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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 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
NASA NTRS2021

ED1: Design and Prototype of a 3D Printed Wind Tunnel Model with Integrated Force Measurement

Wind tunnel testing using conventionally manufactured force measurement systems (balances) is able to yield precise and accurate results. These balances are delicate, complex instruments. Due to the nature of this high-precision complexity, balances are expensive and time-consuming to produce. These factors can limit the design potential of the model because using conventionally manufactured balances generally means that the model is designed to accommodate balances that already exist. Ideally, engineers would be able to design a measurement system that is tailored to fit the needs of the model, rather than the other way around. The goal of this research project was to determine if it is possible to overcome these drawbacks by designing a wind tunnel model with a modifiable integrated force measurement system that leverages additive manufacturing. This was undertaken by utilizing the existing UT-63 wind tunnel balance (measurement system), integrating it with a model based on the existing AGARD-B model, and performing stress analysis to optimize the design. Due to time constraints, the result of this endeavor is currently incomplete. Continued analysis and optimization are required to have a thorough understanding of the success or failure of the attempted design. As additive manufacturing technology evolves, the ability for it to become the primary method of fabrication for sensitive measurement systems increases. This project contributes to this by providing one method for design, a framework for optimizing existing balances for additive manufacturing, and resources for performing necessary stress analysis.

Callie Ellsworth↗
NASA NTRS2007

V-Man Generation for 3-D Real Time Animation

The V-Man project has developed an intuitive authoring and intelligent system to create, animate, control and interact in real-time with a new generation of 3D virtual characters: The V-Men. It combines several innovative algorithms coming from Virtual Reality, Physical Simulation, Computer Vision, Robotics and Artificial Intelligence. Given a high-level task like "walk to that spot" or "get that object", a V-Man generates the complete animation required to accomplish the task. V-Men synthesise motion at runtime according to their environment, their task and their physical parameters, drawing upon its unique set of skills manufactured during the character creation. The key to the system is the automated creation of realistic V-Men, not requiring the expertise of an animator. It is based on real human data captured by 3D static and dynamic body scanners, which is then processed to generate firstly animatable body meshes, secondly 3D garments and finally skinned body meshes.

Nebel, Jean-Christophe↗
NASA NTRS2009

Video-Game-Like Engine for Depicting Spacecraft Trajectories

GoView is a video-game-like software engine, written in the C and C++ computing languages, that enables real-time, three-dimensional (3D)-appearing visual representation of spacecraft and trajectories (1) from any perspective; (2) at any spatial scale from spacecraft to Solar-system dimensions; (3) in user-selectable time scales; (4) in the past, present, and/or future; (5) with varying speeds; and (6) forward or backward in time. GoView constructs an interactive 3D world by use of spacecraft-mission data from pre-existing engineering software tools. GoView can also be used to produce distributable application programs for depicting NASA orbital missions on personal computers running the Windows XP, Mac OsX, and Linux operating systems. GoView enables seamless rendering of Cartesian coordinate spaces with programmable graphics hardware, whereas prior programs for depicting spacecraft trajectories variously require non-Cartesian coordinates and/or are not compatible with programmable hardware. GoView incorporates an algorithm for nonlinear interpolation between arbitrary reference frames, whereas the prior programs are restricted to special classes of inertial and non-inertial reference frames. Finally, whereas the prior programs present complex user interfaces requiring hours of training, the GoView interface provides guidance, enabling use without any training.

Upchurch, Paul R.↗
NASA NTRS1991

Doppler global velocimetry

A new program to develop a Doppler Global Velocimeter (DGV) for application in the High angle-of-Attack Technology Program is discussed. The Flight research instrument system will make non-intrusive multicomponent velocity measurements of the vortical flow field around an aircraft in flight. The DGV will provide a means to obtain airborne experimental data to evaluate and refine computational fluid dynamic models and to correlate with wind-tunnel data sets. The primary use of the instrument system will be to provide a flexible research tool to map the 3D velocity field at various locations around an aircraft during high angle-of-attack maneuvers at subsonic, transonic, and supersonic speeds. Other potential applications may include shock definition and interactions, external stores flow interactions, rotary flow field definition, non-steady flow field definition, measurement of inlet and duct flow field, and measurement of hypersonic flow field in flight.

