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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS2020

An Ultra-long Life, High-performance, Flexible Li-CO2Battery Based on Multifunctional Carbon Electrocatalysts

Integrating CO2 utilization and renewable energy delivery/storage, the rechargeable Li–CO2 battery has been considered as a promising candidate for next-generation secondary batteries. However, high-performance catalyst(s) for efficient formation and decomposition of the discharge product, Li2CO3, are an imperative part of a Li–CO2 battery. The development of flexible Li–CO2 batteries extends their applications into compliant and wearable devices/systems, but at the same time imposes a big challenge for battery fabrication and lifetime enhancement. In this study, a rechargeable quasi-solidus flexible Li–CO2 battery was designed and fabricated using highly active N,S-doped carbon nanotubes (N,S-doped CNTs) as the cathode catalyst, and a smart polymer gel as the flexible electrolyte. This newly-developed flexible Li–CO2 battery exhibited a capacity as high as 23560 mAh g−1 based on the catalyst mass and an ultra-long lifetime of up to 538 cycles with excellent mechanical flexibility. This work provides a platform for the design and development of high-performance flexible Li–CO2 batteries from low-cost, earth-abundant, carbon-based multifunctional cathode catalysts.

Superior stability↗
NASA NTRS1995

Wing-section optimization for supersonic viscous flows

The recent interest in High Speed Civil Transport (HSCT) has resulted in renewed research studies of optimized supersonic cruise transport configurations. Incorporation of flow viscosity effects in the design process of such a supersonic wing is currently under investigation. This may lead to more accurate problem formulations and, in turn, greater aerodynamic efficiency than can be obtained by the traditional, inviscid, linear theories. In this context, for a design code to be a candidate for a complex optimization problem, such as three-dimensional viscous supersonic wing design, it should be validated using simpler building-block shapes. To optimize the shape of a supersonic wing, an automated method that also includes higher fidelity to the flow physics is desirable. With this impetus, an aerodynamic optimization methodology incorporating Navier-Stokes equations and sensitivity analysis had been previously developed. Prior to embarking upon the wing design task, the present investigation concentrated on testing the flexibility of the methodology, and the identification of adequate problem formulations, by defining two-dimensional, cost-effective test cases. Starting with two distinctly different initial airfoils, two independent shape optimizations resulted in shapes with very similar features. Secondly, the normal section to the subsonic portion of the leading edge, which had a high normal angle-of-attack, was considered. The optimization resulted in a shape with twist and camber, which eliminated the adverse pressure gradient, hence, exploiting the leading-edge thrust. The wing section shapes obtained in all the test cases had the features predicted by previous studies. Therefore, it was concluded that the flowfield analyses and the sensitivity coefficients were computed and fed to the present gradient-based optimizer correctly. Also, as a result of the present two-dimensional study, suggestions were made for problem formulations which should contribute to an effective wing shape optimization.

Item, Cem C.↗
NASA NTRS1998

The Shergottite Age Paradox and the Relative Probabilities of Ejecting Martian Meteorites of Differing Ages

The apparent paradox that the majority of impacts yielding Martian meteorites appear to have taken place on only a few percent of the Martian surface can be resolved if all the shergottites were ejected in a single event rather than in multiple events as expected from variations in their cosmic ray exposure and crystallization ages. If the shergottite-ejection event is assigned to one of three craters in the vicinity of Olympus Mons that were previously identified as candidate source craters for the SNC (Shergottites, Nakhlites, Chassigny) meteorites, and the nakhlite event to another candidate crater in the vicinity of Ceraunius Tholus, the implied ages of the surrounding terranes agree well with crater density ages. EN,en for high cratering rates (minimum ages), the likely origin of the shergottites is in the Tharsis region, and the paradox of too many meteorites from too little terrane remains for multiple shergottite-ejection events. However, for high cratering rates it is possible to consider sources for the nakhlltes which are away from the Tharsis region. The meteorite-yielding impacts may have been widely dispersed with sources of the young SNC meteorites in the northern plains, and the source of the ancient orthopyroxenite, ALH84001, in the ancient southern uplands. Oblique-impact craters can be identified with the sources of the nakhlites and the orthopyroxenite,, respectively, in the nominal cratering rate model, and with the shergottites and orthopyroxenite, respectively, in the high cratering rate model. Thus, oblique impacts deserve renewed attention as an ejection mechanism for Martian meteorites.

