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At least 973 records · Page 54
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

(Invited) All-Solid-State Batteries Using Li 7 La 3 Zr 2 O 12 Garnet Electrolyte Framework

All-solid-state batteries (ASSB) using LLZO (variants of Li 7 La 3 Zr 2 O 12 ) garnet solid electrolyte with lithium metal anode potentially offer higher energy density and improved safety. Rational design of cell architecture as well as manufacturing scalability are key aspects to consider as the technology readiness level advances. A thick composite cathode layer attached to a thin solid electrolyte layer is desirable to obtain superior energy densities. Furthermore, the architecture within the composite cathode may be engineered to contain directional conduction paths of lithium ions or electrons for enhanced rate capabilities. Here, we demonstrate a functioning bulk-type LLZO based all-solid-state battery with a practical form factor incorporating the above described design concepts. Freeze-tape-casting (FTC), a scalable and environmentally friendly ceramic processing method, is used to construct 3D porous LLZO scaffolds composed of vertical arrays of LLZO walls. The thin solid-electrolyte layer is fabricated by tape-casting (TC). By sintering the stacks of FTC and TC green tapes, porous/dense bilayers and porous/dense/porous trilayers of LLZO frameworks are obtained. An ASSB was constructed using a porous/dense bilayer by infiltrating LiNi 0.6 Mn 0.2 Co 0.2 O 2 cathode powder and carbon black into the porous layer and adhering lithium metal foil to the dense side. We find it crucial to introduce a plastic crystal based soft solid electrolyte to the porous layer to electrochemically connect all cathode components, obviating the need for co-sintering to establish contact. The soft nature of the plastic crystal based solid-electrolyte may be able to accommodate the volume change of the cathode material as it cycles. In this device, which contained no liquid component, the initial discharge capacities were similar to those observed in a lithium ion battery configuration using the same cathode powder at C/10 rates.

25 ENERGY STORAGE↗
DOE OSTI2016

Development and Characterization of a High-Solids Deacetylation Process

Dilute-acid pretreatment has proven to be a robust means of converting herbaceous feedstock to fermentable sugars. However, it also releases acetic acid, a known fermentation inhibitor, from acetyl groups present in the biomass. A mild, dilute alkaline extraction stage was implemented prior to acid pretreatment to separate acetic acid from the hydrolysate sugar stream. This step, termed deacetylation, improved the glucose and xylose yields from enzymatic hydrolysis and ethanol yields from fermentation of the sugars relative to the control experiments using dilute-acid pretreatment of native corn stover without deacetylation. While promising, deacetylation as it was historically practiced is conducted at low solids loadings, and at fixed conditions. Thus, many questions have been left unanswered, including the relationship between sodium hydroxide and solids loading, and acetate and xylan solubilization, as well as the impact of temperature and residence time on the process efficacy. A central composite experiment was designed to evaluate the impact of solids loading, sodium hydroxide loading, reaction time and temperature during deacetylation on the acetate and xylan solubilization of corn stover. Using the ANOVA test, it became apparent that neither of the responses was significantly impacted by the solids loading, while the reaction time was a minor factor - the responses were largely driven by reaction temperature and the sodium hydroxide loading. Based on the results, we successfully demonstrated the ability to transition the low-solids (10 % w/w) deacetylation process to a higher-solids process (30 % w/w) with minimal impact on the ability to extract acetate from biomass. Conditions were selected to minimize xylose loss during deacetylation, while also removing 70 % of acetyl groups. The impact of selected conditions on the enzymatic hydrolysis and fermentation was further investigated. In conclusion, evaluation of the whole-process impact demonstrated that despite the upfront reduction in carbohydrate loss during deacetylation, the overall process sugar yields were depressed by the high-solids, low alkali process relative to the historical control. Consequently, ethanol titers were reduced, though strong fermentation performance was still observed, indicating that 70 % acetate removal is sufficient to depress acetic acid concentrations to a level that does not substantially inhibit ethanol fermentation by rZymomo nas.