Usry, Jim↗
NASA NTRS1999

Inlet Spillage Drag Predictions Using the AIRPLANE Code

AIRPLANE (Jameson/Baker) is a steady inviscid unstructured Euler flow solver. It has been validated on many HSR geometries. It is implemented as MESHPLANE, an unstructured mesh generator, and FLOPLANE, an iterative flow solver. The surface description from an Intergraph CAD system goes into MESHPLANE as collections of polygonal curves to generate the 3D mesh. The flow solver uses a multistage time stepping scheme with residual averaging to approach steady state, but R is not time accurate. The flow solver was ported from Cray to IBM SP2 by Wu-Sun Cheng (IBM); it could only be run on 4 CPUs at a time because of memory limitations. Meshes for the four cases had about 655,000 points in the flow field, about 3.9 million tetrahedra, about 77,500 points on the surface. The flow solver took about 23 wall seconds per iteration when using 4 CPUs. It took about eight and a half wall hours to run 1,300 iterations at a time (the queue limit is 10 hours). A revised version of FLOPLANE (Thomas) was used on up to 64 CPUs to finish up some calculations at the end. We had to turn on more communication when using more processors to eliminate noise that was contaminating the flow field; this added about 50% to the elapsed wall time per iteration when using 64 CPUs. This study involved computing lift and drag for a wing/body/nacelle configuration at Mach 0.9 and 4 degrees pitch. Four cases were considered, corresponding to four nacelle mass flow conditions.

Thomas, Scott D.↗
NASA NTRS2018

Planetary Spectrum Generator: An Accurate Online Radiative Transfer Suite for Atmospheres, Comets, Small Bodies and Exoplanets

We have developed an online radiative-transfer suite (https://psg.gsfc.nasa.gov) applicable to a broad range of planetary objects (e.g., planets, moons, comets, asteroids, TNOs, KBOs, exoplanets). The Planetary Spectrum Generator (PSG) can synthesize planetary spectra (atmospheres and surfaces) for a broad range of wavelengths (UV/Vis/near-IR/IR/far-IR/THz/sub-mm/Radio) from any observatory (e.g., JWST, ALMA, Keck, SOFIA), any orbiter (e.g., ExoMars, Juno), or any lander (e.g., MSL). This is achieved by combining several state-of-the-art radiative transfer models, spectroscopic databases and planetary databases (i.e., climatological and orbital). PSG has a 3D (three-dimensional) orbital calculator for most bodies in the solar system, and all confirmed exoplanets, while the radiative-transfer models can ingest billions of spectral signatures for hundreds of species from several spectroscopic repositories. It integrates the latest radiative-transfer and scattering methods in order to compute high resolution spectra via line-by-line calculations, and utilizes the efficient correlated-k method at moderate resolutions, while for computing cometary spectra, PSG handles non-LTE and LTE excitation processes. PSG includes a realistic noise calculator that integrates several telescope/instrument configurations (e.g., interferometry, coronagraphs) and detector technologies (e.g., CCD, heterodyne detectors, bolometers). Such an integration of advanced spectroscopic methods into an online tool can greatly serve the planetary community, ultimately enabling the retrieval of planetary parameters from remote sensing data, efficient mission planning strategies, interpretation of current and future planetary data, calibration of spectroscopic data, and development of new instrument/spacecraft concepts.

