Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “design pattern”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,009 records · Page 56
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Light Material Interactions in Energy Conversion (Final Report)

The scientific vision of the “Light-Material Interactions in Energy Conversion” Energy Frontier Research Center (LMI-EFRC) is embodied in our mission statement: ‘to tailor the morphology, complex dielectric structure, and electronic properties of matter so as to sculpt the flow of sunlight and heat, enabling light conversion to electrical energy with unprecedented efficiency’. Founded in 2009, the LMI-EFRC has become a national resource for fundamental optical principles and phenomena relevant to solar energy conversion, addressing new scientific opportunities that enable efficient utilization of the entire visible and infrared solar resource. The LMI-EFRC is directed by Prof. Ralph Nuzzo and centered at its lead institution, the California Institute of Technology. The Center is an integrated and collaborative partnership of research leaders in photonics and photonic materials, comprising 14 faculty investigators that span six academic departments at five institutions, including Profs. Harry Atwater, Andrei Faraon, Nathan Lewis, and Austin Minnich at Caltech; Profs. Ralph Nuzzo, Paul Braun and John Rogers at the University of Illinois at Urbana-Champaign; Prof. Jennifer Lewis at Harvard University; Profs. Mark Brongersma, Jennifer Dionne, and Shanhui Fan at Stanford University; and Profs. Paul Alivisatos, Eli Yablonovitch, and Xiang Zhang at Lawrence Berkeley National Laboratory. The Center is organized into four research groups (RGs) that address scientific themes related to light-matter interactions, with each team spanning multiple institutional partners and designed to meet our scientific objectives. Notable project outcomes that address the LMI Mission and 2014-2018 goals include: (1) RG1 “New Light Management Mechanisms” demonstrated tunable and active nanostructured patterned surfaces (‘metasurfaces’) for control of light absorption, reflection, and propagation. (2) RG2 “Solar Spectrum Control and Conversion” developed colloidal nanocrystals with designer optical properties for fundamental studies of solar spectrum control and conversion. (3) RG3 “Thermal Photon Harvesting” established photonic design principles to harness and control thermal photons in novel conversion systems. (4) RG4 “Programmable Assembly of Photonic and Electronic Architectures” developed powerful new methods for light- and matter-based additive fabrication of electronic and photonic architectures.

14 SOLAR ENERGY↗
NASA NTRS2019

Swirl Distortion Using Stream Vanes for Boundary Layer Ingestion Research

The swirl distortion of a StreamVane (Trademark) was investigated in the NASA Glenn Research Center W8 test facility. The StreamVane (Trademark) was designed and generated by Virginia Tech based on CFD simulations and included a center body at the aerodynamic interface plane. The swirl pattern generated by the distortion was evaluated using a dense grid of 5-hole Pitot probe measurements captured using a rotating array of probes. Good agreement was found between the design intent and the results at 38.5 kg/s mass flow. The StreamVane (Trademark) swirl results were compared to clean facility flow at 5 inlet mass flows and found to be consistent. Additionally, the axial location of the StreamVane (Trademark) relative to the measurement plane was investigated to determine the impact on downstream total pressure loss generated by the vanes. The intent of this work was to assess the viability of using a StreamVane (Trademark) to generate a Type I or Type II distortion into a Boundary Layer Ingesting propulsor to assess its aerodynamic performance and aeromechanic response.

swirl distortion↗
DOE OSTI2024

Design and optimization of flexible decoupled high-temperature gas-cooled reactor plants with thermal energy storage