09 BIOMASS FUELS↗
DOE OSTI2016

Issues concerning the determination of solubility products of sparingly soluble crystalline solids: solubility of HfO2(cr)

Solubility studies were conducted with HfO2(cr) solid as a function HCl and ionic strength ranging from 2.0 to 0.004 mol kg -1. These studies involved 1) using two different amounts of the solid phase, 2) acid washing the bulk solid phase, 3) preheating the solid phase to 1400 °C, and 4) heating amorphous HfO2(am) suspensions to 90°C to ascertain whether the HfO2(am) converts to HfO2(cr) and to determine the solubility from the oversaturation direction. Based on the results of these treatments it is concluded that the HfO2(cr) contains a small fraction of less crystalline, but not amorphous, material [HfO2(lcr)] and this, rather than the HfO2(cr), is the solubility-controlling phase in the range of experimental variables investigated in this study. The solubility data are interpreted using both the Pitzer and SIT models and they provide log10 ??0 values of -(59.75±0.35) and -(59.48±0.41), respectively, for the solubility product of HfO2(lcr) [HfO2(lcr) + 2H2O Hf4+ + 4OH - ]. The log 10 of the solubility product of HfO2(cr) is estimated to be < -63. The observation of a small fraction of less crystalline higher solubility material is consistent with the general picture that mineral surfaces are often structurally and/or compositionally imperfect leading to a higher solubility than the bulk crystalline solid. This study stresses the urgent need, during interpretation of solubility data, of taking precautions to make certain that the observed solubility behavior for sparingly-soluble solids is assigned to the proper solid phase.

Rai, Dhanpat↗
DOE OSTI2011

Summary of Disposable Debris Shields (DDS) Analysis for Development of Solid Debris Collection at NIF

Collection of solid debris from the National Ignition Facility (NIF) is being developed both as a diagnostic tool and as a means for measuring nuclear reaction cross sections relevant to the Stockpile Stewardship Program and nuclear astrophysics. The concept is straightforward; following a NIF shot, the debris that is produced as a result of the capsule and hohlraum explosion would be collected and subsequently extracted from the chamber. The number of nuclear activations that occurred in the capsule would then be measured through a combination of radiation detection and radiochemical processing followed by mass spectrometry. Development of the catcher is challenging due to the complex environment of the NIF target chamber. The collector surface is first exposed to a large photon flux, followed by the debris wind that is produced. The material used in the catcher must be mechanically strong in order to withstand the large amount of energy it is exposed to, as well as be chemically compatible with the form and composition of the debris. In addition, the location of the catcher is equally important. If it is positioned too close to the center of the target chamber, it will be significantly ablated, which could interfere with the ability of the debris to reach the surface and stick. If it is too far away, the fraction of the debris cloud collected will be too small to result in a statistically significant measurement. Material, geometric configuration, and location must all be tested in order to design the optimal debris collection system for NIF. One of the first ideas regarding solid debris collection at NIF was to use the disposable debris shields (DDS), which are fielded over the final optics assemblies (FOA) 7 m away from the center of the target chamber. The DDS are meant to be replaced after a certain number of shots, and if the shields could be subsequently analyzed after removal, it would serve as a mechanism for fielding a relatively large collection area through the use of a part meant to be replaced regularly. The solid angle covered by one of the shields is roughly 10 -4 of 4π. If several shields were analyzed at once, it would increase the solid angle of the collection area accordingly. The glass shields consist of ammonia hardened silica with a sol gel coating and kapton tape around the edge. The square sheets are 14-inch on each side. The original shields were 1 mm thick, but it was determined that a thicker shield (3.3 mm) was more effective in preventing debris from reaching the FOA. The Solid Radchem group received two sets of DDS as part of our evaluation of the potential use of the DDS as solid debris collectors. The first set consisted of two 3.3 mm shields, one each from the top and bottom of the chamber (the '3mm set'). The second set consisted of four 1mm shields, one from the top of the chamber and the other three from the bottom (the 'IFSA set'). For each set, the shields were cut into smaller subsamples, which were then imaged using scanning electron microscopy (SEM) followed by chemical leaching and mass spectrometry. The purpose was to evaluate both the quantity and identity of the debris that was present on the DDS surfaces, and to determine if any of the capsule debris was reaching the chamber walls. In addition, potential enhancement due to gravity in the chamber was evaluated by directly comparing shields fielded in the top and bottom of the chamber. Based on the results, the use of the DDS as debris collectors would be evaluated. The results from both sets were presented to the DDS Working Group. The slides are attached to this document. The 3mm set results are presented first, followed by the results from the IFSA set. In both cases it was determined that a small fraction of the overall debris field was collected on the DDS. This means that the debris that is formed during a NIF shot is condensing out of the plasma and depositing on surfaces closer to the target chamber center, or else it is simply falling to the bottom of the chamber. In either case, it was determined that using the DDS, or fielding a debris collector at the chamber wall, was not feasible for solid debris collection at NIF due to the small amount of debris that had been collected. In addition, since the glass shields suffered quite a bit of damage from particles impacting the surface, glass was ruled out as a collection medium.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2012

