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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 541 records · Page 30
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Hot gas path component cooling system

A cooling system for a hot gas path component is disclosed. The cooling system may include a component layer and a cover layer. The component layer may include a first inner surface and a second outer surface. The second outer surface may define a plurality of channels. The component layer may further define a plurality of passages extending generally between the first inner surface and the second outer surface. Each of the plurality of channels may be fluidly connected to at least one of the plurality of passages. The cover layer may be situated adjacent the second outer surface of the component layer. The plurality of passages may be configured to flow a cooling medium to the plurality of channels and provide impingement cooling to the cover layer. The plurality of channels may be configured to flow cooling medium therethrough, cooling the cover layer.

42 ENGINEERING↗
DOE OSTI2014

Graphene-based battery electrodes having continuous flow paths

Some batteries can exhibit greatly improved performance by utilizing electrodes having randomly arranged graphene nanosheets forming a network of channels defining continuous flow paths through the electrode. The network of channels can provide a diffusion pathway for the liquid electrolyte and/or for reactant gases. Metal-air batteries can benefit from such electrodes. In particular Li-air batteries show extremely high capacities, wherein the network of channels allow oxygen to diffuse through the electrode and mesopores in the electrode can store discharge products.

25 ENERGY STORAGE↗
DOE OSTI2014

Path-sensitive analysis for reducing rollback overheads

A mechanism is provided for path-sensitive analysis for reducing rollback overheads. The mechanism receives, in a compiler, program code to be compiled to form compiled code. The mechanism divides the code into basic blocks. The mechanism then determines a restore register set for each of the one or more basic blocks to form one or more restore register sets. The mechanism then stores the one or more register sets such that responsive to a rollback during execution of the compiled code. A rollback routine identifies a restore register set from the one or more restore register sets and restores registers identified in the identified restore register set.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2015

Systems and methods for managing shared-path instrumentation and irradiation targets in a nuclear reactor

Systems and methods permit discriminate access to nuclear reactors. Systems provide penetration pathways to irradiation target loading and offloading systems, instrumentation systems, and other external systems at desired times, while limiting such access during undesired times. Systems use selection mechanisms that can be strategically positioned for space sharing to connect only desired systems to a reactor. Selection mechanisms include distinct paths, forks, diverters, turntables, and other types of selectors. Management methods with such systems permits use of the nuclear reactor and penetration pathways between different systems and functions, simultaneously and at only distinct desired times. Existing TIP drives and other known instrumentation and plant systems are useable with access management systems and methods, which can be used in any nuclear plant with access restrictions.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2016

Transversely-illuminated high current photoconductive switches with geometry-constrained conductivity path

A photoconductive switch having a wide bandgap semiconductor material substrate between opposing electrodes, with one of the electrodes having an aperture or apertures at an electrode-substrate interface for transversely directing radiation therethrough from a radiation source into a triple junction region of the substrate, so as to geometrically constrain the conductivity path to within the triple junction region.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Thermally determining flow and/or heat load distribution in parallel paths

A method including obtaining calibration data for at least one sub-component in a heat transfer assembly, wherein the calibration data comprises at least one indication of coolant flow rate through the sub-component for a given surface temperature delta of the sub-component and a given heat load into said sub-component, determining a measured heat load into the sub-component, determining a measured surface temperature delta of the sub-component, and determining a coolant flow distribution in a first flow path comprising the sub-component from the calibration data according to the measured heat load and the measured surface temperature delta of the sub-component.