Borg, L. E.↗
NASA NTRS2020

University of Maryland Minimum Crew Cabin Studies ENAE484 X-Hab Final Report

With renewed interest in human spaceflight, and the astronomically high cost to send things into space, NASA is looking into methods for minimizing all aspects of crewed flight. While maintaining a crew of at least two to four people, there are considerations into duration, habitat size, habitat orientation, and many other factors to try and get the most science, safely, for the least amount of money. From these constraints, the class' project was organized. The topic of "Minimum Crew Cabin Sizing" was chosen, with a plan to do experimentation to verify or update some of the volumetric models for various activities. The actual crew cabin itself is something that can easily alter the mass, cost, and development time. In trying to quantify how small is too small { or what can be made smaller { programs can save money, time, and mass with an appropriately sized minimum volume habitat.

David Lee Akin↗
NASA NTRS2022

Contribution of Spicules to Solar Coronal Emission

Recent high-resolution imaging and spectroscopic observations have generated renewed interest in spicules' role in explaining the hot corona. Some studies suggest that some spicules, often classified as type II, may provide significant mass and energy to the corona. Here we use numerical simulations to investigate whether such spicules can produce the observed coronal emission without any additional coronal heating agent. Model spicules consisting of a cold body and hot tip are injected into the base of a warm (0.5 MK) equilibrium loop with different tip temperatures and injection velocities. Both piston- and pressure-driven shocks are produced. We find that the hot tip cools rapidly and disappears from coronal emission lines such as Fe xii 195 and Fe xiv 274. Prolonged hot emission is produced by preexisting loop material heated by the shock and by thermal conduction from the shock. However, the shapes and Doppler shifts of synthetic line profiles show significant discrepancies with observations. Furthermore, spatially and temporally averaged intensities are extremely low, suggesting that if the observed intensities from the quiet Sun and active regions were solely due to type II spicules, one to several orders of magnitude more spicules would be required than have been reported in the literature. This conclusion applies strictly to the ejected spicular material. We make no claims about emissions connected with waves or coronal currents that may be generated during the ejection process and heat the surrounding area.

Shanwlee Sow Mondal↗
NASA NTRS2011

Environmental Signatures for Habitability: What to Measure and How to Rank the Habitability Potential of Mars