Novel Non-Vacuum Fabrication of Solid State Lithium Ion Battery Components

The purpose of this Cooperative Research and Development Agreement (CRADA) between Oak Ridge National Laboratory (ORNL) and Planar Energy Devices, Inc. was to develop large-scale electroless deposition and photonic annealing processes associated with making all-solid-state lithium ion battery cathode and electrolyte layers. However, technical and processing difficulties encountered in 2011 resulted in the focus of the CRADA being redirected solely to annealing of the cathode thin films. In addition, Planar Energy Devices de-emphasized the importance of annealing of the solid-state electrolytes within the scope of the project, but materials characterization of stabilized electrolyte layers was still of interest. All-solid-state lithium ion batteries are important to automotive and stationary energy storage applications because they would eliminate the problems associated with the safety of the liquid electrolyte in conventional lithium ion batteries. However, all-solid-state batteries are currently produced using expensive, energy consuming vacuum methods suited for small electrode sizes. Transition metal oxide cathode and solid-state electrolyte layers currently require about 30-60 minutes at 700-800°C vacuum processing conditions. Photonic annealing requires only milliseconds of exposure time at high temperature and a total of <1 min of cumulative processing time. As a result, these processing techniques are revolutionary and highly disruptive to the existing lithium ion battery supply chain. The current methods of producing all-solid-state lithium ion batteries are only suited for small-scale, low-power cells and involve high-temperature vacuum techniques. Stabilized LiNi x Mn y Co z Al 1-x-y-z O 2 (NMCA) nanoparticle films were deposited onto stainless steel substrates using Planar Energy Devices’ streaming process for electroless electrochemical deposition (SPEED). Since successful SPEED trials were demonstrated by Planar Energy Devices with NMCA prior to 2010, this high-voltage (i.e. 5 V) cathode material was the focus of the project. ORNL had also shown in prior work that photonic annealing can be used to anneal conventionally coated cathode metal oxide structures into the active crystalline phase. Planar Energy Devices also had demonstrated SPEED with solid electrolyte layers consisting of LiGaAlSPO 4 prior to the start of the project.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2015

Determining the Release of Radionuclides from Tank Waste Residual Solids: FY2015 Report