Advanced nuclear power plants are well-positioned for future zero-carbon grids, however, the need for flexible power generation will be required over the traditional emphasis on baseload generation for meeting historical demands. To achieve such flexibility, this work examines viable configurations for coupling nuclear energy production with thermal energy storage. Previous designs on nuclear-thermal energy storage configurations for advanced reactor designs, which utilized reactor steam as the heat source for charging the thermal energy storage, are restricted by the heat diversion ratio and efficiency losses, thus their impacts can be limited. In this context, this study proposes configurations for fully decoupling the nuclear reactor from the power cycle and positioning the storage as an intermediate loop, thereby achieving an unconstrained heat diversion ratio and improved efficiency. Compared with a standard high-temperature gas-cooled reactor’s power cycle, steady-state thermodynamic modeling and dispatch optimizations quantify the benefits of a steam reheat cycle within the fully decoupled thermal energy system to separate the plant cycle from the high-pressure primary side. These benefits are further detailed, compatible with required high-temperature and high-pressure conditions, through (1) open-source dynamic transient models that examine the impact of off-design operation on the systems, (2) the investigation of components design and costing and finally (3) sizing and dispatch optimization. The fully-decoupled design achieves a cycle efficiency of 43.1%, an enhancement over the vendor’s standard efficiency of 42.2% (Xe-100 design). Here, the proposed design offers strengthened physical barriers from the nuclear island as well as superior operational flexibility and power boosting. Dispatch optimization and market analysis reveal that thermal energy storage size is highly dependent on the peak patterns of electricity prices and the minimum generation level constraint imposed on the balance of plant. Evaluation of off-design operation demonstrates that the full decoupling design with the suggested fail-safe control mechanisms ensures a minimal impact on reactor parameters, even during rapid power ramping.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2021

Micromachined ceramic-based chipless LC resonator for high-temperature wireless sensing applications in harsh environments

The primary objective of this work was the fabrication and testing of a wireless LC resonator based on micro-patterned electroceramic materials for the monitoring of high-temperature systems. The twodimensional planar LC resonator sensors were designed and simulated using ANSYS Maxwell software, and these sensors were then fabricated from electrically conductive La 2 NiO 4 /Al 2 O 3 particulate inks. Initially, the phases of La 2 NiO 4 /Al 2 O 3 composite were evaluated by XRD. The patterning and deposition of the ink were completed using a novel micro-casting process onto Al 2 O 3 ceramic substrates, and the final pattern was bonded onto the substrate at 1200 °C for 2 h. The features and the reliability were analyzed by SEM microscopy. The frequency shift with respect to temperature was measured, which is directly related to changes in the sensor’s dielectric permittivity and pattern dimensions. The sensors were characterized at 500 °C–1000 °C in an ambient atmosphere with an RF signal ranging from 10–80 MHz at 175 kHz·s –1 sweep rate. The sensors showed a sensitivity of ~350 kHz °C –1 from 500 °C–1000 °C. Here, a new robust and adaptive signal processing approach was introduced to increase the degree of freedom for analyzing wireless sensors.

42 ENGINEERING↗
NASA NTRS1992

Design of a monopulse SAR system to determine elevation angles

Terrain height variations in mountainous areas cause problems in radiometric corrections of synthetic aperture radar (SAR) images. To determine the elevation angle and the height at the different parts of an image, an application of the monopulse principle is proposed. From the ratios of images radiometrically modulated by the difference and sum antenna pattern in range it is possible to calculate the appropriate elevation angle at any point in the image. Design considerations for a corresponding airborne SAR-system are presented, and some estimates of error influences (e.g., ambiguities), expected performance and precision in topographic mapping are given.