The environmental signatures for habitability are not necessarily biosignatures, even though on Earth, they are definitive proof of habitability. It is the constant overprint of the chemical signatures of life that makes it difficult to recognize the chemical and physical properties of a potentially habitable environment as distinct from an inhabited one. Mars Science Laboratory (MSL) will soon embark on a mission to Mars to assess its past or present habitability, so it is useful to examine how we measure habitability on Earth and prepare for how that approach may differ for Mars. This exercise includes: (a) articulation of fundamental assumptions about habitability, (b) an inventory of factors that affect habitability, (c) development of metrics, measurement approach and implementation, and (d) a new classification scheme for planetary habitability that goes beyond the binary "yes" or "no." There may be dozens of factors that affect habitability and they can be weighted as a function of specific environment. However a robotic, in situ investigation even on Earth has constraints that prevent the measurement of every environmental factor, so metrics must be reduced to the most relevant subset, given available time, cost, technical feasibility and scientific importance. Many of the factors could be measured with a combination of orbital data and the MSL payload. We propose that, at a minimum, a designation of high habitability potential requires the following conditions be met: (a) thermally stable with respect to extremes and frequency of fluctuation, (b) has more than one energy source, (c) sufficient chemical diversity to make compounds with covalent and hydrogen bonding, (d) can moderate ionizing radiation enough to allow a stable or evolving pool of organic molecules, (e) must have water or other high quality polar solvent, (f) must be able to renew chemical resources (e.g., plate tectonics, volcanism or something else we haven't envisioned). A measurement approach we have taken to measure habitability on Earth is : 1. Study remote sensing data, maps, etc. 2. Decide how big an area to measure. 3. Determine the spatial sampling rate. 4. Determine the temporal sampling rate. 5. Determine the order of measurements 6. Decide where to begin measurements 7. Select locations at field site and proceed While science drives each of the steps, there are additional constraints, e.g., technical, time, cost, safety (risk). This approach is also executable on Mars. Measurement of past habitability is more challenging both for Earth and Mars where access to the past means subsurface access and confrontation with unknowns about preservation of the martian past. Some environments preserve evidence of past habitability better than others, and this is where selection of the landing site to maximize the preservation potential of habitability indicators will be key. Mars presents an opportunity to discover transitional states between habitable or not, and we offer a ranking scale for planetary habitability with Mars as the second test subject: CLASS ONE Uninhabitable and likely has never been so CLASS TWO Has a high potential but no confirmed observation of life (as defined above) CLASS THREE Inhabited (we find life) 3-A Globally inhabited 3-B Primitive life; early in its evolution, but not yet globally established 3-C Exists only in refugia -- planet heading toward class four CLASS FOUR Post-habitable (there once was life, but now it's gone) MSL provides an opportunity to carefully investigate the habitability of at least one site on Mars and it will reveal much about the possible states of planetary habitability

Conrad, Pamela G.↗
NASA NTRS1986

Wind tunnel wall interference

About a decade ago, interest in alleviating wind tunnel wall interference was renewed by advances in computational aerodynamics, concepts of adaptive test section walls, and plans for high Reynolds number transonic test facilities. Selection of NASA Langley cryogenic concept for the National Transonic Facility (NTF) tended to focus the renewed wall interference efforts. A brief overview and current status of some Langley sponsored transonic wind tunnel wall interference research are presented. Included are continuing efforts in basic wall flow studies, wall interference assessment/correction procedures, and adaptive wall technology.

Newman, Perry A.↗
NASA NTRS2001

Practicality of Using a Tether for Electrodynamic Reboost of the International Space Station

ElectroDynamic (ED) Tethers can generate continuous low thrust in a low Earth orbit. An induced current running through the length of the tether reacts with the geomagnetic field to produce thrust. The amount of thrust scales with tether lens!th and current. The International Space Station (ISS) requires periodic reboost to maintain an approximately circular orbit t above the Earth. The baseline reboost method is a traditional bi-propellant rocket thruster and tankage system which must to be refueled via Soyuz / Progress or other launch vehicle. The estimated propellant costs associated with keeping ISS in the designated orbit over a 10-year life have been extremely high. The ED Tether would draw energy from the renewable ISS Solar Array electrical power system. Propulsion requirements for ISS vary depending on solar wind and other conditions. It is projected that a ED Tether could provide the majority of the required reboost thrust for ISS for a nominal solar year. For above nominal solar wind years the ISS would have to use the rocket reboost system, but at a greatly reduced level. Thus resulting in substantial cost savings, via the reduction in the number of Earth-to-orbit launch vehicle flights to the ISS that must bring reboost propellant. However, the purposes of this paper is to further Previous research on an ISS ED Tether and examine the operational and technical issues working against using a ED Tether on ISS. Issues such as Shuttle rendezvous and flight path concerns raise serious safety concerns and restrictions on tether use. Tether issues such as tether librations and off angle thrust raise concerns about impacts to microgravity payloads and the long-term effect on ISS orbital path and inclination. Operational issues such as peak power available to an ED Tether and allowable duty cycle may impose severe restrictions on tether design and ultimately limit the practicality of an ED Tether on ISS. Thus while at first glance the cost numbers appear to be strongly in favor of an ED Tether the limitations imposed by safety, operations and technical concerns may severely undermine the economic model. Possible Solutions to these problems have been investigated and proposed, however some items like off angle thrust are still being actively investigated for an adequate solution.