Methodology development for pore water leaching studies has been continued to support Savannah River Site High Level Waste tank closure efforts. For FY2015, the primary goal of this testing was the achievement of target pH and Eh values for pore water solutions representative of local groundwater in the presence of grout or grout-representative (CaCO 3 or FeS) solids as well as waste surrogate solids representative of residual solids expected to be present in a closed tank. For oxidizing conditions representative of a closed tank after aging, a focus was placed on using solid phases believed to be controlling pH and E h at equilibrium conditions. For three pore water conditions (shown below), the target pH values were achieved to within 0.5 pH units. Tank 18 residual surrogate solids leaching studies were conducted over an E h range of approximately 630 mV. Significantly higher Eh values were achieved for the oxidizing conditions (ORII and ORIII) than were previously observed. For the ORII condition, the target Eh value was nearly achieved (within 50 mV). However, E h values observed for the ORIII condition were approximately 160 mV less positive than the target. E h values observed for the RRII condition were approximately 370 mV less negative than the target. Achievement of more positive and more negative E h values is believed to require the addition of non-representative oxidants and reductants, respectively. Plutonium and uranium concentrations measured during Tank 18 residual surrogate solids leaching studies under these conditions (shown below) followed the general trends predicted for plutonium and uranium oxide phases, assuming equilibrium with dissolved oxygen. The highest plutonium and uranium concentrations were observed for the ORIII condition and the lowest concentrations were observed for the RRII condition. Based on these results, it is recommended that these test methodologies be used to conduct leaching studies with actual Tank 18 residual solids material. Actual waste testing will include leaching evaluations of technetium and neptunium, as well as plutonium and uranium.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Development of Operando Nuclear Magnetic Resonance Capabilities for Solid-State Battery Research

Mechanistic information regarding solid-solid interfaces in solid-state batteries remains elusive as its observation requires a non-destructive operando technique. Such a technique does not currently exist. Solid-state nuclear magnetic resonance (NMR) is uniquely suited to address this challenge as it is sensitive to chemistry, structure, and dynamics and can measure buried interfaces. However solid-state NMR requires high speed spinning of the sample at the ‘magic angle’ (MAS) to obtain adequate resolution. The metallic current collectors in a battery are detrimental to spinning in magnetic fields as they generate eddy currents which prevent spinning and dampen the NMR signal. Furthermore, the spinning nature of the MAS NMR experiment requires a wireless means of charging for operando capabilities. These challenges were addressed in this research and operando MAS NMR enabled by optical wireless charging was demonstrated. By limiting the size of the metallic components, we were able to spin a sample holder with electrical leads and a solid-state battery up to a few kilohertz, fast enough for high-resolution NMR. We achieved wireless charging by attaching a photovoltaic cell to the head of the NMR rotor and used a laser to transmit power to the photovoltaic cell. Demonstration of the optical wireless charging was performed by polarizing a liquid electrolyte during an operando MAS NMR measurement. This novel capability is a transformative technique for investigating the mechanistic electrochemical processes in solid-state samples.

25 ENERGY STORAGE↗
DOE OSTI2021

Dual Function Solid State Battery with Self-Forming Self-Healing Electrolyte and Separator (Final Scientific/Technical Report)

Over the course of this program, we have demonstrated an improved rechargeable Li/I2 battery with reduced impedance, improved cyclability, improved Coulombic Efficiency, and the ability to “self-heal” during shorting events. Multi-year efforts have led to the development and improvements in the composition, fabrication, and preparation of the solid state electrolyte, the role of the interface, and design of appropriate test conditions. These investigations have led to significant improvements in Coulombic efficiency. By systematic development of a composite solid state electrolyte, this system is able to self-form upon charge, thus lending itself to long shelf life before use. The initial project objective was to demonstrate a solid-state rechargeable battery based on a Li-metal anode and iodine cathode with a self-forming, self-healing electrolyte and separator with high gravimetric and volumetric energy density. The final deliverables of this project build on a multi-year effort beginning with materials development and design to generate a suitable solid state electrolyte composite with demonstrated higher ionic conductivity compared to the baseline (LiI). Development in cell design and interface modification leading to the generation of rechargeable solid electrolyte cells with Coulombic efficiency improvements of ~3X over initial tests, as well as demonstration of self-healing behavior, where the cells retained their ability to continue extended cycling after shorting events. The hypothesis put forward as part of the initial concept for the project was that the cell chemistry would be self-healing. For example, if a lithium dendrite formed during charge of the cell and reached the iodine cathode, the reaction of the lithium dendrite with the iodine would consume the tip of the dendrite to form lithium iodide, more of the solid electrolyte. The formation of the solid electrolyte would allow the cell to recover and continue to function. This type of self-healing during cycling has been demonstrated and has the potential to improve on safety considerations that stem from shorting events in other Li- containing systems.

