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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 1,531 records · Page 85
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Status Update: Modeling Energy Balance in NIF Hohlraums

We have developed a standardized methodology to model hohlraum drive in NIF experiments. We compare simulation results to experiments by 1) comparing hohlraum xray fluxes and 2) comparing capsule metrics, such as bang times. Long-pulse, high gas-fill hohlraums require a 20-28% reduction in simulated drive and inclusion of ~15% backscatter to match experiment through (1) and (2). Short-pulse, low fill or near-vacuum hohlraums require a 10% reduction in simulated drive to match experiment through (2); no reduction through (1). Ongoing work focuses on physical model modifications to improve these matches.

42 ENGINEERING↗
DOE OSTI2016

Search for New Physics and Upgrade of the ATLAS Muon Spectrometer at the LHC

I report the research activities that my group has with the ATLAS (A Toroidal LHC ApparatuS) experiment at the Large Hadron Collider (LHC). The research focused on searches for new physics phenomena beyond the Standard Model (SM) using dilepton and diboson final states, on SM measurements with diboson, triboson and vector boson scattering processes, on the development of Phase-0, Phase-1 and Phase-2 upgrades of the ATLAS muon spectrometer.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

Evolution in Cloud Population Statistics of the MJO: From AMIE Field Observations to Global Cloud-Permiting Models

Motivated by the success of the AMIE/DYNAMO field campaign, which collected unprecedented observations of cloud and precipitation from the tropical Indian Ocean in Octber 2011 – March 2012, this project explored how such observations can be applied to assist the development of global cloud-permitting models through evaluating and correcting model biases in cloud statistics. The main accomplishment of this project were made in four categories: generating observational products for model evaluation, using AMIE/DYNAMO observations to validate global model simulations, using AMIE/DYNAMO observations in numerical studies of cloud-permitting models, and providing leadership in the field. Results from this project provide valuable information for building a seamless bridge between DOE ASR program’s component on process level understanding of cloud processes in the tropics and RGCM focus on global variability and regional extremes. In particular, experience gained from this project would be directly applicable to evaluation and improvements of ACME, especially as it transitions to a non-hydrostatic variable resolution model.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Tracking Aerosol Convective Interactions Experiment (TRACER) Science Plan

Convective clouds play an important role in the Earth’s climate system as a driver of large-scale circulations and a primary mechanism for the transport of heat, moisture, aerosols, and momentum throughout the troposphere. Despite their climatic importance, multi-scale models continue to have persistent biases produced by insufficient representation of convective clouds. This is the result of an incomplete understanding of key processes such as convective initiation, updraft and downdraft dynamics, cloud and precipitation microphysics, and aerosol-convection interactions. The Aerosol-Cloud-Precipitation-Climate Initiative, an international research group dedicated to advancing understanding of aerosol impacts on clouds relevant to climate, has identified the Houston, Texas region as an optimal location for targeted studies of aerosol-convection interactions within frequently developing isolated deep convection. Houston lies within a humid subtropical climate regime, where onshore flow and sea-breeze convection interact with a range of aerosol conditions associated with Houston’s urban and industrial emissions. Pilot studies have suggested that convective clouds in this region are potentially significantly impacted by the varying aerosol conditions. To increase our understanding of convective cloud life cycles and aerosol-convection interactions, the Tracking Aerosol Convection Interactions Experiment (TRACER) aims to collect a comprehensive data set focused on the evolution of convective clouds and the environment (including aerosol, cloud, thermodynamics, and lightning) in which the clouds initiate, grow, and decay. A unique component of TRACER is that a large number of individual, isolated convective cells will be tracked and measured in high spatial and temporal resolution for the purposes of: (i) Characterizing and linking convective cloud kinematic and microphysical life cycles, (ii) Quantifying environmental thermodynamic and kinematic controls on convective life cycle properties, (iii) Isolating and quantifying the impacts of aerosol properties on convective cloud kinematic and microphysical evolution. TRACER includes a one-year deployment of the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) user facility’s first ARM Mobile Facility (AMF1) and second-generation C-Band Scanning ARM Precipitation Radar (CSAPR2) aimed at collecting statistical data sets of cloud, precipitation, atmospheric state, and aerosol under varying aerosol loading and local circulation (sea breeze and urban heat island) conditions. A four-month intensive operational period (IOP) from June through September will include deployment of an ancillary site with aerosol, atmospheric state, and precipitation measurements at a location rarely impacted by Houston’s anthropogenic emissions, which will be commonplace near the AMF1 site. Convective cell tracking by the CSAPR2 will provide high-resolution polarimetric and velocity observations under a range of environmental (including aerosol loading) conditions. High-frequency radiosonde launches will capture quickly evolving thermodynamic and kinematic conditions near convective cells, a requirement for isolating aerosol effects on clouds. TRACER will additionally leverage a lightning mapping array, surface meteorological networks, and air pollution networks, and proposals will be entered to deploy additional mobile radar and radiosonde assets during the IOP. This unique combination of cloud, precipitation, lightning, aerosol, and atmospheric state measurements associated with tracked convective cells will ultimately improve our understanding of the convective cloud life cycle and its interaction with individual environmental factors such that improved, next-generation cumulus, microphysics, turbulence, and aerosol parameterizations can be designed.

