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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

NGC 4869 in the Coma Cluster: Twist, Wrap, Overlap, and Bend

The upgraded Giant Metrewave Radio Telescope (GMRT) has been used to image the head–tail radio galaxy NGC 4869 in the Coma cluster with an angular resolution of 6.″26 at 250–500 MHz and 2.″18 at the 1050–1450 MHz bands. The archival legacy GMRT data have also been used to image the source with angular resolutions from 4.″9 to 21.″8 at 610 MHz, 325 MHz, 240 MHz, and 150 MHz. We find that the ∼200 kpc scale radio morphology consists of five distinct regions with the clear presence of a pinch at ≈1.′4 (=38.8 kpc) and a ridge at ≈3.′4 (=94.2 kpc) from the head. The sharp bend by ∼70° at ∼3.′5 (=97 kpc) from the head is possibly due to projection effects. The radio spectra show progressive spectral steepening as a function of distance from the head and there is possibly re-acceleration of the synchrotron electrons and perhaps also magnetic field regeneration in the 6″–208″ (=2.8–96.1 kpc) region of the jet. We report a steep spectrum sheath layer enveloping a flat spectrum spine, hinting at a transverse velocity structure with a fast-moving spine surrounded by a slow-moving sheath layer. We also derive the lifetimes of the radiating electrons and equipartition parameters. A plausible explanation for the characteristic feature, a ridge of emission perpendicular to the direction of tail is the flaring of a straight, collimated radio jet as it crosses a surface brightness edge due to Kelvin–Helmholtz instabilities.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

Combined shipping protection and impingement detection wrap

A packaging material comprised of a gas-impermeable base layer, an indicator layer, and a gas-impermeable top layer is disclosed. The top layer is selected to rupture upon experiencing an impingement or impact that exceeds a predetermined threshold. The indicator layer is configured to change visual appearance upon exposure to ambient air. The top layer further may be configured into a plurality of cells, with each cell filled with a gas that is inert with respect to the indicator layer. The cells may be of a size and shape configured to indicate the location and shape of an impingement or impact, to alert a recipient of an item protected by the packaging material of an area that may require further inspection.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Full Length Assembly Testing in PELICAN (Final Report)

In support of the development of the U.S. Department of Energy (DOE) Versatile Test Reactor (VTR), a thermal hydraulics test facility was constructed to generate experimental measurement of the pressure drop across a single full-scale assembly containing prototypic axial reflectors, fuel, and plena components. Constructed and operated at Argonne National Laboratory, the Pressure drop Experimental Loop for Investigations of Core Assemblies in Nuclear reactors (PELICAN) facility was designed to achieve hydraulic conditions identical to those anticipated for a full-scale fuel assembly located in the VTR core in the region with the highest flow rate. Using water as surrogate for liquid sodium, the flow loop was operated at elevated temperatures and pressures to match the thermophysical properties of liquid sodium and ensure matching Reynolds and Euler numbers. The measurement objectives for data generated from this test facility was driven primarily by the validation needs for code calculations and simulations of the reference VTR core. These objectives focused on the need to validate pressure drop results across the various segments of the fuel assembly as they relate directly to the pumping power and safety of the reactor. Presented in this report are experimental results and analytical comparisons based on testing of a full-length assembly in PELICAN. Housed within a hexagonal test section extending 3.4 m in length, the tested assembly features a prototypic lower reflector, grid plates, wire-wrapped rod bundle, upper reflector, and exit region. The rod bundle extends over 1.5 m in length and contains 217 individual wire-wrapped rods with dimensions that best reflect the reference VTR design. The as-tested bundle assembly was fabricated using 316 stainless steel 0.25-inch (6.35-mm) diameter rods wrapped with 0.04-inch (1.016-mm) diameter wire at a helical pitch of 10.51 inch (26.6 cm). Details of the method for in-house wire-wrapping, assembly, and installation are provided later in this report. Experimental measurements of pressure drop at 19 positions along the test assembly were recorded for a range of flow conditions, with special attention paid to key locations within the assembly, including component inlet and outlet, transition, and wire-wrapped rod bundle regions. Testing conditions were based on 110°C water with flow rates ranging from 50 to 450 GPM (3 to 27 kg/s) at the inlet of the test assembly generating Reynolds numbers and velocities up to ~8.0×10 4 and ~7.8 m/s, respectively, within the rod bundle region. Non-dimensional values for the friction factor were then calculated based on these experimental measurements and compared against those predicted by various analytical correlations available from open literature. Predictions by the upgraded Cheng and Todreas, Rehme, and Novendstern correlations fell within 4% to those values measured experimentally.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2021

Process for manufacturing SiC composite ceramics

A method is described for manufacturing a ceramic composite structure. The method includes wrapping ceramic fibers (22), such as SiC fibers, about the external surface of at least one form. The method further includes heating the wrapped fibers (22) to a temperature no greater than a first temperature, infiltrating voids (24) in the wrapped fibers (22) with the ceramic composite in a first vessel (12) at the first temperature, transferring the infiltrated wrapped fibers (22) from the first vessel (12) to a second vessel (14), distinct from the first vessel (12), and coating the infiltrated wrapped fibers (22) with the ceramic composite in the second vessel (14) at a second temperature, higher than the first temperature.