Oettl, H.↗
DOE OSTI2016

Introduction of a novel ultrahigh sensitivity collimator for brain SPECT imaging

Purpose: Noise levels of brain SPECT images are highest in central regions, due to preferential attenuation of photons emitted from deep structures. To address this problem, the authors have designed a novel collimator for brain SPECT imaging that yields greatly increased sensitivity near the center of the brain without loss of resolution. This hybrid collimator consisted of ultrashort cone-beam holes in the central regions and slant-holes in the periphery (USCB). We evaluated this collimator for quantitative brain imaging tasks. Methods: Owing to the uniqueness of the USCB collimation, the hole pattern required substantial variations in collimator parameters. To utilize the lead-casting technique, the authors designed two supporting plates to position about 37 000 hexagonal, slightly tapered pins. The holes in the supporting plates were modeled to yield the desired focal length, hole length, and septal thickness. To determine the properties of the manufactured collimator and to compute the system matrix, the authors prepared an array of point sources that covered the entire detector area. Each point source contained 32 μCi of Tc-99m at the first scan time. The array was imaged for 5 min at each of the 64 shifted locations to yield a 2-mm sampling distance, and hole parameters were calculated. The sensitivity was also measured using a point source placed along the central ray at several distances from the collimator face. High-count projection data from a five-compartment brain phantom were acquired with the three collimators on a dual-head SPECT/CT system. The authors calculated Cramer-Rao bounds on the precision of estimates of striatal and background activity concentration. In order to assess the new collimation system to detect changes in striatal activity, the authors evaluated the precision of measuring a 5% decrease in right putamen activity. The authors also reconstructed images of projection data obtained by summing data from the individual phantom compartments. Results: The sensitivity of the novel cone-beam collimator varied with distance from the detector face; it was higher than that of the fan-beam collimator by factors ranging from 2.7 to 162. Examination of the projections of the point sources revealed that only a few holes were distorted or partially blocked, indicating that the intensive manual fabrication process was very successful. Better reconstructed phantom images were obtained from the USCB+FAN collimator pair than from either LEHR or FAN collimation. For the left caudate, located near the center of the brain, the detected counts were 9.8 (8.3) times higher for UCSB compared with LEHR (FAN), averaged over 60 views. The task-specific SNR for detecting a 5% decrease in putamen uptake was 7.4 for USCB and 3.2 for LEHR. Conclusions: The authors have designed and manufactured a novel collimator for brain SPECT imaging. The sensitivity is much higher than that of a fan-beam collimator. Because of differences between the manufactured collimator and its design, reconstruction of the data requires a measured system matrix. The authors have demonstrated the potential of USCB collimation for improved precision in estimating striatal uptake. The novel collimator may be useful for early detection of Parkinson’s disease, and for monitoring therapy response and disease progression.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Sorbent Based Post-Combustion CO 2 Slipstream Testing

TDA Research, Inc. has developed a low-cost sorbent (alkalized alumina) based technology for post-combustion CO 2 capture. The sorbent runs in an isothermal process for adsorption and regeneration. Neither temperature swing nor pressure swing is needed. TDA designed a system which operated 10 fixed beds to simulate a moving bed process. The flow pattern was optimized to minimize the steam usage for regeneration. An excellent sorbent (Batch 1) was also developed with collaboration with our partner. The sorbent degraded after long term operation. We developed a reprocessing procedure, which can be conducted in situ, to restore the sorbent capture capacity as the fresh sorbent after running for about 1250 hours. The reprocessing extended the sorbent longevity significantly. TDA designed a pilot unit (40’ x 32’ x 11.5’), processing flue gas equivalent to 0.5 MW of power generation. It had 10 beds and each bed could hold 1.75 m 3 of sorbent. We worked with Springs Fabrication, Inc. to complete the construction of the pilot unit. It was then shipped and installed at NCCC. The pilot unit was kept running in 24-hour mode when the flue gas and steam were available. It could run automatically without operator on site. Parametric and long-term (2 months) tests were carried out successfully. The results showed that TDA’s process can achieve 90% capture and 95% CO 2 purity for both coal and NG flue gases. For coal flue gas, the system reached performance target when processing up to 0.62 MW flue gas, 24% higher than the design capacity. Thus, capital cost could be saved on the reactors and sorbent. The strip air flow was designed to be 0.25 of that of the flue gas. The test data showed the strip/flue ratio can be reduced to as little as 0.18, which saves the power consumption for the strip air blower. The pressure drop was found to be lower than what the empirical equation calculated. The sorbent still had 91.7% of original capacity after 3-month test. With the data from the pilot test, we updated the TEA. For a 550-MW e supercritical coal fired power plant with CO 2 capture, the capture cost for TDA’s process is $34.9/tonne CO 2 captured, which meets DOE’s goal of $40/tonne and is 17.1% less than the DOE baseline Case 12. Therefore, TDA’s process has a good potential for commercialization.

01 COAL, LIGNITE, AND PEAT↗
NASA NTRSDate not supplied

Accommodation of Posture Variations in Lower Head for Maxillofacial Protective Equipment Design

In order to optimize maxillofacial protective equipment design for Soldiers, the face shape and size were analyzed for changes from a baseline neutral pose to functional poses or jaw motions. A dynamic 3D scanner captured the head and face shapes in several different poses, for example, pronouncing vowel sounds or mimicking yawning or chewing. The face landmarks showed unique excursion patterns, not represented in “static” anthropometry, for example, a 49 mm downward chin motion when yawning. A design demo was simulated to show the mandible shield size required to accommodate the different poses.

