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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 1,405 records · Page 78
All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

Angled Core Gas Turbine Engine Mounting

A propulsion system for an aircraft includes first and second turbine engines mounted within a fuselage of the aircraft. The first turbine engine includes a first engine core that drives a first propulsor disposed about a first propulsor axis. The second turbine engine includes a second engine core and a second propulsor disposed about a second propulsor axis parallel to the first propulsor axis. The first engine core and the second engine core are mounted at an angle relative to corresponding ones of the first and second propulsor axes.

Suciu, Gabriel L.↗
NASA NTRS2019

Volatile Element Depletion of the Moon – The Roles of Pre-Cursors, Post-Impact Disk Dynamics, and Core Formation

The compositional and isotopic similarity of Earth’s primitive upper mantle (PUM) and the Moon has bolstered the idea that the Moon was derived from the proto-Earth, but the Moon’s inventory of volatile lithophile elements – Na, K, Rb and Cs – are lower than in Earth’s PUM by a factor of 4 to 5. The abundances of fourteen other volatile elements exhibit siderophile behavior (volatile siderophile elements or VSE; P, As, Cu, Ag, Sb, Ga, Ge, Bi, Pb, Zn, Sn, Cd, In, and Tl) that could be used to evaluate whether the Moon was derived from the proto-Earth, and whether their depletion can be attributed to volatility or core formation. In this study, newly available core-mantle partitioning data are used, together with bulk Moon compositions, protolunar disk dynamics modelling to test the hypothesis that the Moon was derived from PUM-like material. At lunar core formation conditions, As, Sb, Ag, Ge, Bi, Sn are siderophile, whereas P, Cu, Ga, Pb, Zn, Cd, In and Tl are all weakly siderophile or lithophile. Most of the VSE can be explained by a combination of known processes – pre-cursor volatile depletion, melt-gas dynamics and equilibria in the protolunar disk, and core formation. Explaining this whole group of volatile elements may require a combination of mixing and separation of the newly formed Moon from remnant gas rich in the highest volatility VSEs. This large group of volatile elements informs a wide temperature range and offers a powerful test of melt-gas segregation mechanisms in the protolunar disk and lunar formation hypotheses.

Righter, K.↗
NASA NTRS2019

Reassessment of Electromagnetic Core-Mantle Coupling and Its Implications to the Earth's Decadal Polar Motion

The observed Earth's polar motion on decadal time scales has long been conjectured to be excited by the exchange of equatorial angular momentum between the solid mantle and the fluid outer core, via the mechanism of electromagnetic (EM) core-mantle coupling. However, past estimations of the EM coupling torque from surface geomagnetic observations is too weak to account for the observed decadal polar motion. Our recent estimations from numerical geodynamo simulations have shown the opposite. In this paper, we re-examine in detail the EM coupling mechanism and the properties of the magnetic field in the electrically conducting lower mantle (characterized by a thin D″-layer at the base of the mantle). Our simulations find that the toroidal field in the D″-layer from the induction and convection of the toroidal field in the outer core could be potentially much stronger than that from the advection of the poloidal field in the outer core. The former, however, cannot be inferred from geomagnetic observations at the Earth's surface, and is missing in previous EM torque estimated from geomagnetic observations. Our deduction suggests further that this field could make the actual EM coupling torque sufficiently strong, at approximately 5 × 10(exp 19) Nm, to excite, and hence explain, the decadal polar motion to magnitude of approximately 10 mas.

Kuang, Weijia↗
NASA NTRS2020

Core Losses in Co-Rich Inductors with Tunable Permeability

High frequency, low loss power systems enable electrified aircraft propulsion. Filter inductors that reduce noise in high current systems can account for 50% of the motor drive mass. Efficient inductor cores with tunable permeability reduce system mass by producing less heat, that removes heat sink mass. Requirements for filter inductors vary based on the chosen topology, but all inductor cores must operate below saturation levels. As the saturation flux density is limited (less than ~2 T), high differential current applications require cores with low relative permeabilities. The large induced anisotropies possible in Co-rich metal amorphous nanocomposite materials enables gapless inductors with relative permeabilities down to ~20. These materials have fine grain size ~8nm with a faulted, close packed structure. The impact of different processing methods on core losses are presented along with comparison to other low permeability soft magnetic materials.

