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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 271 records · Page 15

Progress in Air Separation with the Vortex Tube

The current study is characterized by two distinct phases in the development of the vortex tube (VT) technology as a primary means for in-flight air separation. The purpose of the first phase was to systematically identify parameters that influence oxygen concentration and recovery and to quantify the extent of that influence. To that end, the project team used a series of planned factorial experiments to identify statistically significant variables (factors) and their interactions. These experiments identified a best range of the operating envelope that includes nozzle diameter, orifice diameter, inlet air pressure, and liquid phase content in the inlet air. The best results observed in this envelope were an oxygen content of approximately 68% and a recovery factor of approximately 38%. The primary objectives of the second phase of the current study were to investigate the application effects of the two different air separation efficiency enhancement methods. One of these methods resulted in a concentration increase of 12% and second resulted in a concentration increase of 5%. Several aspects of these methods application are subject to optimize.

Balepin, Vladimir↗

Progress in Air Separation with the Vortex Tube

The current study is characterized by two distinct phases in the development of the vortex tube (VT) technology as a primary means for in-flight air separation. The purpose of the first phase was to systematically identify parameters that influence oxygen concentration and recovery and to quantify the extent of that influence. To that end, the project team used a series of planned factorial experiments to identify statistically significant variables (factors) and their interactions. These experiments identified a best range of the operating envelope that includes nozzle diameter, orifice diameter, inlet air pressure, and liquid phase content in the inlet air. The best results observed in this envelope were an oxygen content of approximately 68% and a recovery factor of approximately 38%. The primary objectives of the second phase of the current study were to investigate the application effects of the two different air separation efficiency enhancement methods. One of these methods resulted in a concentration increase of 12% and second resulted in a concentration increase of 5%. Several aspects of these methods application are subject to optimize.

Balepin, V.↗

Closed Loop Active Flow Separation Detection and Control in a Multistage Compressor

Active closed loop flow control was successfully demonstrated on a full annulus of stator vanes in a low speed axial compressor. Two independent methods of detecting separated flow conditions on the vane suction surface were developed. The first technique detects changes in static pressure along the vane suction surface, while the second method monitors variation in the potential field of the downstream rotor. Both methods may feasibly be used in future engines employing embedded flow control technology. In response to the detection of separated conditions, injection along the suction surface of each vane was used. Injected mass flow on the suction surface of stator vanes is known to reduce separation and the resulting limitation on static pressure rise due to lowered diffusion in the vane passage. A control algorithm was developed which provided a proportional response of the injected mass flow to the degree of separation, thereby minimizing the performance penalty on the compressor system.

Bright, Michelle M.↗

Launch Vehicle Propulsion Design with Multiple Selection Criteria

The approach and techniques described herein define an optimization and evaluation approach for a liquid hydrogen/liquid oxygen single-stage-to-orbit system. The method uses Monte Carlo simulations, genetic algorithm solvers, a propulsion thermo-chemical code, power series regression curves for historical data, and statistical models in order to optimize a vehicle system. The system, including parameters for engine chamber pressure, area ratio, and oxidizer/fuel ratio, was modeled and optimized to determine the best design for seven separate design weight and cost cases by varying design and technology parameters. Significant model results show that a 53% increase in Design, Development, Test and Evaluation cost results in a 67% reduction in Gross Liftoff Weight. Other key findings show the sensitivity of propulsion parameters, technology factors, and cost factors and how these parameters differ when cost and weight are optimized separately. Each of the three key propulsion parameters; chamber pressure, area ratio, and oxidizer/fuel ratio, are optimized in the seven design cases and results are plotted to show impacts to engine mass and overall vehicle mass.