Han Kim↗
NASA NTRS1989

VLSI processors for signal detection in SETI

The objective of the Search for Extraterrestrial Intelligence (SETI) is to locate an artificially created signal coming from a distant star. This is done in two steps: (1) spectral analysis of an incoming radio frequency band, and (2) pattern detection for narrow-band signals. Both steps are computationally expensive and require the development of specially designed computer architectures. To reduce the size and cost of the SETI signal detection machine, two custom VLSI chips are under development. The first chip, the SETI DSP Engine, is used in the spectrum analyzer and is specially designed to compute Discrete Fourier Transforms (DFTs). It is a high-speed arithmetic processor that has two adders, one multiplier-accumulator, and three four-port memories. The second chip is a new type of Content-Addressable Memory. It is the heart of an associative processor that is used for pattern detection. Both chips incorporate many innovative circuits and architectural features.

NASA Program Exobiology↗
NASA NTRS1975

One-third scale model of an offset fed scanning antenna for the shuttle imaging microwave system

An experimental study is reported, involving the design, fabrication, and measurement of a one-third scale model of the 4m diameter parabolic torus reflector with a Gregorian feed for the SIMS application. Antenna pattern measurements of the model at 60 and 30 GHz are presented to verify the predictions of a geometrical optics analysis upon which the antenna design was based. It is shown that the antenna measurements bear out the geometrical optics analysis in every respect and that the Gregorian subreflector feed is usable at all frequencies above at least 10 Ghz in the full size SIMS antenna. The fabrication of the model antenna is discussed, including a computerized technique for fabricating the transcendental subreflector shape with a numerically controlled machine.

Gustincic, J. H.↗
NASA NTRS1973

Performance of an annual combustor designed for a low-cost turbojet engine

Performance tests were conducted on a combustor designed for use in a low-cost turbojet engine. Low-cost features included the use of very inexpensive simplex fuel nozzles and combustor liners of perforated sheet material. Combustion efficiencies at the altitude-cruise and sea-level design points were approximately 94 and 96 percent, respectively. The combustor isothermal total-pressure loss was 8.8 percent at the altitude-cruise-condition diffuser-inlet Mach number of 0.335. The combustor-exit temperature pattern factor was less than 0.3 at the altitude-cruise, sea-level-cruise, and sea-level-static design conditions. The combustor-exit average radial temperature profiles at all conditions were in very good agreement with the design profile. The intense mixing required because of the very high combustor heat-release rate had an adverse effect on ignition capability at altitude windmilling design conditions.

Fear, J. S.↗
DOE OSTI2018

Molecular association model of PPARα and its new specific and efficient ligand, pemafibrate: Structural basis for SPPARMα

Highlights: • Computationally constructed the structure of hPPARα in a complex with pemafibrate. • Structural basis for potent effects of pemafibrate predicted by in silico FMO method. • Computational results were confirmed by in vitro luciferase assay analysis. • Unlike fibrates, pemafibrate binds efficiently that makes it as a novel SPPARMα. Peroxisome proliferator-activated receptor-α (PPARα) is a ligand-activated transcription factor involved in the regulation of lipid homeostasis and improves hypertriglyceridemia. Pemafibrate is a novel selective PPARα modulator (SPPARMα) that activates PPARα transcriptional activity. Here, we computationally constructed the structure of the human PPARα in a complex with pemafibrate, along with that of hPPARα complexed with the classical fenofibrate, and studied their interactions quantitatively by using the first-principles calculations-based fragment molecular orbital (FMO) method. Comprehensive structural and protein-ligand binding elucidation along with the in vitro luciferase analysis let us to identify pemafibrate as a novel SPPARMα. Unlike known fibrate ligands, which bind only with the arm I of the Y-shaped ligand binding pocket, the Y-shaped pemafibrate binds to the entire cavity region. This lock and key nature causes enhanced induced fit in pemafibrate-ligated PPARα. Importantly, this selective modulator allosterically changes PPARα conformation to form a brand-new interface, which in turn binds to PPARα co-activator, PGC-1α, resulting in the full activation of PPARα. The structural basis for the potent effects of pemafibrate on PPARα transcriptional activity predicted by the in silico FMO methods was confirmed by in vitro luciferase assay for mutants. The unique binding mode of pemafibrate reveals a new pattern of nuclear receptor ligand recognition and suggests a novel basis for ligand design, offering cues for improving the binding affinity and selectivity of ligand for better clinical consequences. The findings explain the high affinity and efficacy of pemafibrate, which is expected to be in the clinical use soon.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Signatures of the unique microstructure of additively manufactured steel observed via diffraction