Convective clouds, aerosols, cloud life cycle, atm↗
DOE OSTI2019

Thrust #3: Simulation and Measurement of Bio-enabled Lensless Infrared Focusing and Spatially-Controlled Multiwavelength IR reflection

The path to quantitatively characterizing the possible impact of refractive index on the focusing behavior of C. Wailesii diatoms frustules and their replicas first required the careful design of a control experiment that allowed for judicious control of both material and hole pattern variables, which are thought to govern focusing behavior. This was accomplished by FIB-milling synthetic hole patterns with well-controlled dimensions into thin SiO 2 and MgO/Si films. In doing so, an ideal sample is obtained whose pore patterns can be simulated via beam propagation methods and whose relatively simple interference patterns can be measured by far-field diffraction imaging. Together with refractive index measurements via ellipsometry on SiO 2 and MgO/Si thin films, these results showed that the focusing distances at six different wavelengths over 550-1050 nm are strongly correlated with the dispersion of the refractive index in this range. Although assertions have been made to this point in the literature, the results given here presented an improved characterization of the role that refractive index played in focusing behavior in a “diatom-like” hole pattern that otherwise is missing in earlier works due to inadequate characterization of refractive index dispersion and poor control over hole pattern dimensions. These results provided a reference point with which measurements and simulations of diatoms and their replicas can be compared.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2022

Progress Report on SFR Metallic Fuel Data Qualification

This report summarizes the progress of SFR metallic fuel qualification related activities, which are focused on providing quality assurance relevant information applicable to experiments irradiated during the Integral Fast Reactor (IFR) program. A background of metallic fuel performance data and the associated databases, including the EBR-II Fuels Irradiation & Physics Database (FIPD) and Out-of-Pile Transient Database (OPTD), is included. The legacy data in the databases, including as-built, post-irradiation examination (PIE), operating parameters, and out-of-pile experiment data are introduced. The SFR metallic fuel Quality Assurance Program Plan (QAPP) and its implementation to qualify these legacy data is described in detail. Important PIE data QA documents and the specifications of four types of PIE measurements (contact profilometry, laser profilometry, neutron radiography and gamma scan) are provided. Examples of the implementation of the QAPP to qualify each of those types of PIE data are provided.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2024

Gordon Research Conference Technical Report

This grant supported travel and conference fees for participants in the 2022 Gordon Research Conference (GRC) and Gordon Research Seminar (GRS) on Rock Deformation. The theme of the conference was “Combining Laboratory Measurements with Observational Constraints to Understand Tectonic Processes”, which focused on how to scale up observations from laboratory experiments to tectonic processes. Dan Faulkner (Univ. of Liverpool) was the GRC chair and Heather Savage (UC Santa Cruz) was the vice chair. The GRS was run by Carolyn Tewksbury-Christle and Taka Kanaya. The majority of the funds from this grant supported early career researchers.

58 GEOSCIENCES↗
DOE OSTI2026

Progress Report on SFR Metallic Fuel Data Qualification

This report summarizes the progress of SFR metallic fuel qualification related activities, which are focused on providing quality assurance relevant information applicable to experiments irradiated during the Integral Fast Reactor (IFR) program. An overview of the metallic fuel performance data and the associated databases, including the EBR-II Fuels Irradiation & Physics Database (FIPD), Out-of-Pile Transient Database (OPTD), and TREAT Experimental Relational Database (TREXR) is included. The legacy data in the databases, including as-built, post-irradiation examination (PIE), operating parameters, and out-of-pile experiment post-test data are introduced. The SFR metallic fuel Quality Assurance Program Plan (QAPP) and its implementation to qualify these legacy data is described in detail. Important PIE data QA documents and the specifications of seven types of PIE measurements (contact profilometry, laser profilometry, neutron radiography, gamma scan, fission gas release fission gas chemistry, and metallography) are provided. Examples of the implementation of the QAPP to qualify each of those types of PIE data are provided.