Lahoda, Edward J.↗
DOE OSTI2026

Mechanical Solution for Existing Conductors

The rapid growth in energy demand, driven by advancements in AI technology, renewable energy integration, and increased industrial activity, highlights the need for innovative solutions to improve the resiliency and efficiency of the power grid. This report details the fire testing of GridWrap’s Composite WiRe Wrap, to evaluate the wrap's ability to enhance conductor performance under wildfire-simulated conditions. Conductors were prepared and tested in a controlled environment at 400°C for 18 minutes, during which sag and temperature data were recorded. The results demonstrated that the unwrapped conductor sagged 3/16ths of an inch, while the WiRe Wrapped conductor sagged only 1/16th of an inch under identical conditions, indicating a significant improvement in mechanical performance. This project, conducted as part of a collaborative effort between BEA (Idaho National Laboratory’s managing contractor) and GridWrap, Inc., demonstrates the potential of grid-enhancing technologies like WiRe Wrap to reduce sag, increase grid resiliency, and support the future energy landscape. By validating the performance of such technologies in real-world scenarios, this work provides critical insights for industry adoption, benefiting both grid operators and U.S. taxpayers through improved reliability, reduced emissions, and enhanced energy delivery.

24 - POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2022

Depletion-Driven Assembly of Polymer-Coated Nanocrystals

Depletion-driven assembly has been widely studied for micron-sized colloids, but questions remain at the nanoscale where the governing physics are impacted by stabilizing surface ligands or wrapping polymers, whose dimensions are similar to those of the colloidal core and the depletant. Here, we probe how wrapping colloidal tin-doped indium oxide nanocrystals with polymers affects their depletion-induced interactions and assembly in solutions of polyethylene glycol. Copolymers of polyacrylic acid grafted with polyethylene oxide provide nanocrystal wrappings with different effective polymer graft densities and molecular weights. (Ultra) small angle X-ray scattering, coarse-grained molecular dynamics simulation, and molecular thermodynamic theory were combined to analyze how depletant size and polymer wrapping characteristics affect depletion interactions, structure, and phase behavior. The results show how depletant molecular weight, as well as surface density and molecular weight of polymer grafts, set thresholds for assembly. These signatures are unique to depletion-driven assembly of nanoscale colloids and mirror phase behaviors of grafted nanoparticle–polymer composites. Optical and rheological responses of depletion-driven assemblies of nanocrystals with different polymer shell architectures were probed to learn how their structural differences impact properties. Finally, we discuss how these wrinkles for depletion-driven assembly at the nanoscale may provide fresh opportunities for designing responsive depletion interactions and dynamically reconfigurable materials.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Test beam study of SiPM-on-tile configurations

Light yield and spatial uniformity for a large variety of configurations of scintillator tiles were studied. The light from each scintillator was collected by a Silicon Photomultiplier (SiPM) directly viewing the produced scintillation light (SiPM-on-tile technique). The varied parameters included tile transverse size, tile thickness, tile wrapping material, scintillator composition, and SiPM model. Furthermore, these studies were performed using 120 GeV protons at the Fermilab Test Beam Facility. External tracking allowed the position of each proton penetrating a tile to be measured. The results were compared to a GEANT4 simulation of each configuration of scinitillator, wrapping, and SiPM.

47 OTHER INSTRUMENTATION↗
DOE OSTI2026

Super Conducting REBCO Cable Wrapper

Future upgrades to CERN particle accelerator magnets require flat, high-temperature superconducting cables, created by wrapping brittle REBCO tape around a Rutherford copper core. Because current manual wrapping processes are time-consuming and prone to damaging the delicate ceramic tape, our team was tasked with automating the fabrication. We developed a modular, wrapping machine featuring adjustment for repeatable 10°to 45° wrap angles and a precise magnetic tensioning mechanism. While full-scale testing is pending final machined parts, our 3D-printed prototype successfully validates the system’s motion and sets the stage for future testing.

Gillen, Kameron [Northern Illinois U.]↗
DOE OSTI2021

Parametric Studies of Heat Pump Water Heater Using Low GWP Refrigerants

A storage heat pump water heater (HPWH) comprises a vapor compression system and a hot water tank. It can lead to more than 70% energy saving, compared with electric resistance heating. HPWH usually uses a wrapped-tank coil as the water heater. The wrapped coil has a strong interaction with the water tank and impose a new challenge for the engineering design and simulation study. Based on the US DOE/ORNL Heat Pump Design Model (HPDM), i.e., a public-domain, component-based thermal system modelling platform, a segment-to-segment wrapped-tank coil model coupled with a one-dimensional stratified water tank model were developed, which facilitates modeling and design HPWHs having various configurations and components. Additionally, the hardware-based design model was used to evaluate refrigerants having lower global warming potentials to replace R-134a, including R-1234yf, R-1234ze, R-290, R-513A and R-450A, when effects of compressor size, refrigerant charge on 24-hour uniform energy factor (UEF) and first-hour rating (FHR) were investigated.In the drop-in replacements, R-1234ze achieved the best UEF, and R-290 resulted in the lowest UEF. When downsizing the compressor to maximize the UEFs, the UEFs of R-134a, R-290, R1234yf, R-450A and R-513A ascended to the range of 4.4 to 4.53, with R-513A having the highest UEF. The R-1234ze ended up having the lowest UEF of 4.27. Refrigerants having larger volumetric vaporization heat led to higher FHRs if using the fixed-size compressor, that R-290 resulted in the highest FHR.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2021

Gauge R & R studies for angular measurements

Angular measurements lie on the circumference of a circle and have different characteristics than standard scalar measurements. For applications involving angular data, treating the measured values as scalars can lead to misinterpretation of results if its wrap-around nature is not taken into account. In this article, we propose a variance components wrapped normal model for angular measurements that is analogous to the standard normal model for continuous measurements. This model allows decomposition of contributions to the overall variance to be separated and compared to understand the drivers of the spread of the data. In this work, we analyze gauge R & R study data using Bayesian methods and illustrate the use of this wrapped normal model with simulated and real data. We also performed a small simulation study in considering the design of gauge R & R studies with angular measurements.

42 ENGINEERING↗