Search NASA⌕ Search

SEARCH · Search NASA

Results for “Projective geometries”

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 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Cu11PdN4 by Materials Project

PdCu11N4 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Pd is bonded in a linear geometry to four equivalent Cu and two N atoms. All Pd–Cu bond lengths are 2.67 Å. There is one shorter (1.94 Å) and one longer (1.96 Å) Pd–N bond length. There are five inequivalent Cu sites. In the first Cu site, Cu is bonded in a linear geometry to four equivalent Cu and two N atoms. All Cu–Cu bond lengths are 2.57 Å. There is one shorter (1.80 Å) and one longer (2.10 Å) Cu–N bond length. In the second Cu site, Cu is bonded in a linear geometry to four equivalent Cu and two N atoms. All Cu–Cu bond lengths are 2.70 Å. There is one shorter (1.83 Å) and one longer (1.88 Å) Cu–N bond length. In the third Cu site, Cu is bonded in a linear geometry to four equivalent Cu and two N atoms. All Cu–Cu bond lengths are 2.68 Å. There is one shorter (1.76 Å) and one longer (1.95 Å) Cu–N bond length. In the fourth Cu site, Cu is bonded in a linear geometry to four equivalent Cu and two N atoms. All Cu–Cu bond lengths are 2.75 Å. There is one shorter (1.81 Å) and one longer (1.89 Å) Cu–N bond length. In the fifth Cu site, Cu is bonded in a 1-coordinate geometry to one Pd and seven Cu atoms. There are six inequivalent N sites. In the first N site, N is bonded to two equivalent Pd and four equivalent Cu atoms to form corner-sharing NCu4Pd2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second N site, N is bonded to two equivalent Pd and four equivalent Cu atoms to form corner-sharing NCu4Pd2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third N site, N is bonded in a linear geometry to two equivalent Cu atoms. In the fourth N site, N is bonded in an octahedral geometry to six Cu atoms. In the fifth N site, N is bonded in a square co-planar geometry to four Cu atoms. In the sixth N site, N is bonded in a linear geometry to two equivalent Cu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on DyV2Fe10N by Materials Project

DyV2Fe10N crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Dy is bonded in a linear geometry to two equivalent V, ten Fe, and two equivalent N atoms. Both Dy–V bond lengths are 3.08 Å. There are two shorter (3.07 Å) and eight longer (3.25 Å) Dy–Fe bond lengths. Both Dy–N bond lengths are 2.37 Å. V is bonded in a 10-coordinate geometry to one Dy, one V, and twelve Fe atoms. The V–V bond length is 2.43 Å. There are a spread of V–Fe bond distances ranging from 2.61–2.92 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded in a single-bond geometry to two equivalent V, six Fe, and one N atom. There are four shorter (2.46 Å) and two longer (2.64 Å) Fe–Fe bond lengths. The Fe–N bond length is 1.91 Å. In the second Fe site, Fe is bonded in a single-bond geometry to two equivalent V, six Fe, and one N atom. There are four shorter (2.45 Å) and two longer (2.66 Å) Fe–Fe bond lengths. The Fe–N bond length is 1.91 Å. In the third Fe site, Fe is bonded to two equivalent Dy, two equivalent V, and eight Fe atoms to form distorted FeDy2V2Fe8 cuboctahedra that share corners with ten equivalent FeDy2V2Fe8 cuboctahedra, corners with two equivalent NDy2Fe4 octahedra, edges with four equivalent FeDy2V2Fe8 cuboctahedra, faces with six equivalent FeDy2V2Fe8 cuboctahedra, and faces with two equivalent NDy2Fe4 octahedra. The corner-sharing octahedral tilt angles are 69°. There are two shorter (2.37 Å) and two longer (2.62 Å) Fe–Fe bond lengths. In the fourth Fe site, Fe is bonded in a 2-coordinate geometry to one Dy, four equivalent V, and nine Fe atoms. The Fe–Fe bond length is 2.38 Å. N is bonded to two equivalent Dy and four Fe atoms to form NDy2Fe4 octahedra that share corners with eight equivalent FeDy2V2Fe8 cuboctahedra, corners with two equivalent NDy2Fe4 octahedra, and faces with eight equivalent FeDy2V2Fe8 cuboctahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y6Mg(SiS7)2 by Materials Project