Shelton, Joey D.↗

Microchannel reactive distillation for the conversion of aqueous ethanol to ethylene

Here we demonstrate the proof-of-concept for microchannel reactive distillation for alcohol-to-jet application: combining ethanol/water separation and ethanol dehydration in one unit operation. Ethanol is first distilled into the vapor phase, converted to ethylene and water, and then the water co-product is condensed to shift the reaction equilibrium. Process intensification is achieved through rapid mass transfer—ethanol stripping from thin wicks using novel microchannel architectures—leading to lower residence time and improved separation efficiency. Energy savings are realized with integration of unit operations. For example, heat of condensing water can offset vaporizing ethanol. Furthermore, the dehydration reaction equilibrium shifts towards completion by immediate removal of the water byproduct upon formation while maintaining aqueous feedstock in the condensed phase. For aqueous ethanol feedstock (40% w ), 71% ethanol conversion with 91% selectivity to ethylene was demonstrated at 220 °C, 600 psig, and 0.28 h -1 wt hour space velocity. 2.7 stages of separation were also demonstrated, under these conditions, using a device length of 8.3 cm. This provides a height equivalent of a theoretical plate (HETP), a measure of separation efficiency, of ~3.3 cm. By comparison, conventional distillation packing provides an HETP of ~30 cm. Thus, 9.1× reduction in HETP was demonstrated over conventional technology, providing a means for significant energy savings and an example of process intensification. Finally, preliminary process economic analysis indicates that by using microchannel reactive distillation technology, the operating and capital costs for the ethanol separation and dehydration portion of an envisioned alcohol-to-jet process could be reduced by at least 35% and 55%, respectively, relative to the incumbent technology, provided future improvements to microchannel reactive distillation design and operability are made.

10 SYNTHETIC FUELS↗

Reconfigurable Transceiver and Software-Defined Radio Architecture and Technology Evaluated for NASA Space Communications

The NASA Glenn Research Center is investigating the development and suitability of a software-based open-architecture for space-based reconfigurable transceivers (RTs) and software-defined radios (SDRs). The main objectives of this project are to enable advanced operations and reduce mission costs. SDRs are becoming more common because of the capabilities of reconfigurable digital signal processing technologies such as field programmable gate arrays and digital signal processors, which place radio functions in firmware and software that were traditionally performed with analog hardware components. Features of interest of this communications architecture include nonproprietary open standards and application programming interfaces to enable software reuse and portability, independent hardware and software development, and hardware and software functional separation. The goals for RT and SDR technologies for NASA space missions include prelaunch and on-orbit frequency and waveform reconfigurability and programmability, high data rate capability, and overall communications and processing flexibility. These operational advances over current state-of-art transceivers will be provided to reduce the power, mass, and cost of RTs and SDRs for space communications. The open architecture for NASA communications will support existing (legacy) communications needs and capabilities while providing a path to more capable, advanced waveform development and mission concepts (e.g., ad hoc constellations with self-healing networks and high-rate science data return). A study was completed to assess the state of the art in RT architectures, implementations, and technologies. In-house researchers conducted literature searches and analysis, interviewed Government and industry contacts, and solicited information and white papers from industry on space-qualifiable RTs and SDRs and their associated technologies for space-based NASA applications. The white papers were evaluated, compiled, and used to assess RT and SDR system architectures and core technology elements to determine an appropriate investment strategy to advance these technologies to meet future mission needs. The use of these radios in the space environment represents a challenge because of the space radiation suitability of the components, which drastically reduces the processing capability. The radios available for space are considered to be RTs (as opposed to SDRs), which are digitally programmable radios with selectable changes from an architecture combining analog and digital components. The limited flexibility of this design contrasts against the desire to have a power-efficient solution and open architecture.