Leary, Alex↗
NASA NTRS2020

Polarimetric Radar Characteristics of Simulated and Observed Intense Convective Cores for a Midlatitude Continental and Tropical Maritime Environment

This study contrasts midlatitude continental and tropical maritime deep convective cores using polarimetric radar observables and retrievals from selected deep convection episodes during the MC3E and TWPICE field campaigns. The continental convective cores produce stronger radar reflectivities throughout the profiles, while maritime convective cores produce more positive differential reflectivity Z(dr) and larger specific differential phase K(dp) above the melting level. Hydrometeor identification retrievals revealed the presence of large fractions of rimed ice particles (snow aggregates) in the continental (maritime) convective cores, consistent with the Z(dr) and K(dp) observations. The regional cloud-resolving model simulations with bulk and size-resolved bin microphysics are conducted for the selected cases, and the simulation outputs are converted into polarimetric radar signals and retrievals identical to the observational composites. Both the bulk and the bin microphysics reproduce realistic land and ocean (L-O) contrasts in reflectivity, polarimetric variables of rain drops, and hydrometeor profiles, but there are still large uncertainties in describing Zdr and Kdp of ice crystals associated with the ice particle shapes/orientation assumptions. Sensitivity experiments are conducted by swapping background aerosols between the continental and maritime environments, revealing that background aerosols play a role in shaping the distinct L-O contrasts in radar reflectivity associated with raindrop sizes, in addition to the dominant role of background thermodynamics.

Toshihisa Matsui↗
NASA NTRSDate not supplied

From Apollo to Artemis: Opening and Processing Lunar Core 73002 for the ANGSA Program

The Apollo mission returned 382 kg of lunar material comprising rock, soil and core samples. Some of these samples were intentionally set aside after their return from the Moon for future study, including samples sealed on the lunar surface, frozen samples and samples stored under Helium. The Apollo Next Generation Sample Analysis (ANGSA) program was established to study thesesamples, in part to help bridge the gap between Apollo and the next generation of lunar science and exploration.Apollo 17 double drive tube core sample 73001/73002 was collected about 50 meters east of Lara Crater from a landslide deposit originating from South Massif. After separating the two halves, the lower drive tube 73001 was immediately sealed in a special vacuum container. Both drive tubes were then placed in an Apollo Lunar Sample Return Container (ALSRC) and returned to Earth under vacuum. Total sample weight and length of 73001/73002 is 1263.0 g and up to 60 cm, with the upper drive 73002 containing 429.7 g and 23 cm of material ( which was then compressed to 18.5 cm during extrusion in the lab). We will present the meticulous methods involved in preparing for, opening and processing lunar core 73002, the upper half of the double drive tube. This includes searching and locating procedures and tools, practicing assembly and extrusion in a mock-up, and finally opening and dissecting the core sample 73002. Challenges (both expected and unexpected) encountered along the way and lessons learned during this project will help pave the way towards improving future lunar sample return missions and advancing insight into the Moon’s history