A series of measurements were designed to gain confidence in the interpretation of the peak breadth in diffraction patterns collected from additively manufactured material, which has a novel microstructure in comparison to the well understood microstructure of wrought materials. Stainless steels made with two additive manufacturing techniques were compared to wrought material. Similar patterns observed in the scattering vector dependence for additively manufactured and deformed wrought materials suggested that the broadening in both materials was related to dislocations. Finally, this was confirmed by heat-treatment, during which both materials exhibited recovery due to the annealing of dislocations at the same temperature.

304L stainless-steel↗
DOE OSTI2024

Heat Transport Hysteresis Generated Through Frequency Switching of a Time-Dependent Temperature Gradient

A stochastic energetics framework is applied to examine how periodically shifting the frequency of a time-dependent oscillating temperature gradient affects heat transport in a nanoscale molecular model. We specifically examine the effects that frequency switching, i.e., instantaneously changing the oscillation frequency of the temperature gradient, has on the shape of the heat transport hysteresis curves generated by a particle connected to two thermal baths, each with a temperature that is oscillating in time. Analytical expressions are derived for the energy fluxes in/out of the system and the baths, with excellent agreement observed between the analytical expressions and the results from nonequilibrium molecular dynamics simulations. We find that the shape of the heat transport hysteresis curves can be significantly altered by shifting the frequency between fast and slow oscillation regimes. We also observe the emergence of features in the hysteresis curves such as pinched loops and complex multi-loop patterns due to the frequency shifting. The presented results have implications in the design of thermal neuromorphic devices such as thermal memristors and thermal memcapacitors.

36 MATERIALS SCIENCE↗
NASA NTRS1973

Remote analysis of planetary soils: X-ray diffractometer development

A system is described suitable for remote low power mineralogical analysis of lunar, planetary, or asteroid soils. It includes an X-ray diffractometer, fluorescence spectrometer, and sample preparation system. A one Curie Fe-55 source provides a monochromatic X-ray beam of 5.9 keV. Seeman-Bohlin or focusing geometry is employed in the camera, allowing peak detection to proceed simultaneously at all angles and obviating the need for moving parts. The detector system is an array of 500-600 proportional counters with a wire-spacing of 1 mm. An electronics unit comprising preamplifier, postamplifier, window discriminators, and storage flipflops requiring only 3.5 milliwatts was designed and tested. Total instrument power is less than 5 watts. Powder diffraction patterns using a flat breadboard multiwire counter were recorded.

Gregory, J. C.↗
NASA NTRS1975

Horn antenna with v-shaped corrugated surface

Corrugated shape is easily machined for millimeter wave application and is better suited for folding antenna designs. Measured performance showed ""V'' corrugations and rectangular corrugations have nearly the same pattern beamwidth, gain, and impedance. Also, ""V'' corrugations have higher relative power loss.

Beck, F. B.↗
NASA NTRS1973

Study of the marine environment of the northern Gulf of California

The author has identified the following significant results. Results of studies of the oceanography of the northern Gulf of California (Mexico) are reported. A remote, instrumented buoy measuring and telemetering oceanographic data by ERTS-1 satellite was designed, constructed, deployed, and tested. Regular cruises by a research ship on a pattern of 47 oceanographic stations collected data which are analyzed and referenced to analysis of ERTS-1 satellite imagery. A thermal dynamic model of current patterns in the northern Gulf of California is proposed. Findings are examined in relation to the model.

Hendrickson, J. R.↗
NASA NTRS1976

Guidelines for multiple LSI packaging

Handbook provides specific guidelines related to ceramic multilayer circuit fabrication in terms of packaging density and interconnection methods, guiding the designer from initial stages of ceramic multilayer interconnection and artwork generation through test pattern utilization, assembly operations, and final inspection and test procedures.

Peckinpaugh, C. J.↗