Villanueva, G. L.↗
NASA NTRSDate not supplied

Uninhabited Aerial System Drop-in Balloon-Borne Radiosonde Alternative for Lower Tropospheric Flights

Balloon-borne radiosonde sensors are a well characterized way of gathering data into the stratosphere; however, balloon launches have limitations such as the need to replace the balloon and sensors after each flight, as well the overall drift of the balloon over the course of the launch. Using sensors mounted on an uninhabited aerial system (UAS) allows for higher temporal-resolution vertical profiles in the lower troposphere and allows for full control of the flight profile of the sensors. This paper presents a drop-in solution for a balloon-borne radiosonde in which it is mounted on an uninhabited aerial system in lieu of a balloon with an additional connection to a 3D anemometer streaming atmospheric and wind data in near real-time to a ground station. This alternative platform for balloon-borne radiosondes has undergone extensive flight testing with the wind results being compared against a ground-based wind LiDAR for validation and the atmospheric results undergoing further data analysis against a wide variety of sensors for future validation. Indoor tests were also conducted and are discussed in order to determine the propeller’s influence on the anemometer. This alternative platform will allow for higher temporal and spatial resolution of atmospheric data collection in near-real time.

Tyler L. Willhite↗
NASA NTRS2024

Preventing Camera Clipping Through Varied Terrain and Other Planetary Objects

Within the scope of computer visualization systems and technologies, camera objects allow users to navigate three-dimensional (3D) scenes much like a person would navigate the real world. As such, when one seeks to model a scene or environment based on real-world laws, the camera must often follow these same conventions. Accomplishing this in the world of computer renderings presents unique challenges for defining space, spatial relations, depth, distance, and height. Therefore, movement for a camera must be specifically designated and processed by the program in order to achieve accurate movement representations. Although this thought process involves each aspect of camera movement, one specific aspect of camera movement is the primary focus of this report: ensuring that the camera does not clip through an object and appear subsurface. This is important to mimic real-world movements because people in the real world would not go beneath the solid-surface terrain unless they intended to do so. By working with numerical definitions, equations, and variables, a computer can relate an object to its existence in space. Thus, such challenges in camera movements with computationally rendered 3D spaces can be mitigated.

Kristie O'Brien↗
NASA NTRSDate not supplied

In Space Manufacturing and Extraterrestrial Construction: How Did We Get Here?Where Are We? Where Should We Be Going? THE CHALLENGE: Will We Be Ready?

NASA has held multiple workshops and sought inputs from a broad spectrum of sources, including international partners, other space agencies, industry, large and small businesses, academia, and private citizens to develop its Moon to Mars Strategy and Objectives. The goals and objectives set forth in the resulting documents are “designed to achieve the vision to create a blueprint for sustained human presence and exploration throughout the solar system.” The objectives were categorized into four distinct tracks: Operations, Infrastructure, Transportation and Habitation, and Science. In addition, common themes across the objectives were captured under Recurring Tenets. Within the Infrastructure category, several objectives directly address the need for manufacturing and construction on the lunar surface to support continuous human lunar presence and a robust lunar economy. In exploring the vision for creation of on-demand infrastructure on the lunar surface and beyond, this presentation will examine the development of these capabilities, starting in the late 1990’s and early 2000’s, up to the current state, and offer a perspective on the challenges facing operational implementation of these technologies. In the early 2000’s, the destination was the Moon. The International Space Station (ISS) was to be the test bed for demonstration of in space manufacturing technologies. Additive construction was in its infancy. These pioneering initiatives, having begun primarily under NASA’s Office of Biological and Physical Research In Situ Fabrication and Repair (ISFAR) Project, were short-lived. It was not until the early 2010’s that in space manufacturing and later extraterrestrial construction experienced renewed interest and support. At this time, the destination was Mars. This period saw the initial in space additive manufacturing experiments on the ISS, creation of a roadmap for development of in space manufacturing technologies, and development of additive construction systems for terrestrial use at scale. The period also included NASA’s 3D Printed Mars Habitat Centennial Challenge, which catalyzed interest in extraterrestrial construction. With NASA’s announcement of the intention to return to the Moon, and the subsequent release of the Artemis Accords in 2020, and the commensurate Moon to Mars Strategy, NASA’s Space Technology Mission Directorate initiated the Lunar Surface Innovation Initiative (LSII). The LSII has spurred technology development and maturation efforts across a spectrum of capabilities that would be needed to live on the lunar surface. The presentation will provide an overview of current technology developments in the areas of in space manufacturing and extraterrestrial construction. Looking forward from the current state, a perspective will be offered on capabilities that are still needed to “institutionalize” in space manufacturing and extraterrestrial construction to achieve the vision of NASA’s Moon to Mars Strategy. Finally, a challenge will be posed to the community to accelerate the development of these capabilities. When the explorers of the future need these enabling capabilities, will they be ready?