42 ENGINEERING↗
DOE OSTI2017

Gas flow path for a gas turbine engine

A duct arrangement in a can annular gas turbine engine. The gas turbine engine has a gas delivery structure for delivering gases from a plurality of combustors to an annular chamber that extends circumferentially and is oriented concentric to a gas turbine engine longitudinal axis for delivering the gas flow to a first row of blades A gas flow path is formed by the duct arrangement between a respective combustor and the annular chamber for conveying gases from each combustor to the first row of turbine blades The duct arrangement includes at least one straight section having a centerline that is misaligned with a centerline of the combustor.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2017

Thermally determining flow and/or heat load distribution in parallel paths

A method including obtaining calibration data for at least one sub-component in a heat transfer assembly, wherein the calibration data comprises at least one indication of coolant flow rate through the sub-component for a given surface temperature delta of the sub-component and a given heat load into said sub-component, determining a measured heat load into the sub-component, determining a measured surface temperature delta of the sub-component, and determining a coolant flow distribution in a first flow path comprising the sub-component from the calibration data according to the measured heat load and the measured surface temperature delta of the sub-component.

42 ENGINEERING↗
DOE OSTI2018

Hot gas path component cooling system having a particle collection chamber

A cooling system for a hot gas path component includes a substrate having an outer surface and an inner surface. The inner surface defines at least one interior space. A passage is formed in the substrate between the outer surface and the inner surface. An access passage is formed in the substrate and extends from the outer surface to the inner space. The access passage is formed at a first acute angle to the passage and includes a particle collection chamber. The access passage is configured to channel a cooling fluid to the passage. Furthermore, the passage is configured to channel the cooling fluid therethrough to cool the substrate.

42 ENGINEERING↗
DOE OSTI2018

Hot gas path component having cast-in features for near wall cooling

A hot gas path component includes a substrate having an outer surface and an inner surface. The inner surface of the substrate defines at least one interior space. At least a portion of the outer surface of the substrate includes a recess formed therein. The recess includes a bottom surface and a groove extending at least partially along the bottom surface of the recess. A cover is disposed within the recess and covers at least a portion of the groove. The groove is configured to channel a cooling fluid therethrough to cool the cover.

42 ENGINEERING↗
DOE OSTI2018

Estimation of network path segment delays

A method for estimation of a network path segment delay includes determining a scaled time stamp for each packet of a plurality of packets by scaling a time stamp for each respective packet to minimize a difference of at least one of a frequency and a frequency drift between a transport protocol clock of a host and a monitoring point. The time stamp for each packet is provided by the transport protocol clock of the host. A corrected time stamp for each packet is determined by removing from the scaled time stamp for each respective packet, a temporal offset between the transport protocol clock and the monitoring clock by minimizing a temporal delay variation of the plurality of packets traversing a segment between the host and the monitoring point.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2018

Hot gas path component trailing edge having near wall cooling features

A hot gas path component includes a substrate having an outer surface and an inner surface. The inner surface defines an interior space. The outer surface defines a pressure side surface and a suction side surface. The pressure and suction side surfaces are joined together at a leading edge and at a trailing edge. A first cooling passage is formed in the suction side surface of the substrate. It is coupled in flow communication to the interior space. A second cooling passage, separate from the first cooling passage, is formed in the pressure side surface. The second cooling passage is coupled in flow communication to the interior space. A cover is disposed over at least a portion of the first and second cooling passages. The interior space channels a cooling fluid to the first and second cooling passages, which channel the cooling fluid therethrough to remove heat from the component.

42 ENGINEERING↗
DOE OSTI2018

Control System Framework for Using G-Code-Based 3D Printing Paths on a Multi-Degree of Freedom Robotic Arm

This paper describes a control system framework using G-Code-based 3D printing paths on a serial link robot manipulator with multiple degrees of freedom. Usually, G-Code is created by a software application, commonly referred to as a slicer, meant for gantry systems. However, G-Code does not address the kinematic complexity nor take advantage of the flexibility available in serial link robot manipulators. This paper provides an overview of the additive manufacturing process and G-Code, types of additive manufacturing deposition movements, common terminology used, the roles of parsers and translators, step-by-step instructions on how to implement this control system, and results and findings from this research. The presented framework can be used for a number of additive manufacturing methods, hybrid solutions, or applications not directly related to additive manufacturing. The implementation was successfully tested on a manipulator with seven degrees of freedom that successfully performed hundreds of hours of large-scale wire arc metal deposition.