25 ENERGY STORAGE↗
DOE OSTI2024

Developing Materials for High-Energy-Density Solid State Li-S Batteries

Solid-state lithium-sulfur batteries are considered to be the next-generation power source for vehicle applications due to their high energy density (up to 3 times more than current Li-ion) and low cost of sulfur (100 times less than conventional cobalt oxide). However, issues with solid-state electrolyte stability, conduction pathways in the sulfur cathode, and the interface between solid-state electrolyte and sulfur cathode must be solved in order to allow commercialization. This project demonstrates the creation of new, advanced materials which overcome these inherent issues. Current approaches based on polymer or liquid electrolyte with additives have been able to improve stability at the cost of efficiency. In contrast, by creating new hybrid materials it is possible to achieve both stability and efficiency. We developed a novel sulfide-based solid electrolyte, a sulfur-carbon composite cathode, and explored various additives to stabilize the interface of solid electrolyte and cathode. After the desired properties were achieved, these materials were integrated into a high-performance solid-state battery, bringing low-cost high-energy solid-state lithium-sulfur batteries one step closer to reality.

25 ENERGY STORAGE↗
DOE OSTI2012

Efficient Theoretical Screening of Solid Sorbents for CO2 Capture Applications*

By combining thermodynamic database mining with first principles density functional theory and phonon lattice dynamics calculations, a theoretical screening methodology to identify the most promising CO2 sorbent candidates from the vast array of possible solid materials has been proposed and validated. The ab initio thermodynamic technique has the advantage of allowing identification of thermodynamic properties of CO2 capture reactions without any experimental input beyond crystallographic structural information of the solid phases involved. For a given solid, the first step is to attempt to extract thermodynamic properties from thermodynamic databases and the available literatures. If the thermodynamic properties of the compound of interest are unknown, an ab initio thermodynamic approach is used to calculate them. These properties expressed conveniently as chemical potentials and heat of reactions, which obtained either from databases or from calculations, are further used for computing the thermodynamic reaction equilibrium properties of the CO2 absorption/desorption cycles. Only those solid materials for which lower capture energy costs are predicted at the desired process conditions are selected as CO2 sorbent candidates and are further considered for experimental validations. Solid sorbents containing alkali and alkaline earth metals have been reported in several previous studies to be good candidates for CO2 sorbent applications due to their high CO2 absorption capacity at moderate working temperatures. In addition to introducing our computational screening procedure, in this presentation we will summarize our results for solid systems composed by alkali and alkaline earth metal oxides, hydroxides, and carbon- ates/bicarbonates to validate our methodology. Additionally, applications of our computational method to mixed solid systems of Li2O with SiO2/ZrO2 with different mixing ratios, our preliminary results showed that increasing the Li2O/SiO2 ratio in lithium silicates increases their corresponding turnover temperatures for CO2 capture reactions. Overall these theoretical predictions are found to be in good agreement with available experimental findings