Raymond G Clinton Jr.↗
NASA NTRSDate not supplied

Redesign of Carbon Dioxide Removal System for Multifunctional Sorbent Bed Testing

Carbon dioxide removal is a key function of Environmental Control and Life Support System (ECLSS) on the International Space System (ISS). Currently, this system uses pellet beds however they have known issues such as flow channeling and uneven heating. The Multifunction Sorbent (MultiSorb) project is developing 3D-printed zeolite beds with embedded heaters to address these issues. This poster lays out the steps in modifying the Carbon Dioxide Removal and Compression System (CRCS) to test the MultiSorb beds.

MultiSORB↗
NASA NTRS1993

The three-dimensional Multi-Block Advanced Grid Generation System (3DMAGGS)

As the size and complexity of three dimensional volume grids increases, there is a growing need for fast and efficient 3D volumetric elliptic grid solvers. Present day solvers are limited by computational speed and do not have all the capabilities such as interior volume grid clustering control, viscous grid clustering at the wall of a configuration, truncation error limiters, and convergence optimization residing in one code. A new volume grid generator, 3DMAGGS (Three-Dimensional Multi-Block Advanced Grid Generation System), which is based on the 3DGRAPE code, has evolved to meet these needs. This is a manual for the usage of 3DMAGGS and contains five sections, including the motivations and usage, a GRIDGEN interface, a grid quality analysis tool, a sample case for verifying correct operation of the code, and a comparison to both 3DGRAPE and GRIDGEN3D. Since it was derived from 3DGRAPE, this technical memorandum should be used in conjunction with the 3DGRAPE manual (NASA TM-102224).

Alter, Stephen J.↗
NASA NTRS2017

The Intelligent Landing System for Safe and Precise Landing on Europa

Europa, the smallest of Jupiter’s Galilean moons, is thought to harbor a vast liquid water ocean beneath its icy crust, making it one of the most scientifically intriguing targets for a robotic surface sampling mission in our Solar System. However, autonomously landing a spacecraft safely and precisely on Europa poses unique challenges, such as very little existing high-resolution reconnaissance imagery, a surface expected to be very rough and hazardous over a wide range of scales, an extremely intense ionizing radiation environment, and very limited lander resources for mass and volume. To address these challenges, we propose a novel Intelligent Landing System (ILS) combining four Guidance, Navigation & Control (GN&C) sensing functions – velocimetry, altimetry, map-relative localization, and hazard detection – that would together enable safe and precise landing on Europa’s surface. The ILS is a smart sensor system, combining an inertial measurement unit (IMU), a monocular, passive-optical camera, and a light detection and ranging (Li-DAR) sensor with dedicated computing resources as well as an onboard 3D terrain map. The ILS leverages more than a decade of technology development from programs such as the Lander Vision System, currently baselined on the Mars 2020 mission. This paper provides a detailed description of the proposed ILS architecture and concept of operations, as well as select preliminary simulation results to assess performance and robustness.

Trawny, Nikolas↗
NASA NTRS1994

Theoretical Study of the Low-Lying States of TiHe(+),TiNe(+),TiAr(+),VAr(+),CrHe(+),CrAr(+),FeHe(+),FeAr(+),CoHe(+),and CoAr(+)

The potential energy curves for the manifold of molecular states dissociating to the lowest transition metal ion states derived from the 3d(sup n+1) and 3d(sup n)4s(sup 1) occupations have been determined for selected transition-metal ion- rare gas systems. These curves have been computed using large basis sets, and the state-averaged complete- active-space self-consistent-field/multireference configuration interaction level of electron correlation treatment. In general, the families of curves derived from the 3d(sup n+1) and 3d(sup n)4s(sup 1) metal occupations are disjoint; however, for Ti(+) there is a strong mixing of the 3d(sup 2)4s(sup 1) and 3d(sup 3) asymptotes, because of the small separation between the asymptotes. This mixing leads to a failure of single-reference-based techniques; this is discussed in the context of our previous single-reference-based treatments.