MgY6Si2S14 crystallizes in the trigonal P3 space group. The structure is three-dimensional. Mg2+ is bonded in an octahedral geometry to six S2- atoms. There are three shorter (2.57 Å) and three longer (2.59 Å) Mg–S bond lengths. There are two inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Y–S bond distances ranging from 2.77–3.08 Å. In the second Y3+ site, Y3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Y–S bond distances ranging from 2.77–3.00 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded in a tetrahedral geometry to four S2- atoms. There are one shorter (2.10 Å) and three longer (2.14 Å) Si–S bond lengths. In the second Si4+ site, Si4+ is bonded in a tetrahedral geometry to four S2- atoms. There are one shorter (2.11 Å) and three longer (2.14 Å) Si–S bond lengths. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted tetrahedral geometry to three equivalent Y3+ and one Si4+ atom. In the second S2- site, S2- is bonded in a distorted tetrahedral geometry to three equivalent Y3+ and one Si4+ atom. In the third S2- site, S2- is bonded in a 5-coordinate geometry to one Mg2+ and four Y3+ atoms. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to one Mg2+ and four Y3+ atoms. In the fifth S2- site, S2- is bonded in a 4-coordinate geometry to three Y3+ and one Si4+ atom. In the sixth S2- site, S2- is bonded in a 4-coordinate geometry to three Y3+ and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ZnP14Pb by Materials Project

ZnPbP14 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Zn2+ is bonded in a tetrahedral geometry to four P+0.29- atoms. There are a spread of Zn–P bond distances ranging from 2.44–2.50 Å. Pb2+ is bonded in a distorted square co-planar geometry to four P+0.29- atoms. There are a spread of Pb–P bond distances ranging from 2.82–3.08 Å. There are nine inequivalent P+0.29- sites. In the first P+0.29- site, P+0.29- is bonded in a trigonal non-coplanar geometry to three P+0.29- atoms. There are a spread of P–P bond distances ranging from 2.22–2.30 Å. In the second P+0.29- site, P+0.29- is bonded to one Zn2+, one Pb2+, and two equivalent P+0.29- atoms to form distorted corner-sharing PZnP2Pb tetrahedra. In the third P+0.29- site, P+0.29- is bonded to one Zn2+, one Pb2+, and two equivalent P+0.29- atoms to form distorted corner-sharing PZnP2Pb tetrahedra. Both P–P bond lengths are 2.22 Å. In the fourth P+0.29- site, P+0.29- is bonded in a trigonal non-coplanar geometry to three P+0.29- atoms. There are two shorter (2.22 Å) and one longer (2.24 Å) P–P bond lengths. In the fifth P+0.29- site, P+0.29- is bonded in a 4-coordinate geometry to one Zn2+, one Pb2+, and two P+0.29- atoms. Both P–P bond lengths are 2.20 Å. In the sixth P+0.29- site, P+0.29- is bonded in a trigonal non-coplanar geometry to three P+0.29- atoms. The P–P bond length is 2.23 Å. In the seventh P+0.29- site, P+0.29- is bonded in a trigonal non-coplanar geometry to three P+0.29- atoms. The P–P bond length is 2.23 Å. In the eighth P+0.29- site, P+0.29- is bonded in a trigonal non-coplanar geometry to three P+0.29- atoms. In the ninth P+0.29- site, P+0.29- is bonded in a trigonal non-coplanar geometry to three P+0.29- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NdV2Fe10N by Materials Project

NdFe10V2N crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Nd is bonded in a linear geometry to two equivalent V, ten Fe, and two equivalent N atoms. Both Nd–V bond lengths are 3.09 Å. There are two shorter (3.09 Å) and eight longer (3.26 Å) Nd–Fe bond lengths. Both Nd–N bond lengths are 2.41 Å. V is bonded in a 10-coordinate geometry to one Nd, one V, and twelve Fe atoms. The V–V bond length is 2.42 Å. There are a spread of V–Fe bond distances ranging from 2.63–2.95 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded in a single-bond geometry to two equivalent V, six Fe, and one N atom. There are four shorter (2.47 Å) and two longer (2.68 Å) Fe–Fe bond lengths. The Fe–N bond length is 1.92 Å. In the second Fe site, Fe is bonded in a single-bond geometry to two equivalent V, six Fe, and one N atom. There are four shorter (2.46 Å) and two longer (2.65 Å) Fe–Fe bond lengths. The Fe–N bond length is 1.93 Å. In the third Fe site, Fe is bonded to two equivalent Nd, two equivalent V, and eight Fe atoms to form distorted FeNd2V2Fe8 cuboctahedra that share corners with ten equivalent FeNd2V2Fe8 cuboctahedra, corners with two equivalent NNd2Fe4 octahedra, edges with four equivalent FeNd2V2Fe8 cuboctahedra, faces with six equivalent FeNd2V2Fe8 cuboctahedra, and faces with two equivalent NNd2Fe4 octahedra. The corner-sharing octahedral tilt angles are 68°. There are two shorter (2.41 Å) and two longer (2.64 Å) Fe–Fe bond lengths. In the fourth Fe site, Fe is bonded in a 2-coordinate geometry to one Nd, four equivalent V, and nine Fe atoms. The Fe–Fe bond length is 2.36 Å. N is bonded to two equivalent Nd and four Fe atoms to form NNd2Fe4 octahedra that share corners with eight equivalent FeNd2V2Fe8 cuboctahedra, corners with two equivalent NNd2Fe4 octahedra, and faces with eight equivalent FeNd2V2Fe8 cuboctahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on In2Te9RuCl8 by Materials Project