36 MATERIALS SCIENCE↗
NASA NTRS1990

Optical constants of solid methane

Methane is the most abundant simple organic molecule in the outer solar system bodies. In addition to being a gaseous constituent of the atmospheres of the Jovian planets and Titan, it is present in the solid form as a constituent of icy surfaces such as those of Triton and Pluto, and as cloud condensate in the atmospheres of Titan, Uranus, and Neptune. It is expected in the liquid form as a constituent of the ocean of Titan. Cometary ices also contain solid methane. The optical constants for both solid and liquid phases of CH4 for a wide temperature range are needed for radiative transfer calculations, for studies of reflection from surfaces, and for modeling of emission in the far infrared and microwave regions. The astronomically important visual to near infrared measurements of solid methane optical constants are conspicuously absent from the literature. Preliminary results are presented on the optical constants of solid methane for the 0.4 to 2.6 micrometer region. Deposition onto a substrate at 10 K produces glassy (semi-amorphous) material. Annealing this material at approximately 33 K for approximately 1 hour results in a crystalline material as seen by sharper, more structured bands and negligible background extinction due to scattering. The constant k is reported for both the amorphous and the crystalline (annealed) states. Typical values (at absorption maxima) are in the .001 to .0001 range. Below lambda = 1.1 micrometers the bands are too weak to be detected by transmission through the films less than or equal to 215 micrometers in thickness, employed in the studies to date. Using previously measured values of the real part of the refractive index, n, of liquid methane at 110 K, n is computed for solid methane using the Lorentz-Lorenz relationship. Work is in progress to extend the measurements of optical constants n and k for liquid and solid to both shorter and longer wavelengths, eventually providing a complete optical constants database for condensed CH4.

Khare, Bishun N.↗
NASA NTRS1989

Optical constants of solid methane

Methane is the most abundant simple organic molecule in the outer solar system bodies. In addition to being a gaseous constituent of the atmospheres of the Jovian planets and Titan, it is present in the solid form as a constituent of icy surfaces such as those of Triton and Pluto, and as cloud condensate in the atmospheres of Titan, Uranus, and Neptune. It is expected in the liquid form as a constituent of the ocean of Titan. Cometary ices also contain solid methane. The optical constants for both solid and liquid phases of CH4 for a wide temperature range are needed for radiative transfer calculations, for studies of reflection from surfaces, and for modeling of emission in the far infrared and microwave regions. The astronomically important visual to near infrared measurements of solid methane optical constants are conspicuously absent from the literature. Preliminary results are presented of the optical constants of solid methane for the 0.4 to 2.6 micron region. K is reported for both the amorphous and the crystalline (annealed) states. Using the previously measured values of the real part of the refractive index, n, of liquid methane at 110 K n is computed for solid methane using the Lorentz-Lorentz relationship. Work is in progress to extend the measurements of optical constants n and k for liquid and solid to both shorter and longer wavelengths, eventually providing a complete optical constants database for condensed CH4.

Khare, Bishun N.↗
NASA NTRS1990

Solid-liquid staged combustion space boosters

NASA has begun to evaluate solid-liquid hybrid propulsion for launch vehicle booster. A three-phase program was outlined to identify, acquire, and demonstrate technology needed to approximate solid and liquid propulsion state of the art. Aerojet has completed a Phase 1 study and recommends a solid-liquid staged combustion concept in which turbopump fed LO2 is burned with fuel-rich solid propellant effluent in aft-mounted thrust chambers.These reasonably sized thrust chambers are LO2 regeneratively cooled, supplemented with fuel-rich barrier cooling. Turbopumps are driven by the resulting GO2 coolant in an expander-bleed-burnoff cycle. Turbine exhaust pressurizes the LO2 tankage directly, and the excess is bled into supersonic nozzle splitlines, where it combusts with the fuel rich boundary layer. Thrust vector control is enhanced by supersonic nozzle movement on flexseal mounts. Every hybrid solid-liquid concept examined improves booster energy management and launch propellant safety compared to current solid boosters. Solid-liquid staged combustion improves hybrid performance by improving both combustion efficiency and combustion stability, especially important for large boosters. These improvements result from careful fluid management and use of smaller combustors. The study shows NASA safety, reliability, cost, and performance criteria are best met with this concept, wherein simple hardware relies on several separate emerging technologies, all of which have been demonstrated successfully.