Reinhart, Richard C.↗

Wavefront tilt feedforward for the formation interferometer testbad (FIT)

Separated spacecraft interferometry is a candidate architecture for several future NASA missions. The Formation Interferometer Testbed (FIT) is a ground based testbed dedicated to the validation of this key technology for a formation of two spacecraft. In separated spacecraft interferometry, the residual relative motion of the component spacecraft must be compensated for by articulation of the optical components. In this paper, the design of the FIT interferometer pointing control system is described. This control system is composed of a metrology pointing loop that maintains an optical link between the two spacecraft and two stellar pointing loops for stabilizing the stellar wavefront at both the right and left apertures of the instrument. A novel feedforward algorithm is used to decouple the metrology loop from the left side stellar loop. Experimental results from the testbed are presented that verify this approach and that fully demonstrate the performance of the algorithm.

formation flying↗

Hybrid propulsion technology program: Phase 1, volume 1

A number of booster propulsion system concepts are being considered for the next generation of manned and unmanned space launch vehicles. The one propulsion system concept that has potential for reducing costs with increased safety, reliability, and performance is hybrid propulsion (HP). A HP system may be thought of as a liquid propulsion system with solid fuel or a solid propulsion system with a liquid oxidizer. The liquid propulsion features that are most attractive are the higher specific impulse, clean exhaust, separated propellants, and oxidizer loading just prior to launch. The most attractive solid propulsion features includes low life cycle costs, no rotating machinery, compact size, and a robust case. In addition, a HP system has a robust LO2 tank; provides thrust control for ignition, to alleviate flight loads, and for thrust termination; and uses an inert grain that is not sensitive to anomalies such as cracks, voids, and separations. The object is to develop the technology to enable the application of HP to manned and unmanned space launch vehicles. This program will identify the necessary technology, acquire that technology, and demonstrate that technology. This volume is the executive summary.

Schuler, A. L.↗

Hydrogen Research at Florida Universities

This final report describes the R&D activities and projects conducted for NASA under the 6-year NASA Hydrogen Research at Florida Universities grant program. Contained within this report are summaries of the overall activities, one-page description of all the reports funded under this program and all of the individual reports from each of the 29 projects supported by the effort. The R&D activities cover hydrogen technologies related to production, cryogenics, sensors, storage, separation processes, fuel cells, resource assessments and education. In the span of 6 years, the NASA Hydrogen Research at Florida Universities program funded a total of 44 individual university projects, and employed more than 100 faculty and over 100 graduate research students in the six participating universities. Researchers involved in this program have filed more than 20 patents in all hydrogen technology areas and put out over 220 technical publications in the last 2 years alone. This 6 year hydrogen research program was conducted by a consortium of six Florida universities: Florida International University (FIU) in Miami, Florida State University (FSU) and Florida A&M University (FAMU) in Tallahassee, University of Central Florida (UCF) in Orlando, University of South Florida (USF) in Tampa, and University of Florida (UF) in Gainesville. The Florida Solar Energy Center (FSEC) of the University of Central Florida managed the research activities of all consortium member universities except those at the University of Florida. This report does not include any of the programs or activities conducted at the University of Florida, but can be found in NASA/CR-2008-215440-PART 1-3.

Block, David L.↗

Selective partitioning and uphill transport enable effective Li/Mg ion separation by negatively charged membranes

Efficient separation of lithium (Li + ) and magnesium (Mg 2+ ) is critical for enhancing sustainable lithium extraction from natural brines, which is vital for battery production and renewable energy technologies. Here we present a method for highly selective Li + /Mg 2+ separation driven by concentration gradients across negatively charged membranes with high charge densities. In contrast to typical electric field-driven transport in negatively charged membranes, where divalent cations generally permeate faster than monovalent cations, Li + ions in our system permeate the membrane at substantially higher rates than Mg 2+ ions. This unexpected selectivity stems from the selective ion partitioning properties of the membrane and the uphill transport of Mg 2+ ions against their external concentration gradient. We demonstrate the efficacy of this separation approach through bench-scale dialysis experiments using a model Atacama brine solution, achieving efficient separation of monovalent and divalent cations. As a result, the high separation efficiency observed in this study suggests a promising approach for monovalent/divalent ion separations, offering higher selectivity compared to current technologies.

36 MATERIALS SCIENCE↗

Oxygen production using solid-state zirconia electrolyte technology

High purity oxygen is required for a number of scientific, medical, and industrial applications. Traditionally, these needs have been met by cryogenic distillation or pressure swing adsorption systems designed to separate oxygen from air. Oxygen separation from air via solid-state zirconia electrolyte technology offers an alternative to these methods. The technology has several advantages over the traditional methods, including reliability, compactness, quiet operation, high purity output, and low power consumption.