RuIn2Te9Cl8 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Ru2+ is bonded in an octahedral geometry to six Te atoms. There are a spread of Ru–Te bond distances ranging from 2.67–2.69 Å. In3+ is bonded in a tetrahedral geometry to four Cl1- atoms. There are a spread of In–Cl bond distances ranging from 2.39–2.41 Å. There are five inequivalent Te sites. In the first Te site, Te is bonded in a 2-coordinate geometry to two equivalent Te and two equivalent Cl1- atoms. Both Te–Te bond lengths are 2.78 Å. Both Te–Cl bond lengths are 3.78 Å. In the second Te site, Te is bonded in a 5-coordinate geometry to one Ru2+, two Te, and two Cl1- atoms. The Te–Te bond length is 2.88 Å. There are one shorter (3.58 Å) and one longer (3.61 Å) Te–Cl bond lengths. In the third Te site, Te is bonded in a 3-coordinate geometry to one Ru2+ and two Te atoms. The Te–Te bond length is 2.78 Å. In the fourth Te site, Te is bonded in a 5-coordinate geometry to two Te and three Cl1- atoms. The Te–Te bond length is 2.78 Å. There are a spread of Te–Cl bond distances ranging from 3.23–3.63 Å. In the fifth Te site, Te is bonded in a 4-coordinate geometry to one Ru2+, two Te, and one Cl1- atom. The Te–Te bond length is 2.88 Å. The Te–Cl bond length is 3.73 Å. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted single-bond geometry to one In3+ and two Te atoms. In the second Cl1- site, Cl1- is bonded in a distorted single-bond geometry to one In3+ and three Te atoms. In the third Cl1- site, Cl1- is bonded in a distorted bent 150 degrees geometry to one In3+ and one Te atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one In3+ and one Te atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MnSb4 by Materials Project

MnSb4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Mn2+ is bonded in a linear geometry to two equivalent Sb+0.50- atoms. Both Mn–Sb bond lengths are 2.70 Å. There are two inequivalent Sb+0.50- sites. In the first Sb+0.50- site, Sb+0.50- is bonded in a distorted single-bond geometry to one Mn2+ and one Sb+0.50- atom. The Sb–Sb bond length is 3.29 Å. In the second Sb+0.50- site, Sb+0.50- is bonded to six Sb+0.50- atoms to form a mixture of edge and corner-sharing SbSb6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are one shorter (3.02 Å) and four longer (3.08 Å) Sb–Sb bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeAg3F6 by Materials Project

FeAg3F6 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Fe3+ is bonded in an octahedral geometry to six F1- atoms. There is four shorter (1.95 Å) and two longer (1.96 Å) Fe–F bond length. There are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 8-coordinate geometry to four equivalent F1- atoms. All Ag–F bond lengths are 2.42 Å. In the second Ag1+ site, Ag1+ is bonded in a linear geometry to two equivalent F1- atoms. Both Ag–F bond lengths are 2.11 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to one Fe3+ and two equivalent Ag1+ atoms. In the second F1- site, F1- is bonded in a linear geometry to one Fe3+ and one Ag1+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS2024

X-57 Maxwell Vehicle Geometry Document ANLYS-CEPT-002 Rev C

This report documents the two primary coordinate systems used on the X-57 project and their relationship. The coordinate systems (CS) are the Tecnam OEM CS and the X-57 Project CS. All project measurements, unless noted, are taken from the X-57 Project CS. Also, other important locations on the COTS aircraft and the X-57 composite wing are noted and documented. This report also documents the X-57 wing baseline location and other important geometric aspects of the wing. All dimensions are in inches unless otherwise noted.