Culver, D. W.↗
NASA NTRS1996

The Global Perspective on the Evolution of Solids in a Protoplanetary Disk

It is currently thought that planets around solar-type stars form by the accumulation of solid matter entrained in a gaseous, turbulent protoplanetary disk. We have developed a model designed to simulate the part of this process that starts from small particles suspended in the gaseous disk at the end of the formation stage, and ends up with most of the solid material aggregated into 1-10-km planetesimals. The major novelty of our approach is its emphasis on the global, comprehensive treatment of the problem, as our model simultaneously keeps track of the evolution of gas and solid particles due to gas-solid coupling, coagulation, sedimentation, and evaporation/condensation. The result of our calculations is the radial distribution of solid material circumnavigating a star in the form of a planetesimal swarm. Such a distribution should well approximate the radial apportionment of condensed components of the planets spread over the radial extent of the mature planetary system. Therefore we view our calculations as an attempt to predict the large-scale architecture of planetary systems and to assess their potential diversity. In particular, we have found that some initial conditions lead to all solids being lost to the star, but we can also identify initial conditions leading to a radial distribution of solid material quite reminiscent of what is found in our solar system.

Stepinski, T. F.↗
NASA NTRS2000

Thermal-Flow Code for Modeling Gas Dynamics and Heat Transfer in Space Shuttle Solid Rocket Motor Joints

A new, thermal-flow simulation code, called SFLOW. has been developed to model the gas dynamics, heat transfer, as well as O-ring and flow path erosion inside the space shuttle solid rocket motor joints by combining SINDA/Glo, a commercial thermal analyzer. and SHARPO, a general-purpose CFD code developed at Thiokol Propulsion. SHARP was modified so that friction, heat transfer, mass addition, as well as minor losses in one-dimensional flow can be taken into account. The pressure, temperature and velocity of the combustion gas in the leak paths are calculated in SHARP by solving the time-dependent Navier-Stokes equations while the heat conduction in the solid is modeled by SINDA/G. The two codes are coupled by the heat flux at the solid-gas interface. A few test cases are presented and the results from SFLOW agree very well with the exact solutions or experimental data. These cases include Fanno flow where friction is important, Rayleigh flow where heat transfer between gas and solid is important, flow with mass addition due to the erosion of the solid wall, a transient volume venting process, as well as some transient one-dimensional flows with analytical solutions. In addition, SFLOW is applied to model the RSRM nozzle joint 4 subscale hot-flow tests and the predicted pressures, temperatures (both gas and solid), and O-ring erosions agree well with the experimental data. It was also found that the heat transfer between gas and solid has a major effect on the pressures and temperatures of the fill bottles in the RSRM nozzle joint 4 configuration No. 8 test.

Wang, Qunzhen↗
NASA NTRS2000

NASA's Design and Development of a Field Goniometer Instrument Using Solid Works

With NASA suffering severe funding cutbacks, engineers at NASA are required to produce state-of-the-art hardware with limited personnel and financial resources. In light of these constraints, the new NASA mandate is to build better, faster and cheaper. In April of 1998, Stennis Space Center's Commercial Remote Sensing Program contracted to the Systems Engineering Division at NASA Ames Research Center to develop a device known as a Field Goniometer. A Field Goniometer is a device that measures bi-directional reflectance of a target, such as vegetation, relative to the sun and an imaging system in an aircraft or spacecraft. The device is able to provide a spectral fingerprint of the surface it is measuring in wavelengths from 350nm-2500nm using a hyperspectral imager. To accomplish this project, several obstacles had to be overcome. First, the design had to be completed in less than four months. Second, due to the complexity of the design, the use of solid modeling was highly desirable but most of the group's solid modelers were assigned to other jobs. Third, the amount of funding available from the customer was one half to one third the funding typically expended for a job of this nature. Our choices for this project were to design with standard 2-D CAD systems currently used in-house or train additional engineers on our existing solids package or purchase a new solid model package. The use of a 2D CAD system was very undesirable due to the complexity of the design. Using our existing solids modeler would have required a learning curve for our engineers that would be incompatible with our schedule. Prior to this project, a member of our design group researched the solid modeling industry and decided to purchase SolidWorks. After examining the product for ease of use, modeling capability, training time required and cost, we decided our highest probability of success would be to design with Solidworks. During the design phase, our fabrication group was able to provide input at the very early stages, which added significant benefit to the final product. Fabrication cost and schedule savings have been realized by having complex part geometries translated directly from the SolidWorks design models to Surfcam and other computer-aided manufacturing (CAM) software. This direct model translation capability optimized the fabrication processes. The end result was that we were able to successfully complete the project on time and on budget. Other advantages of using SolidWorks, as cited by the design team, include a rapid negotiation of the initial learning curve, the ability to develop solid model hardware prototypes (used to communicate the design intent to both the customer and the fabricator), and the ability to work as a team collaborating on a large, complex model. These types of tools and efforts represent our response to NASA's challenge to produce higher quality products within shorter design and fabrication times.