Nycz, Andrzej↗
DOE OSTI2018

A study of fission product migration paths in irradiated TRISO particle SiC

Tristructural isotropic (TRISO) coated fuel particles used in high-temperature gas-cooled nuclear reactors (HTGRs) provide key advantages in terms of passive safety and reactor energy efficiencies. TRISO fuel consists of a number of special coating layers surrounding the fissile material in the kernel as shown in Fig. 1. The coating layers consist of a carbon buffer layer, inner pyrolytic carbon (PyC) layer, a silicon carbide (SiC) layer as well as an outer pyrolytic carbon layer. Together the layers act as a pressure vessel and barrier to the release of radioactive fission products into the reactor environment. The cubic 3C-SiC layer of thickness approximately 35 µm, acts as the primary barrier to the migration of metallic fission products out of the particle. The finding, more than three decades years ago, that silver can be released by intact TRISO particles has led to significant research to determine possible transport mechanisms of certain fission products in SiC. Out-of-reactor experiments did not reveal any significant lattice diffusion of silver in SiC1. Many earlier findings alternatively proposed a dominating role of fast diffusion paths such as grain boundaries and dislocations in enhancing fission product migration in SiC. Recently the role of the fission product palladium in enhancing the transport rate of silver in SiC2 was confirmed by transmission electron microscopy (TEM) of neutron-irradiated SiC from a TRISO coated particle from Compact 4-1-1, which was irradiated to an average burnup of 19.38% fissions per initial metal atom (FIMA); a time-averaged, volume-averaged temperature of 1072 °C; a time-averaged peak temperature of 1182 °C; and an average fast fluence of 4.13 x 1021 n/cm2 as part of the US Department of Energy's Advanced Gas Reactor (AGR)-1 experiment3. Although other studies found that Ag was found separately (without Pd) in TRISO coated particles irradiated at 11.4 %, 16.7 and 18.6% FIMA, Pd could have been present at lower than measureable concentrations4. In this study, SiC focussed ion beam (FIB) sections obtained from Compact 4-1-1 from the AGR-1 experiment were analysed in a double Cs-corrected JEOL ARM 200F using atomically resolved scanning transmission electron microscopy (STEM). By using atom resolved STEM in combination with electron energy loss spectroscopy (EELS) and large angle energy dispersive spectroscopy (EDS) a much better understanding of the migration routes and mechanisms of fission products in irradiated polycrystalline 3C-SiC was achieved.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2019

Impact of High Q on ILC250 Upgrade for Record Luminosities and Path Toward ILC380

In this paper, we address the possibility of upgrading the ILC250 luminosity to $8.1 \times 10^{34}$, so that with the polarization feature, the effective luminosity will be $2.0 \times 10^{35}$ to compete with the FCC-ee luminosity and two detectors. The additional cost of the higher luminosity option will be about 2.2 B ILCU. The total cost for the ILC high luminosity machine will therefore be about 7.7 B versus FCC-ee 10.5 B. The AC power (267 MW) to operate the ILC luminosity upgrade will also be less than the AC power for FCC-ee (300 MW). Even with a modest quality factor Q of $1 \times 10^{10}$ for SRF cavities, the total cost of the upgrade will be 2.5 B ILCU additional over ILC250 baseline. We expect that, if approved, ILC250 will first be built at the baseline luminosity, operated for many years at this luminosity, and later upgraded to the high luminosity option. A significant part (RF power and cryo-power) of the additional cost for the luminosity upgrade overlaps with the expected additional costs for anticipated energy upgrade paths. A second ILC upgrade discussed in this paper will be to the higher energy Top Factory at 380 GeV. We also estimate the additional cost of this upgrade (1.5 B ILCU).

43 PARTICLE ACCELERATORS↗
DOE OSTI2020

Phonon Mean Free Path Spectroscopy: Theory and Experiments

Chapter 6 reviews the current status of resolving the phonon mean free path distribution in real materials from both the computational and experimental perspectives, which is essential for engineering materials at the nanoscale to achieve desirable thermal transport properties.

Hua, Chengyun↗