C. H. Krysher↗
NASA NTRS2020

Design and Development of a Robust Chuck Mechanism for the Mars2020 Coring Drill

The Sampling and Caching Subsystem (SCS) onboard the Mars2020 rover includes a coring drill that can perform coring, abrasion, and regolith collection operations. The coring drill requires a chuck mechanism to allow for the changing of the bits needed to perform sampling. The chuck mechanism must be capable of securely connecting a bit under drilling, rover slip, and pullout loads, but also readily release a bit after application of these loads. The Mars2020 chuck consists of a ball lock mechanism that allows for robust engagement and release of bit assemblies that is preloaded to ensure a secure, stiff connection between the bit assembly and the rest of the corer. To prevent jamming, the chuck incorporates rollers to preload the ball lock. The rollers are mounted onto a flexured cam that minimizes changes in internal mechanism loads that result from thermally induced dimensional changes, further mitigating the potential for jamming. The chuck mechanism is moved between engaged, disengaged, and loose chuck positions by rotating the cam with a gearmotor that incorporates a magnetic detent brake that prevents inadvertent mechanism motion under design loads. Ongoing testing is occurring on the qualification model in a dirty environment while coring and abrading rocks in a Mars representative environment.

Barletta, Anthony↗
NASA NTRSDate not supplied

Advanced Materials Development under NASA’s Hybrid Thermally Efficient Core (HyTEC) Project

The Hybrid Thermally Efficient Core (HyTEC) project aims to develop small core turbofan engine technologies that will enable fuel burn reductions, additional use of electric airplane systems through power extraction, and to advance engine operability and compatibility with sustainable aviation fuels. As such, a portfolio of technologies that contribute to raising the pressure, temperature and efficiency of turbofan engine cores needs developed. Included in HyTEC’s technology portfolio to enable these advancements are enhanced combustor liner materials and higher temperature capable turbine blades and vanes manufactured using ceramic matrix composites (CMCs) and environmental barrier coatings (EBCs). These technologies are being developed and tested in laboratory-scale relevant environments to advance the technology readiness level (TRL) to 4 or 5, before moving into an engine core demonstrator to raise the TRL to 6. A new natural gas/oxygen burner rig facility will be used to simulate turbine engine relevant environments at the laboratory/coupon scale. In addition, improvements to enable sub-element, and more complex component testing in NASA Glenn’s combustor facility (CE-5) will be presented.

Ceramic Matrix Composites (CMCs)↗
NASA NTRSDate not supplied

Space Launch System Core Stage Green Run Base Heating: Anomaly, Mitigation and Flight Redesign

The NASA Space Launch System (SLS) vehicle is composed of four RS-25 liquid oxygen and hydrogen rocket engines in the Core Stage (CS). The SLS Core Stage went through Green Run hot-fire testing at NASA Stennis Space Center’s B-2 test facility in 2021. The main goal of this testing was to confirm Core Stage tanking, propulsion and thrust vector control systems operations and performance to verify with predicted models. Two hot-fire (HF) test sequences were performed with the first one (HF1) in January for a test duration of 70 seconds and the second (HF2) testing completed in March for a test duration of 500 seconds. This paper focuses on the base heating anomalies observed during HF1 and HF2 where an extensive fire was observed along the Core Stage base heat shield during test operations. This environment was not anticipated and led to extensive unplanned damage to the thermal protection system which was augmented for flight. Green Run observations also led to a reassessment of flight environments for Artemis I. This paper discusses the potential cause of the anomalies, the flow physics, the reconstructed base environments, and mitigation plans for HF2 and flight.

aerothermodynamics↗
NASA NTRSDate not supplied

Space Launch System Core Stage Green Run Base Heating: Anomaly, Mitigation and Flight Redesign

The NASA Space Launch System (SLS) vehicle is composed of four RS-25 liquid oxygen and hydrogen rocket engines in the Core Stage (CS). The SLS Core Stage went through Green Run hotfire testing at NASA Stennis Space Center’s B-2 test facility in 2021. The main goal of this testing was to confirm Core Stage tanking, propulsion and thrust vector control systems operations and performance to verify with predicted models. Two hot-fire (HF) test sequences were performed with the first one (HF1) in January for a test duration of 70 seconds and the second (HF2) testing completed in March for a test duration of 500 seconds. This paper focuses on the base heating anomalies observed during HF1 and HF2 where an extensive fire was observed along the Core Stage base heat shield during test operations. This environment was not anticipated and led to extensive unplanned damage to the thermal protection system which was augmented for flight. Green Run observations also led to a reassessment of flight environments for Artemis I. This paper discusses the potential cause of the anomalies, the flow physics, the reconstructed base environments, and mitigation plans for HF2 and flight.