Blumer, J. H.↗
NASA NTRS1985

SONTRAC: A solar neutron track chamber detector

The recent detection on the solar maximum mission (SMM) satellite of high energy neutrons emitted during large solar flares has provided renewed incentive to design a neutron detector which has the sensitivity, energy resolution, and time resolution to measure the neutron time and energy spectra with sufficient precision to improve our understanding of the basic flare processes. Over the past two decades a variety of neutron detectors has been flown to measure the atmospheric neutron intensity above 10 MeV and to search for solar neutrons. The SONTRAC (Solar Neutron Track Chamber) detector, a new type of neutron detector which utilizes n-p scattering and has a sensitivity 1-3 orders of magnitude greater than previous instruments in the 20-200 MeV range is described. The energy resolution is 1% for neutron kinetic energy, T sub n 50 MeV. When used with a coded aperture mask at 50 m (as would be possible on the space station) an angular resolution of approx. 4 arc sec could be achieved, thereby locating the sites of high energy nuclear interactions with an angular precision comparable to the existing x-ray experiments on SMM. The scintillation chamber is investigated as a track chamber for high energy physics, either by using arrays of scintillating optical fibers or by optical imaging of particle trajectories in a block of scintillator.

Frye, G. M., Jr.↗
NASA NTRS2007

Hydrogen Generation Through Renewable Energy Sources at the NASA Glenn Research Center

An evaluation of the potential for generating high pressure, high purity hydrogen at the NASA Glenn Research Center (GRC) was performed. This evaluation was based on producing hydrogen utilizing a prototype Hamilton Standard electrolyzer that is capable of producing hydrogen at 3000 psi. The present state of the electrolyzer system was determined to identify the refurbishment requirements. The power for operating the electrolyzer would be produced through renewable power sources. Both wind and solar were considered in the analysis. The solar power production capability was based on the existing solar array field located at NASA GRC. The refurbishment and upgrade potential of the array field was determined and the array output was analyzed with various levels of upgrades throughout the year. The total available monthly and yearly energy from the array was determined. A wind turbine was also sized for operation. This sizing evaluated the wind potential at the site and produced an operational design point for the wind turbine. Commercially available wind turbines were evaluated to determine their applicability to this site. The system installation and power integration were also addressed. This included items such as housing the electrolyzer, power management, water supply, gas storage, cooling and hydrogen dispensing.

Colozza, Anthony↗
NASA NTRS1978

Airborne photometric observations between 1.25 and 3.25 microns of late-type stars

The stars Alpha Aur (G5 III + G0 III), Alpha Boo (K2 IIIp), Alpha Ori (M1-M2 Ia-Ib), Alpha Sco (M1.5 Iab), Mu Gem (M3 III), and Alpha Her (M5 Ib-II) have been observed using interference filters in five photometric bands between 1.25 and 3.25 microns during seven flights with NASA's Lear Jet Infrared Observatory. The filters were designed to measure molecular features, primarily from CN and CO, and continuum fluxes. By calibrating the photometer in the laboratory against a stabilized blackbody source, relative flux curves have been derived. The energy distributions and the strength of molecular features are discussed. The most interesting result obtained is that the fluxes from Mu Gem and Alpha Her in the filter centered at 3.25 microns seem to be depressed by at least some tenths of a magnitude. Tentatively this depression is proposed to be due to the wings of the two vibration-rotation bands (about 2.7 microns) of hot water vapor. Since water vapor is an important opacity source and its abundance is a sensitive C/O indicator, the proposed interpretation makes renewed efforts to detect water bands in early M stars highly desirable.