Suitor, Jerry W.↗

New Flight Rules to Enable the Era of Aerial Mobility in the National Airspace System

In the 21st Century, new aviation markets, vehicle types, and technologies are fast emerging, inspiring new operational concepts for the National Airspace System such as Unmanned Aircraft Systems Traffic Management and Urban Air Mobility. These novel operations envision a dramatic increase in aerial mobility, or the ability to navigate freely through the airspace with unprecedented access and operational flexibility. Implementing these concepts presents a major challenge to the existing operational modes of Visual Flight Rules (VFR) and Instrument Flight Rules (IFR), developed under the limitations of early 20th Century technology and procedures to ensure safe navigation and separation from traffic. To meet this challenge and to support the needs of operators in the 21st Century and beyond, this paper proposes that VFR and IFR be augmented by new flight rules – Digital Flight Rules (DFR) – that leverage modern and emerging technologies and are not bound by restrictions borne of the state of technology 75-100 years ago. The objective of DFR is to provide safe and unfettered access to the airspace to all participating vehicle operators under all visibility conditions without incurring the limitations in operational flexibility inherent to IFR and even VFR. Advancements in communications, navigation, surveillance, aircraft connectivity, information access, automation technology, and supporting ground infrastructure provide the opportunity for the vehicle operator to engage at an unprecedented level in managing their flights regardless of flight visibility. Under DFR, these advancements enable the vehicle operator to assume full responsibility for traffic separation and therefore full trajectory management authority in all visibility conditions and airspace regions. The changes in roles and responsibilities are expected to enable greater airspace access and operational flexibility than afforded by IFR and VFR, thus enabling the emergence of new operations and a new era of advanced aerial mobility.

Mobility↗

Digital Flight: Enabling the Era of Scalable Mobility in the National Airspace System

In the 21st Century, new aviation markets, vehicle types, and technologies are fast emerging, inspiring new operational concepts for the National Airspace System such as Unmanned Aircraft Systems Traffic Management and Urban Air Mobility. These novel operations envision a dramatic increase in aerial mobility, or the ability to navigate freely through the airspace with unprecedented access and operational flexibility. Implementing these concepts presents a major challenge to the existing operational modes of Visual Flight Rules (VFR) and Instrument Flight Rules (IFR), developed under the limitations of early 20th Century technology and procedures to ensure safe navigation and separation from traffic. To meet this challenge and to support the needs of operators in the 21st Century and beyond, this paper proposes that VFR and IFR be augmented by new flight rules – Digital Flight Rules (DFR) – that leverage modern and emerging technologies and are not bound by restrictions borne of the state of technology 75-100 years ago. The objective of DFR is to provide safe and unfettered access to the airspace to all participating vehicle operators under all visibility conditions without incurring the limitations in operational flexibility inherent to IFR and even VFR. Advancements in communications, navigation, surveillance, aircraft connectivity, information access, automation technology, and supporting ground infrastructure provide the opportunity for the vehicle operator to engage at an unprecedented level in managing their flights regardless of flight visibility. Under DFR, these advancements enable the vehicle operator to assume full responsibility for traffic separation and therefore full trajectory management authority in all visibility conditions and airspace regions. The changes in roles and responsibilities are expected to enable greater airspace access and operational flexibility than afforded by IFR and VFR, thus enabling the emergence of new operations and a new era of advanced aerial mobility.

Mobility↗

Advances in membrane technology for the NASA redox energy storage system

Anion exchange membranes used in the system serve as a charge transferring medium as well as a reactant separator and are the key enabling component in this storage technology. Each membrane formulation undergoes a series of screening tests for area-resistivity, static (non-flow) diffusion rate determination, and performance in Redox systems. The CDIL series of membranes has, by virtue of its chemical stability and high ion exchange capacity, demonstrated superior properties in the redox environment. Additional resistivity results at several acid and iron solution concentrations, iron diffusion rates, and time dependent iron fouling of the various membrane formulations are presented in comparison to past standard formulations.