Edward J Nemie↗
NASA NTRS1997

An Accurate and Dynamic Computer Graphics Muscle Model

A computer based musculo-skeletal model was developed at the University in the departments of Mechanical and Biomedical Engineering. This model accurately represents human shoulder kinematics. The result of this model is the graphical display of bones moving through an appropriate range of motion based on inputs of EMGs and external forces. The need existed to incorporate a geometric muscle model in the larger musculo-skeletal model. Previous muscle models did not accurately represent muscle geometries, nor did they account for the kinematics of tendons. This thesis covers the creation of a new muscle model for use in the above musculo-skeletal model. This muscle model was based on anatomical data from the Visible Human Project (VHP) cadaver study. Two-dimensional digital images from the VHP were analyzed and reconstructed to recreate the three-dimensional muscle geometries. The recreated geometries were smoothed, reduced, and sliced to form data files defining the surfaces of each muscle. The muscle modeling function opened these files during run-time and recreated the muscle surface. The modeling function applied constant volume limitations to the muscle and constant geometry limitations to the tendons.

Levine, David Asher↗
NASA NTRS2016

Human Exploration System Test-Bed for Integration and Advancement (HESTIA) Support of Future NASA Deep-Space Missions

The Engineering Directorate at the NASA - Johnson Space Center is outfitting a 20-Foot diameter hypobaric chamber in Building 7 to support future deep-space Environmental Control & Life Support System (ECLSS) research as part of the Human Exploration System Test-bed for Integration and Advancement (HESTIA) Project. This human-rated chamber is the only NASA facility that has the unique experience, chamber geometry, infrastructure, and support systems capable of conducting this research. The chamber was used to support Gemini, Apollo, and SkyLab Missions. More recently, it was used to conduct 30-, 60-, and 90-day human ECLSS closed-loop testing in the 1990s to support the International Space Station and life support technology development. NASA studies show that both planetary surface and deep-space transit crew habitats will be 3-4 story cylindrical structures driven by human occupancy volumetric needs and launch vehicle constraints. The HESTIA facility offers a 3-story, 20-foot diameter habitat consistent with the studies' recommendations. HESTIA operations follow stringent processes by a certified test team that including human testing. Project management, analysis, design, acquisition, fabrication, assembly and certification of facility build-ups are available to support this research. HESTIA offers close proximity to key stakeholders including astronauts, Human Research Program (who direct space human research for the agency), Mission Operations, Safety & Mission Assurance, and Engineering Directorate. The HESTIA chamber can operate at reduced pressure and elevated oxygen environments including those proposed for deep-space exploration. Data acquisition, power, fluids and other facility resources are available to support a wide range of research. Recently completed HESTIA research consisted of unmanned testing of ECLSS technologies. Eventually, the HESTIA research will include humans for extended durations at reduced pressure and elevated oxygen to demonstrate very high reliability of critical ECLSS and other technologies.

Marmolejo, Jose↗
DOE OSTI2025

Software For Advanced Large-scale Analysis Of Magnetic Confinement For Numerical Design, Engineering & Research (salamander)

As magnetic confinement fusion energy gains traction internationally to enable abundant energy production, designing components for fusion systems is a pressing challenge. During the planned lifetime of a fusion device, components evolve in extreme environments and must withstand large, repeated thermal loads and bombardment by 14 MeV neutrons, plasma ions, and neutral particles (deuterium, tritium, and helium), corrosive conditions, etc. All these physical processes take place simultaneously, interact in intricate ways, and impose important constraints that can affect performance. Experimental data is rare and costly to obtain, making design particularly challenging. Predictive computational frameworks must be an integral part of an accelerated and cost-effective design process by modeling fusion system performance in simulated environments. To better understand component degradation and operational impacts on their performance, the Software for Advanced Large-scale Analysis of MAgnetic confinement for Numerical Design, Engineering & Research (SALAMANDER) is designed as an open-source, fully integrated, multiphysics, multiscale, NQA-1 compliant framework facilitating 3D, high-fidelity fusion system modeling. To that end, SALAMANDER is a MOOSE-based framework, and therefore leverages MOOSE upstream libraries such as PETSc and libMesh to deliver sophisticated finite element, finite volume, and nonlinear solver technology for fusion energy simulations. SALAMANDER couples MOOSE physics module capabilities—such as thermal hydraulics, heat conduction, Navier-Stokes, and thermomechanics—with tritium transport via TMAP8, neutronics via Cardinal, and nascent particle-in-cell capabilities. Direct simulation Monte Carlo methods will be used to address neutral transport near the walls. By coupling all these physics in an integrated application, SALAMANDER will enable high-fidelity modeling of irradiation levels and plasma exposure conditions of plasma facing components and their impact on heat and tritium distributions, as well as the resulting mechanical constraints experienced by the plasma facing components and performance of blanket systems. Furthermore, SALAMANDER will be particularly suited for engineering studies thanks to the stochastic tool module readily available in MOOSE, allowing for extended uncertainty quantification and risk analysis studies. It is also able to use computer-aided design (CAD) meshes to model complex geometries, which is indispensable for fusion systems. SALAMANDER therefore supports design, safety, engineering, and research projects for magnetic confinement fusion systems