Turner, Mark↗
NASA NTRS2003

Solid Hydrogen Particles and Flow Rates Analyzed for Atomic Fuels

The experiments were conducted at Glenn's Small Multipurpose Research Facility (SMIRF, ref. 5). The experimental setup was placed in the facility's vacuum tank to prevent heat leaks and subsequent boiloff of the liquid helium. Supporting systems maintained the temperature and pressure of the liquid helium bath where the solid particles were created. Solid hydrogen particle formation was tested from February 23 to April 2, 2001. Millimeter-sized solid-hydrogen particles were formed in a Dewar of liquid helium as a prelude to creating atomic fuels and propellants for aerospace vehicles. Atomic fuels or propellants are created when atomic boron, carbon, or hydrogen is stored in solid hydrogen particles. The current testing characterized the solid hydrogen particles without the atomic species, as a first step to creating a feed system for the atomic fuels and propellants. This testing did not create atomic species, but only sought to understand the solid hydrogen particle formation and behavior in the liquid helium. In these tests, video images of the solid particle formation were recorded, and the total mass flow rate of the hydrogen was measured. The mass of hydrogen that went into the gaseous phase was also recorded using a commercially available residual gas analyzer. The temperatures, pressures, and flow rates of the liquids and gases in the test apparatus were recorded as well. Testing conducted in 1999 recorded particles as small as 2 to 5 mm in diameter. The current testing extended the testing conditions to a very cold Dewar ullage gas of about 20 to 90 K above the 4 K liquid helium. With the very cold Dewar gas, the hydrogen freezing process took on new dimensions, in some cases creating particles so small that they seemed to be microscopic, appearing as infinitesimally small scintillations on the videotaped images.

Palaszewski, Bryan A.↗
NASA NTRS2009

NiF2/NaF:CaF2/Ca Solid-State High-Temperature Battery Cells

Experiments and theoretical study have demonstrated the promise of all-solid-state, high-temperature electrochemical battery cells based on NiF2 as the active cathode material, CaF2 doped with NaF as the electrolyte material, and Ca as the active anode material. These and other all-solid-state cells have been investigated in a continuing effort to develop batteries for instruments that must operate in environments much hotter than can be withstood by ordinary commercially available batteries. Batteries of this type are needed for exploration of Venus (where the mean surface temperature is about 450 C), and could be used on Earth for such applications as measuring physical and chemical conditions in geothermal wells and oil wells. All-solid-state high-temperature power cells are sought as alternatives to other high-temperature power cells based, variously, on molten anodes and cathodes or molten eutectic salt electrolytes. Among the all-solid-state predecessors of the present NiF2/NaF:CaF2/Ca cells are those described in "Solid-State High-Temperature Power Cells" (NPO-44396), NASA Tech Briefs, Vol. 32, No. 5 (May 2008), page 40. In those cells, the active cathode material is FeS2, the electrolyte material is a crystalline solid solution of equimolar amounts of Li3PO4 and LiSiO4, and the active anode material is Li contained within an alloy that remains solid in the intended high operational temperature range.

West, William↗