aerothermodynamics↗
NASA NTRS2014

ERA Advanced Core Compressor Technology Program

As part of the NASA Integrated Systems Research Program, Environmentally Responsible Aviation Project, NASA GRC and GE Aviation have partnered to investigate the technology barriers associated with improved fuel economy of large gas turbine engines. Crucial to improving fuel economy is the increase in Pressure Ratio (PR) of the core compressor. General Electric is in the process of defining new advanced technology engine concepts and related engine architectures for both commercial and military subsonic and supersonic flight applications. These new concepts and architectures offer the potential of providing substantial improvements in mission fuel burn, emissions, and noise levels relative to SOTA engines and support the needs and goals of future Air force, Navy, and NASA aircraft systems. A key aspect of many of these new engine concepts is an ultra high pressure ratio core compressor. Current SOTA engines such as the GENx utilize a 23:1 class pressure ratio core compressor to achieve an overall pressure ratio in the 50:1 class. Future engines with overall pressure ratios in the 70– 80:1 class will need core compressors with pressure ratios in the 30:1 class. These single spool, ultra high pressure ratio compressors will have inherent challenges. The goal of this work is to provide a dedicated component test vehicle to study the very challenging compressor front stage performance and operability issues that arise in these aggressive machines. With a view to providing highly detailed aerodynamic data that will provide, subject to the rights restrictions for test data afforded under NASA Contract NNC10BA06B/NNC10TA64T, an industry standard data set for CFD validation.

Axial Compressors↗
DOE OSTI2015

Scalable Out-of-Core Solvers on Xeon Phi Cluster

This paper documents the implementation of a distributive out-of-core (OOC) solver for performing LU and Cholesky factorizations of a large dense matrix on clusters of many-core programmable co-processors. The out-of- core algorithm combines both the left-looking and right-looking schemes aimed to minimize the movement of data between the CPU host and the co-processor, optimizing data locality as well as computing throughput. The OOC solver is built to align with the format of the ScaLAPACK software library, making it readily portable to any existing codes using ScaLAPACK. A runtime analysis conducted on Beacon (an Intel Xeon plus Intel Xeon Phi cluster which composed of 48 nodes of multi-core CPU and MIC) at the Na- tional Institute for Computational Sciences is presented. Comparison of the performance on the Intel Xeon Phi and GPU clusters are also provided.

D'Azevedo, Ed F↗
DOE OSTI2014

Turbulent Heating of the Core Solar Wind Protons in the Outer Heliosphere

A model of the interstellar pickup protons, slab component of the Alfvénic turbulence, and core solar wind (SW) protons is presented for r ≥ 1 AU along with a comparison with the Voyager 2 (V2) observations of the core SW temperature. The main conclusions of our study are summarized as follows. (1) A combined effect of the Wentzel-Kramers-Brillouin attenuation, large-scale driving, and pickup proton generated waves results in the turbulent energy sink in the region 1 AU < r < 10 AU, while energy is pumped in the turbulence beyond ˜ 10 AU. Without energy pumping the nonlinear energy cascade is suppressed for r < 10 AU. A similar situation takes place for the 2D turbulence. (2) For both the slab and 2D turbulent components at the heliocentric distances r < 10 AU, the energy source for the core SW protons due to the Alfvén wave dissipation is small. As a result, adiabatic cooling mostly controls the model SW temperature in this region, and the model temperature disagrees with the V2 observations in the region r < 20 AU. (3) The model core SW temperature agrees well with the V2 observations for r > 20 AU.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2018

Using Stage Level Microseismic Analysis to Investigate Correlate and Ground Truth Cored Hydraulic Fractures