Simon, Pierre-Clement [Idaho National Laboratory (↗
NASA NTRS1995

SAR investigations of glaciers in northwestern North America

The objective of this project was to investigate the utility of satellite synthetic aperture radar (SAR) imagery for measurement of geophysical parameters on Alaskan glaciers relevant to their mass balance and dynamics, including: (1) the positions of firn lines (late-summer snow lines); (2) surface velocities on fast-flowing (surging) glaciers, and also on slower steady-flow glaciers; and (3) the positions and changes in the positions of glacier termini. Preliminary studies of topography and glacier surface velocity with SAR interferometry have also been carried out. This project was motivated by the relationships of multi-year to decadal changes in glacier geometry to changing climate, and the probable significant contribution of Alaskan glaciers to rising sea level.

Lingle, Craig S.↗
NASA NTRS1999

Bone Blood Flow During Simulated Microgravity: Physiological and Molecular Mechanisms

Blood flow to bone has been shown to affect bone mass and presumably bone strength. Preliminary data indicate that blood flow to the rat femur decreases after 14 days of simulated microgravity, using hindlimb suspension (HLS). If adult rats subjected to HLS are given dobutamine, a synthetic catecholamine which can cause peripheral vasodilation and increased blood flow, the loss of cortical bone area usually observed is prevented. Further, mechanisms exist at the molecular level to link changes in bone blood flow to changes in bone cell activity, particularly for vasoactive agents like nitric oxide (NO). The decreases in fluid shear stress created by fluid flow associated with the shifts of plasma volume during microgravity may result in alterations in expression of vasoactive agents such as NO, producing important functional effects on bone cells. The primary aim of this project is to characterize changes in 1) bone blood flow, 2) indices of bone mass, geometry, and strength, and 3) changes in gene expression for modulators of nitric oxide activity (e.g., nitric oxide synthase) and other candidate genes involved in signal transduction of mechanical loading after 3, 7, 14, 21, and 28 days of HLS in the adult rat. Using a rat of at least 5 months of age avoids inadvertently studying effects of simulated microgravity on growing, rather than adult, bone. Utilizing the results of these studies, we will then define how altered blood flow contributes to changes in bone with simulated microgravity by administering a vasodilatory agent (which increases blood flow to tissues) during hindlimb suspension. In all studies, responses in the unloaded hindlimb bones (tibial shaft, femoral neck) will be compared with those in the weightbearing humeral shaft and the non-weightbearing calvarium (skull) from the same animal. Bone volumetric mineral density and geometry will be quantified by peripheral quantitative CT; structural and material properties of the long bones will be determined by 3-point bending (tibia, humerus) or compression (femoral neck) testing to failure. A unique aspect of these studies will be defining the time course of changes in gene expression in bone cell populations with unloading, accomplished with Northern blots, in situ hybridization, and immunohistochemistry. These studies have high relevance for concurrent protocols being proposed by investigators on NSBRI Cardiovascular and Muscle teams, with blood flow data available on a number of tissues other than bone. Further, dobutamine and other Beta-agonists have been tested as countermeasures for altered muscle and cardiovascular function. Results of the intervention tested in our studies have potential relevance for a number of systemic changes seen with prolonged spaceflight.

