two algorithms as a potential means for UID of CCA boards and CCA components.

Laser Ultrasound, Equipment Verification, Arms Con↗

DOE OSTI2024

Laser absorptivity measurement device

A laser absorptivity measurement device uses a linearly polarized incident beam, an optical configuration comprising an internal polarizing beamsplitter that transmits the linearly polarized incident beam and a quarter-wave plate that converts linearly polarized incident beam into a circularly polarized incident beam that is reflected off a processing substrate. The quarter-wave plate and polarizing beamsplitter can then direct the reflected light back into an integrating volume, where the power of the reflected light can be measured by a photodetector. The laser absorptivity measurement device is capable of making real-time absorption efficiency measurements of a variety of laser-based processes, including laser welding and brazing, additive manufacturing, and laser marking.

Tung, Daniel↗

DOE OSTI2024

Experimental investigation of thermal conductivity of high entropy ceramics

In this talk, we will present the experimental investigation of thermal conductivity of high entropy carbides (HEC) and borides (HEB) with different compositions. Thermal conductivity determines the capability of a material to transport thermal energy and is considered as one critical physical property, specially in the energy industry. Due to the presences of disordered cation sublattice, it is expected that thermal conductivity of high entropy ceramics is lower than the counterparts with simpler compositions, but the experimental studies are relatively few. Using laser-based spatial-domain and frequency-domain thermoreflectance technique, we measured thermal conductivity of HECs and HEBs in a temperature range from 77K to 773K. Furthermore, by focusing the laser using an objective lens, we were able to perform the thermal property mapping on samples with the spatial resolution of micrometer. Such measurements could reveal important microstructure information in a rapid and efficient way without using scanning electron microscopy. The high spatial resolution also enables thermal conductivity measurements on ion-irradiated HECs with the damage layer of merely 1.1µm. These measurements can provide valuable information to predict the performances of HECs and HEBs with different compositions and from different manufacturing processes, and in the extreme environments such as nuclear reactors.

36 - MATERIALS SCIENCE↗

DOE OSTI2026

Forensic characterization of surrogate nuclear explosion debris: radiochemical and spectroscopic strategies for method validation

Surrogate nuclear explosion debris (SNED) has emerged as a critical platform for advancing post-detonation nuclear forensic analysis in the absence of readily accessible historic materials. SNED enables controlled investigation and validation of analytical methodologies used to interrogate the chemical, isotopic, radiological, and microstructural signatures preserved in nuclear explosion debris. This review presents an integrated assessment of destructive and non-destructive analytical techniques commonly employed within decision-driven nuclear forensic workflows. Each technique is discussed individually while highlighting how it contributes to different stages of post-detonation analysis. Core methods – including gamma and alpha spectrometry, ICP-MS, TIMS, SIMS, SEM-EDS, XRF, LIBS, vibrational spectroscopy, and X-ray absorption spectroscopy – are critically evaluated with respect to forensic maturity, information content, and matrix limitations. Emphasis is placed on the role of SNED in benchmarking multi-modal workflows and identifying gaps in reproducing heterogeneity, fractionation, and radiation-driven evolution relevant to forensic attribution.

X-ray spectroscopic methods↗