Mo, Kun [Argonne National Laboratory (ANL), Argonn↗
DOE OSTI2019

CFD-Guided Combustion System Optimization of a Gasoline Range Fuel in a Heavy-Duty Compression Ignition Engine Using Automatic Piston Geometry Generation and a Supercomputer

A computational fluid dynamics (CFD) guided combustion system optimization was conducted for a heavy-duty diesel engine running with a gasoline fuel that has a research octane number (RON) of 80. The goal was to optimize the gasoline compression ignition (GCI) combustion recipe (piston bowl geometry, injector spray pattern, in-cylinder swirl motion, and thermal boundary conditions) for improved fuel efficiency while maintaining engine-out NO x within a 1-1.5 g/kW-hr window. The numerical model was developed using the multi-dimensional CFD software CONVERGE. A two-stage design of experiments (DoE) approach was employed with the first stage focusing on the piston bowl shape optimization and the second addressing refinement of the combustion recipe. For optimizing the piston bowl geometry, a software tool, CAESES, was utilized to automatically perturb key bowl design parameters. This led to the generation of 256 combustion chamber designs evaluated at several engine operating conditions. The second DoE campaign was conducted to optimize injector spray patterns, fuel injection strategies and in-cylinder swirl motion for the best performing piston bowl designs from the first DoE campaign. This comprehensive optimization study was performed on a supercomputer, Mira, to accelerate the development of an optimized fuel-efficiency focused design. Compared to the production combustion system in the baseline engine, the new combustion recipe from this study showed significantly improved closed-cycle fuel efficiency across key engine operating points while meeting the engine-out NO x targets. Optimized piston bowl designs and injector spray patterns were predicted to provide enhanced in-cylinder air utilization and more rapid mixing-controlled combustion, thereby leading to a fuel efficiency improvement. In addition, shifting the engine thermal boundary conditions toward leaner operation was also key to the improved fuel efficiency.

33 ADVANCED PROPULSION SYSTEMS↗
NASA NTRS1980

Plasma collection by high voltage spacecraft at low earth orbit

A computer model of the three-dimensional sheath formation and plasma current collection by high voltage spacecraft has been developed. By using new space charge density and plasma collection algorithms, it is practical to perform calculations for large, complex spacecraft. The model uses NASCAP compatible objects and geometries. Results indicate that ion focusing observed in the laboratory during high voltage collection experiments is probably due to voltage gradients on the collecting surfaces.

Katz, I.↗
NASA NTRS1981

Visual fatigue - The need for an integrated model

Two experiments were conducted to examine possible decrements in performance over time on two visual tracking tasks. In Experiment 1, six subjects tracked a horizontal, sinusoidally moving target in the picture plane for 6.5 min. In Experiment 2, six subjects tracked a target sinusoidally changing focus in the depth plane between 0 and 4 D over 6.5 min. Results indicated a linearly decreasing amplitude of both pursuit eye movements (.29 deg of visual angle per minute) and accommodation (.11 D/min). These visual fatigue effects are discussed in the context of several competing explanations.

Malmstrom, F. V.↗
NASA NTRS1989

Photochemical stability of CO2 in the Martian atmosphere - Reevaluation of the eddy diffusion coefficient and the role of water vapor

Theoretical models of CO2 photodissociation in the atmosphere of Mars are developed and analyzed, with a focus on the conditions prevailing during the Mariner 6/7 experiments. The aeronomy of Martian CO2 is reviewed; the atomic O distribution in the upper atmosphere is characterized; the construction of the basic model is described; and simulation results are presented in extensive tables and graphs and discussed in detail. The vertical eddy-diffusion coefficient corresponding to the estimated upper-atmosphere O density (1-2 percent at 135 km) is found to be about 5 x 10 to the 7th sq cm/sec, and HO(x) is found to play a significant role in catalyzing the recombination of CO and O to form CO2. The reasons why the model overpredicts the production of HO(x) and hence of CO2 are explored.

Shimazaki, Tatsuo↗
NASA NTRS1991

Ka-band mobile and personal systems development at JPL

Expanding the commercial applications of space is one of the primary goals of NASA. Throughout the eighties NASA has pursued this objective by sponsoring and undertaking the development of system concepts, enabling high risk technologies, and actual proof of concept demonstration hardware. In the mobile and personal arena, or the so-called low data rate applications area, JPL is NASA's lead center. JPL's focus of activities has been the Mobile Satellite-Experiment (MSAT-X) project, which developed mobile communication technologies at L-band, and its present successors, which aim to expand the mobile arena by exploiting Ka-band.