Nordh, H. L.↗
NASA NTRS1981

Fresnel concentrating collector

An advanced point focusing solar technology demonstrated potential for near term commercialization as a renewable energy technology. The design features combine to produce a highly efficient, low cost, safe, adaptable, durable system which is simple to manufacture, install and maintain.

Rogers, W.↗
NASA NTRS1996

Propellant Chemistry for CFD Applications

Current concepts for reusable launch vehicle design have created renewed interest in the use of RP-1 fuels for high pressure and tri-propellant propulsion systems. Such designs require the use of an analytical technology that accurately accounts for the effects of real fluid properties, combustion of large hydrocarbon fuel modules, and the possibility of soot formation. These effects are inadequately treated in current computational fluid dynamic (CFD) codes used for propulsion system analyses. The objective of this investigation is to provide an accurate analytical description of hydrocarbon combustion thermodynamics and kinetics that is sufficiently computationally efficient to be a practical design tool when used with CFD codes such as the FDNS code. A rigorous description of real fluid properties for RP-1 and its combustion products will be derived from the literature and from experiments conducted in this investigation. Upon the establishment of such a description, the fluid description will be simplified by using the minimum of empiricism necessary to maintain accurate combustion analyses and including such empirical models into an appropriate CFD code. An additional benefit of this approach is that the real fluid properties analysis simplifies the introduction of the effects of droplet sprays into the combustion model. Typical species compositions of RP-1 have been identified, surrogate fuels have been established for analyses, and combustion and sooting reaction kinetics models have been developed. Methods for predicting the necessary real fluid properties have been developed and essential experiments have been designed. Verification studies are in progress, and preliminary results from these studies will be presented. The approach has been determined to be feasible, and upon its completion the required methodology for accurate performance and heat transfer CFD analyses for high pressure, tri-propellant propulsion systems will be available.

Farmer, R. C.↗
NASA NTRS2000

Validated Feasibility Study of Integrally Stiffened Metallic Fuselage Panels for Reducing Manufacturing Costs

The continual need to reduce airframe cost and the emergence of high speed machining and other manufacturing technologies has brought about a renewed interest in large-scale integral structures for aircraft applications. Applications have been inhibited, however, because of the need to demonstrate damage tolerance, and by cost and manufacturing risks associated with the size and complexity of the parts. The Integral Airframe Structures (IAS) Program identified a feasible integrally stiffened fuselage concept and evaluated performance and manufacturing cost compared to conventional designs. An integral skin/stiffener concept was produced both by plate hog-out and near-net extrusion. Alloys evaluated included 7050-T7451 plate, 7050-T74511 extrusion, 6013-T6511 extrusion, and 7475-T7351 plate. Mechanical properties, structural details, and joint performance were evaluated as well as repair, static compression, and two-bay crack residual strength panels. Crack turning behavior was characterized through panel tests and improved methods for predicting crack turning were developed. Manufacturing cost was evaluated using COSTRAN. A hybrid design, made from high-speed machined extruded frames that are mechanically fastened to high-speed machined plate skin/stringer panels, was identified as the most cost-effective manufacturing solution. Recurring labor and material costs of the hybrid design are up to 61 percent less than the current technology baseline.