Ling, J. S.↗

Surface Nuclear Power for Human Mars Missions

The Design Reference Mission for NASA's human mission to Mars indicates the desire for in-situ propellant production and bio-regenerative life systems to ease Earth launch requirements. These operations, combined with crew habitation and science, result in surface power requirements approaching 160 kilowatts. The power system, delivered on an early cargo mission, must be deployed and operational prior to crew departure from Earth. The most mass efficient means of satisfying these requirements is through the use of nuclear power. Studies have been performed to identify a potential system concept using a mobile cart to transport the power system away from the Mars lander and provide adequate separation between the reactor and crew. The studies included an assessment of reactor and power conversion technology options, selection of system and component redundancy, determination of optimum separation distance, and system performance sensitivity to some key operating parameters. The resulting system satisfies the key mission requirements including autonomous deployment, high reliability, and cost effectiveness at a overall system mass of 12 tonnes and a stowed volume of about 63 cu m.

Mason, Lee S.↗

Pinning ångström-size solid ionic channels for rare-earth element separation

High-purity rare-earth elements are essential for modern technologies, yet current solvent extraction processes are energy-intensive and environmentally harmful because of inadequate selectivity and ligand toxicity. Although combining size exclusion and binding affinity can improve lanthanide separation, the role of long-range confinement remains underexplored. Here we report lanthanide separation in aqueous systems using extremely confined manganese oxide solid ionic channels with optimized layer spacing. Different lanthanides induce distinct solid-state phase transformations in manganese oxide, creating a strong driving force for separation. Two lanthanide groups, differing by ~1.4 Å in spacing, were identified and confirmed to be stable by density functional theory. The narrower confinement of heavier Group II lanthanides improves cross-group separation by increasing the dehydration barrier for lighter Group I lanthanides without inducing strong binding. Here, we further developed a strategy to pin the confinement dimensions and enhance same-group separation, increasing enrichment factors for La–Nd and La–Pr pairs from 1.6 ± 0.1 and 1.5 ± 0.1 to 5.4 ± 0.1 and 4.2 ± 0.1, respectively.

Chemical engineering↗

Applicability of Digital Flight to the Operations of Self-Piloted Unmanned Aircraft Systems in the National Airspace System

Unmanned Aircraft Systems (UAS) hold great promise for a new era of specialized missions, including personal air transportation, cargo flight operations, aerial surveys, inspections, firefighting and more. The anticipated market growth is significant. To unlock its scalability and incumbent benefits requires a human to oversee multiple flights simultaneously, focusing on multi-vehicle mission management and relinquishing to autonomous systems their active role in controlling the aircrafts’ flight paths. Key to the realization of these scalability benefits is minimally-encumbered access to the National Airspace System (NAS), which poses some unique challenges for self-piloted UAS aircraft operations. These include the requirement for compatibility with existing airspace structures and operations including Visual Flight Rules (VFR) and Instrument Flight Rules (IFR), neither of which were developed to accommodate the unique needs and capabilities of UAS. This paper explores the applicability of Digital Flight to the operations of self-piloted UAS. As proposed by NASA, Digital Flight is a flight operations capability, enabled by a set of cooperative procedures and digital technologies, in which flight operators ensure flight-path safety through automated separation and flight path management in lieu of visual procedures and Air Traffic Control separation services. Flights operating under potentially-forthcoming rules of Digital Flight employ advanced automation technologies, information sharing, connectivity to operational data, and cooperative behaviors through distributed decision-making to maintain safety and achieve mission objectives. Designed for integration with VFR and IFR operations in shared NAS airspace, potentially as a third set of flight rules, Digital Flight may provide the mechanism for UAS operators – and all aircraft operators – to scale and diversify their operations beyond what is achievable under current regulations.

DFR↗