The Hydraulic Fracture Test Site in Reagan County, Texas contains a valuable dataset to correlate the occurrence, position and frequency of microseismic events in relation to physical observations of hydraulic fractures taken from a low-angle whole core acquired immediately adjacent and subsequent to a modern hydraulically fractured horizontal well within the Upper & Middle Wolfcamp formations. Microseismic event density maps visualized through time locate concentrations of microseismic activity in relation to independently documented hydraulic and naturally occurring fractures. Microseismic activity observed over the duration of a single completion stage at the closest proximity to the cored interval demonstrates conformity and correlation with the presence of hydraulic fractures. Changes in microseismic signature are also correlated with changes in pump rates and pressures throughout treatment. A positive correlation was found between the high certainty hydraulic fractures observed in the core and areas of highest microseismic density in the stage of the neighboring horizontal nearest to the Upper Wolfcamp cored interval of the slant well, demonstrating that microseismic density can be a reliable indicator of hydraulic fracture density and complexity around the stimulated well. Given caveats often cited with microseismic acquisition, processing and interpretation, this study provides a ground truth example and insights into the degree of accuracy microseismic can offer as a technology in discerning the efficacy of modern completions.

Fairfield, Ryan↗
DOE OSTI2018

Conformal core cooling and containment structure

A nuclear reactor includes a pressure vessel and a nuclear reactor core comprising fissile material disposed inside the pressure vessel at the bottom of the pressure vessel. A secondary core containment structure includes a containment basket comprising insulation with a maximum stable temperature of at least 2200K cladded by steel. The bottom of the pressure vessel and the nuclear reactor core are disposed inside the containment basket with the containment basket spaced apart from the bottom of the pressure vessel by a clearance gap. The containment basket may comprise zirconia insulation cladded by steel. In some embodiments the clearance gap between the containment basket and the bottom of the pressure vessel is no larger than one meter. The secondary core containment structure may further comprise conduits arranged to inject water into the clearance gap between the containment basket and the bottom of the pressure vessel.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2018

Conformal core cooling and containment structure

A nuclear reactor includes a pressure vessel and a nuclear reactor core comprising fissile material disposed inside the pressure vessel at the bottom of the pressure vessel. A secondary core containment structure includes a containment basket comprising insulation with a maximum stable temperature of at least 2200K cladded by steel. The bottom of the pressure vessel and the nuclear reactor core are disposed inside the containment basket with the containment basket spaced apart from the bottom of the pressure vessel by a clearance gap. The containment basket may comprise zirconia insulation cladded by steel. In some embodiments the clearance gap between the containment basket and the bottom of the pressure vessel is no larger than one meter. The secondary core containment structure may further comprise conduits arranged to inject water into the clearance gap between the containment basket and the bottom of the pressure vessel.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2019

Core structured components and containers

A structural component with at least two side members has a support structure that includes a partition with multiple curved portions forming cells. The partition connects to the side members and extends between the side members at least partially along straight lines. The partition may extend along one or more straight lines from one side member to the other. One structural component is a container with a wall about the internal support structure. The container cells may be formed with a core structure. The core can include a permeable storage material and may be retained after formation, or may be removed. In some cases the container wall has generally planar surfaces, which may include surface undulations. Core structures are also provided for forming structural components. Formation can include casting a material about a core structure within a mold to form a partition extending between two or more sides.

Loukus, Adam R.↗
DOE OSTI2019

Collective memory transfer devices and methods for multiple-core processors

This disclosure provides systems, methods, and apparatus for collective memory transfers. A control unit may be configured to coordinate a transfer of data between a memory and processor cores. For a read data transfer operation, the control unit may receive a trigger packet identifying a read data transfer operation and identifying a first plurality of data lines based on data values included in the trigger packet. The control unit may read the first plurality of data lines from the memory sequentially and send a second plurality of data lines to the processor cores. For a write data transfer operation, the control unit may send a request for at least one data line to a plurality of processor cores, may receive and reorder the requested data lines, and may write the data lines to a memory. The control unit may determine a mapping between processor cores and the memory.

97 MATHEMATICS AND COMPUTING↗