Pettit, R. G.↗
NASA NTRS2004

Modelling and Analysis of a Regenerative Fuel Cell Propulsion System for a High Altitude Long Endurance UAV

In the search to bridge current gaps in surveillance and communication technologies, a new type of, aircraft is currently undergoing design. The idea of a High Altitude Long Endurance (HALE) aircraft is already a few decades old, but has only recently become realizable. A relay and collector of information at altitudes of 65,000 feet and higher could greatly improve standards of data exchange, homeland security, and research of the air, land and sea. NASA, as a major force in propulsion research, is exploring methods of powering an autonomous aircraft for days, weeks, or even months without refueling. Such a task requires not only high energy density, but also the ability to make use of renewable energy sources to regenerate power. Hydrogen is one of the most energy dense fuels available. Fuel cells make use of hydrogen by harnessing the energy released as it combines with oxygen to produce electricity and water. Fuel cells are envisioned to occupy future propulsion systems in cooperation with solar cells where the photovoltaic arrays harness sunlight into power which can electrolize the water byproduct into reusable hydrogen and oxygen. Modeling this type of system requires adequate assumptions of support hardware and daily transients in operation. The performance of a regenerative fuel cell propulsion system lies in the flight characteristics (altitude, density, temperature, latitude, etc.). Each subsystem is defined by many parameters which can be varied across wide ranges. Statistical and probabilistic analyses bring forward a wealth of information that can be utilized in the design process. This is necessary since the required technologies are relatively young and barely, if yet, capable. Once the modeling is complete, a design space exploration of this highly constrained scenario can be utilized to find the optimal design. The model will become an interactive environment with which experiments and tests can be run. When linked

Simpson, Mike B.↗
NASA NTRS2004

Plasma Propulsion Research at NASA Marshall Space Flight Center

The Propulsion Research Center at NASA Marshall Space Flight Center is pursuing a range of research efforts aimed at identifying and developing new technologies for primary spacecraft propulsion. Efficient high-power electric propulsion (Ep) thrusters are a particular area of emphasis; these would enable the relatively rapid transit of large payloads about the solar system for unmanned or manned science and exploration. Such a mission would make heavy demands on the propulsion system, which may be required to run reliably for several years at a specific impulse approaching 10,OOO s with an efficiency of turning electrical power into jet power of at least 70%. The transit time to a destination scales approximately inversely with the cube root of the specific power, which is the ratio of jet power to power-plant mass. Consequently, reducing a trip time by half requires roughly an eight-fold increase in specific power. Given a renewed NASA commitment to space nuclear power, developing efficient EP thrusters with high jet power (> 100 kW) would seem to provide the most direct means of significantly increasing the specific power and hence reducing trip times. In particular, electromagnetic devices, with their high inherent thrust densities, should be better suited to high power applications than thrusters which depend exclusively on electrostatic forces for propellant acceleration.

Sheehy, Jeffrey A.↗
NASA NTRS1985

Cosmic ray He-3 measurements

The rare isotopes H-2 and He-3 in cosmic rays are believed to be of secondary origin produced by nuclear interactions of primary H-1 and He-4 with the interstellar medium. There has recently been renewed interest in these isotopes as a result of indications from high energy antiproton, positron, and He-3 observations that the origin of some primary H and He nuclei may differ from that of heavier cosmic rays. A new observation of low energy He-3 is examined. Previously reported He-3 and He-4 measurements at both low and high energies are examined and compared with calculations of the expected He-3 and He-4 ratio at 1 AU. No evidence for an excess of low energy He-3 such as that reported at high energies was found.

Mewaldt, R. A.↗
NASA NTRS1990

Hypersonic propulsion: Status and challenge

Scientists in the U.S. are again focusing on the challenge of hypersonic flight with the proposed National Aerospace Plane (NASP). This renewed interest has led to an expansion of research related to high speed airbreathing propulsion, in particular, the supersonic combustion ramjet, or scramjet. The history is briefly traced of scramjet research in the U.S., with emphasis on NASA sponsored efforts, from the Hypersonic Research Engine (HRE) to the current status of today's airframe integrated scramjets. The challenges of scramjet technology development from takeover to orbital speeds are outlined. Existing scramjet test facilities such as NASA Langley's Scramjet Test Complex as well as new high Mach number pulse facilities are discussed. The important partnership role of experimental methods and computational fluid dynamics is emphasized for the successful design of single stage to orbit vehicles.

Guy, R. Wayne↗