Partridge, Harry↗
NASA NTRS2011

A Three-Dimensional Receiver Operator Characteristic Surface Diagnostic Metric

Receiver Operator Characteristic (ROC) curves are commonly applied as metrics for quantifying the performance of binary fault detection systems. An ROC curve provides a visual representation of a detection system s True Positive Rate versus False Positive Rate sensitivity as the detection threshold is varied. The area under the curve provides a measure of fault detection performance independent of the applied detection threshold. While the standard ROC curve is well suited for quantifying binary fault detection performance, it is not suitable for quantifying the classification performance of multi-fault classification problems. Furthermore, it does not provide a measure of diagnostic latency. To address these shortcomings, a novel three-dimensional receiver operator characteristic (3D ROC) surface metric has been developed. This is done by generating and applying two separate curves: the standard ROC curve reflecting fault detection performance, and a second curve reflecting fault classification performance. A third dimension, diagnostic latency, is added giving rise to 3D ROC surfaces. Applying numerical integration techniques, the volumes under and between the surfaces are calculated to produce metrics of the diagnostic system s detection and classification performance. This paper will describe the 3D ROC surface metric in detail, and present an example of its application for quantifying the performance of aircraft engine gas path diagnostic methods. Metric limitations and potential enhancements are also discussed

Simon, Donald L.↗
NASA NTRS1991

Chemical and biological structure and transport of a cool filament associated with a jet-eddy system of northern California in July 1986 (OPTOMA21)

The distributions of nutrient, pigment, bio-optical, and physical variables were mapped in a jet-eddy system off Point Reyes and Point Arena, California, from July 7 to 19, 1986, in order to describe the 3D variability of the filament and its relation to the nutrient and phytoplankton distributions offshore, to examine the interaction between the filament and coastal water, and to estimate the transport of nutrients and phytoplankton by the jet system. Several cool filaments were distinguishable at distances of more than 35-50 km from the coast in satellite imagery during this period. The juxtaposition of these features as well as the presence of an offshore anticyclone and a cyclone south of the filament anchored to the coast at Point Arena led to complex patterns in all variables, aided by the apparent alongshore variability in the source of upwelled water. This structure has implications for the fluxes of organic material in the region and is probably significant in organizing the interactions among different trophic levels within the system.

Jones, Burton H.↗
NASA NTRS1994

Data assimilation and model evaluation experiment datasets

The Institute for Naval Oceanography, in cooperation with Naval Research Laboratories and universities, executed the Data Assimilation and Model Evaluation Experiment (DAMEE) for the Gulf Stream region during fiscal years 1991-1993. Enormous effort has gone into the preparation of several high-quality and consistent datasets for model initialization and verification. This paper describes the preparation process, the temporal and spatial scopes, the contents, the structure, etc., of these datasets. The goal of DAMEE and the need of data for the four phases of experiment are briefly stated. The preparation of DAMEE datasets consisted of a series of processes: (1) collection of observational data; (2) analysis and interpretation; (3) interpolation using the Optimum Thermal Interpolation System package; (4) quality control and re-analysis; and (5) data archiving and software documentation. The data products from these processes included a time series of 3D fields of temperature and salinity, 2D fields of surface dynamic height and mixed-layer depth, analysis of the Gulf Stream and rings system, and bathythermograph profiles. To date, these are the most detailed and high-quality data for mesoscale ocean modeling, data assimilation, and forecasting research. Feedback from ocean modeling groups who tested this data was incorporated into its refinement. Suggestions for DAMEE data usages include (1) ocean modeling and data assimilation studies, (2) diagnosis and theoretical studies, and (3) comparisons with locally detailed observations.

Lai, Chung-Cheng A.↗