Dessouky, K.↗
NASA NTRS1991

Determination of the Critical Parameters for Remote Microscope Control

As part of a program to determine the capabilities of Telescience as applied to Microgravity Materials Science the need for a remotely controlled microscope was recognized. For this purpose we equipped a microscope with an X-Y-Z positioning device and motors on the zoom and focus controls. Computer control of these devices allowed remote operation. A standard TV camera was mounted to the computer controlled video board which could compress the image in resolution and grey scale. The operator control console was programmed to display three still video pictures as well as provide command access. A standard data transfer network was used to transmit the video data files and the command interaction was via a high speed phone modem. This system, with the microscope in the Microgravity Materials Science Laboratory (MMSL) at LeRC and the control at RPI, was used to determine the accuracy of setting, time required to achieve setting and the operator ease factor. It was found that the focus setting could be established well within the resolution limit of the TV system and that each motion took about 50 seconds and approximately 12 minutes was required to reach ?best? focus. These times could be reduced significantly with operator experience. The operators were provided with ancillary equipment which provided assistance in making the necessary decisions and they reported satisfaction with the control.

Hahn, R. C.↗
NASA NTRS1994

GPS Measurements Show Subdaily Changes In Earth Rotation

Report presents analysis of data from 3-week worldwide Global Positioning System (GPS) tracking experiment conducted from January 22 through February 14, 1991. Focus of analysis upon detection and interpretation of subdaily variations in rate of rotation of earth.

Lichten, Stephen M.↗
NASA NTRS1994

Design and application of electromechanical actuators for deep space missions

This progress report documents research and development efforts performed from August 16, 1993 through August 15, 1994 on NASA Grant NAG8-240, 'Design and Application of Electromechanical Actuators for Deep Space Missions.' Since the submission of our last progress report in February 1994, our efforts have been almost entirely focused on final construction of the test stand and experiment design. Hence, this report is dedicated solely to these topics. However, updates on our research personnel and our health monitoring and fault management efforts are provided in this summary. Following this executive summary are two report sections. The first is devoted to the motor drive being constructed for the test stand. The thrust of the next section is the mechanical and hydraulic design and construction based on the planned experimental requirements. Following both major sections are three appendices.

Haskew, Tim A.↗
NASA NTRS1994

Composite chronicles: A study of the lessons learned in the development, production, and service of composite structures

A study of past composite aircraft structures programs was conducted to determine the lessons learned during the programs. The study focused on finding major underlying principles and practices that experience showed have significant effects on the development process and should be recognized and understood by those responsible for using of composites. Published information on programs was reviewed and interviews were conducted with personnel associated with current and past major development programs. In all, interviews were conducted with about 56 people representing 32 organizations. Most of the people interviewed have been involved in the engineering and manufacturing development of composites for the past 20 to 25 years. Although composites technology has made great advances over the past 30 years, the effective application of composites to aircraft is still a complex problem that requires experienced personnel with special knowledge. All disciplines involved in the development process must work together in real time to minimize risk and assure total product quality and performance at acceptable costs. The most successful programs have made effective use of integrated, collocated, concurrent engineering teams, and most often used well-planned, systematic development efforts wherein the design and manufacturing processes are validated in a step-by-step or 'building block' approach. Such approaches reduce program risk and are cost effective.

Vosteen, Louis F.↗
NASA NTRS1995

STS-84 Day 04 Highlights

On this fourth day of the STS-84 mission, the flight crew, Cmdr. Charles J. Precourt, Pilot Eileen M. Collins, Payload Cmdr, Jean-Francois Clervoy (ESA), Mission Specialists Edward T. Lu, Carlos I. Noriega, Elena V. Kondakova, Jerry M. Linenger (download), and C. Michael Foale (upload) spend their first full day of work together conducting science investigations and transferring equipment from one spacecraft to the other. The Spacehab double module at the rear of Atlantis' payload bay was the focus of activity today as crew members conducted science experiments in the Biorack facility and transferred items to and from the Mir Space Station. In an interview with CBS News, Precourt and Tsibliev praise the sixth joint docking mission between the U.S. and Russia, indicating it is serving as a worthwhile exercise to prepare for the assembly of the International Space Station. Precourt also said the Mir appears to be in good condition despite recent systems problems, and said Mir will be a perfectly safe home for Foale for his stay on orbit.

Source record↗