Bloomfield, Susan A.↗
NASA NTRS2001

Helioseismic Holography and a Study of the Process of Magnetic Flux Disappearance in Canceling Bipoles

Project 1: We have developed and applied a technique of helioseismic holography along the lines of originally set out in our proposal. The result of the application of this diagnostic technique to solar activity and the quiet Sun has produced a number of important discoveries: (1) acoustic moats surrounding sunspots; (2) acoustic glories surround large active regions; (3) acoustic condensations beneath active regions; and (4) temporally-resolve acoustic images of a solar flare. These results have been published in a series of papers in the Astrophysical Journal. We think that helioseismic holography is now established as the most powerful and discriminating diagnostic in local helioseismology. Project 2: We conducted a collaborative observational program to define the physical character and magnetic geometry of canceling magnetic bipoles aimed at determining if the cancellation process is the result of submergence of magnetic fields. This assessment is based on ground-based observations combining photospheric and chromospheric magnetograms from NSO/KP, BBSO, and SOHO-MDI, and EUV and X-ray images from SOHO EIT/CDS, Yohkoh/SXT, and TRACE. Our study involves the analysis of data taken during three observing campaigns to define the height structure of canceling bipoles inferred from magnetic field and intensity images, and how this varies with time. We find that some canceling bipoles can be explained by the submerge of their magnetic flux. A paper on the results of this analysis will be presented at an upcoming scientific meeting and be written up for publication.

Lindsey, Charles↗
NASA NTRS2010

Analysis of a Channeled Centerbody Supersonic Inlet for F-15B Flight Research

The Propulsion Flight Test Fixture at the NASA Dryden Flight Research Center is a unique test platform available for use on the NASA F-15B airplane, tail number 836, as a modular host for a variety of aerodynamics and propulsion research. The first experiment that is to be flown on the test fixture is the Channeled Centerbody Inlet Experiment. The objectives of this project at Dryden are twofold: 1) flight evaluation of an innovative new approach to variable geometry for high-speed inlets, and 2) flight validation of channeled inlet performance prediction by complex computational fluid dynamics codes. The inlet itself is a fixed-geometry version of a mixed-compression, variable-geometry, supersonic in- let developed by TechLand Research, Inc. (North Olmsted, Ohio) to improve the efficiency of supersonic flight at off-nominal conditions. The concept utilizes variable channels in the centerbody section to vary the mass flow of the inlet, enabling efficient operation at a range of flight conditions. This study is particularly concerned with the starting characteristics of the inlet. Computational fluid dynamics studies were shown to align well with analytical predictions, showing the inlet to remain unstarted as designed at the primary test point of Mach 1.5 at an equivalent pressure altitude of 29,500 ft local conditions. Mass-flow-related concerns such as the inlet start problem, as well as inlet efficiency in terms of total pressure loss, are assessed using the flight test geometry.

Ratnayake, Nalin A.↗
NASA NTRSDate not supplied

Pterodactyl: Thermal Protection System Design Methodology for a Flap Control System

As interest in non-traditional entry vehicles continues to grow, the need for a Thermal Protection System (TPS) analysis approach that can account for entry solutions with changing geometry and complicated flow dynamics becomes invaluable. The NASA Space Technology Mission Directorate (STMD) Pterodactyl project aims to accomplish this through examination of a flap controlled Adaptable, Deployable Entry Placement Technology (ADEPT)-style Deployable Entry Vehicle (DEV). This paper details an improved methodology for modeling the aerothermodynamic environment and initial TPS design for a flap control system integrated with a symmetric DEV. Improvements include i) the addition of an anchoring process that uses an increased fidelity aerodynamic solution to anchor the aerothermal environment predictions and ii) increased surface resolution, for the 1D heat transfer analysis, to isolate the hottest area on the flap that will require the thickest TPS. It was found that the anchoring process provided an improved aerothermal environment prediction. Additionally, this analysis demonstrated that there is a need for increased surface resolution in the 1D thermal analysis since the predicted location of the hottest point was significantly different than the location identified using very coarse surface resolution.

Zane B Hays↗
NASA NTRS1987

Geometric description and grid generation for space vehicles

The understanding and analysis of three dimensional fluid behavior around reentry vehicles, like the Space Shuttle Orbiter, is of considerable importance for flight applications. Vehicle designers need pressure, heat transfer, and shear distributions to support design activities. Traditionally these have been obtained by experimental data. Significant reduction in design costs can be obtained if the calculated results based on finite difference procedures are used to verify and supplement experimental results. Computing the flow field over Space Shuttle Orbiter, which has complex cross sectional geometries is a major problem. A first step in this direction is development of body definition and grid generation procedure. In this project a digitized body definition and grid generation procedure, developed earlier at JSC, is modified and applied to the Shuttle Orbiter X24C-10D. Two dimensional grid and body definition for various sections of the space vehicle is obtained using the differential equation method. This study demonstrates that this geometry and grid generation procedure can be applied to other aerospace vehicles such as aerospaceplanes.

Krishna, Madakasira G.↗