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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Impact of future fuel properties on aircraft engines and fuel systems

The effect of modifications in hydrocarbon jet fuels specifications on engine performance, component durability and maintenance, and aircraft fuel system performance is discussed. Specific topics covered include: specific fuel consumption; ignition at relight limits; exhaust emissions; combustor liner temperatures; carbon deposition; gum formation in fuel nozzles, erosion and corrosion of turbine blades and vanes; deposits in fuel system heat exchangers; and pumpability and flowability of the fuel. Data that evaluate the ability of current technology aircraft to accept fuel specification changes are presented, and selected technological advances that can reduce the severity of the problems are described and discussed.

Rudey, R. A.↗
NASA NTRS1978

Impact of future fuel properties on aircraft engines and fuel systems

From current projections of the availability of high-quality petroleum crude oils, it is becoming increasingly apparent that the specifications for hydrocarbon jet fuels may have to be modified. The problems that are most likely to be encountered as a result of these modifications relate to engine performance, component durability and maintenance, and aircraft fuel-system performance. The effect on engine performance will be associated with changes in specific fuel consumption, ignition at relight limits, at exhaust emissions. Durability and maintenance will be affected by increases in combustor liner temperatures, carbon deposition, gum formation in fuel nozzles, and erosion and corrosion of turbine blades and vanes. Aircraft fuel-system performance will be affected by increased deposits in fuel-system heat exchangers and changes in the pumpability and flowability of the fuel. The severity of the potential problems is described in terms of the fuel characteristics most likely to change in the future. Recent data that evaluate the ability of current-technology aircraft to accept fuel specification changes are presented, and selected technological advances that can reduce the severity of the problems are described and discussed.

Rudey, R. A.↗
NASA NTRS2003

Industry Support

NASA Glenn Research Center (GRC) is responsible for the Advanced Communications for Air Traffic Management (AC/ATM) Project, a sub-element task of the Advanced Air Transportation Technologies (AATT) Project of the NASA Aviation System Capacity Program (ASC). The AC/ATM Project is developing new communications technologies and tools that will improve throughput in the U.S. Air Traffic Control System. The goal of the AC/ATM Project is to enable a communications infrastructure providing the capacity, efficiency, and flexibility necessary to realize benefits of the future mature Free-Flight environment. The capabilities and scope of communications technologies needed to accomplish this goal depend on characteristics of the future Free-Flight environment. There are many operational concepts being proposed for a future ATM system to enable user flexibility and efficiency. GRC s focus is on developing new technologies and techniques to support the digital communication of information involving airborne and ground-based users. However, the technologies and techniques must be integrated with the systems and services that industry and the Federal Aviation Administration (FAA) are developing. Thus, GRC needs to monitor and provide input to the various industry and FAA organizations and committees that are specifying new systems and services. Adoption of technologies by the FAA is partially dependent on acceptance of the technology by the aviation community. The commercial aviation community in particular would like to adopt technologies that can be used throughout the world. As a result, the adoption of common or at least compatible technologies by European countries is a key factor in getting commitments to those technologies by the US aviation community. GRC desires to keep informed of European activities that relate to aviation communication technologies, particularly those that are being supported by Eurocontrol.

Source record↗
NASA NTRS2002

Human Factors Process Task Analysis Liquid Oxygen Pump Acceptance Test Procedure for the Advanced Technology Development Center

A process task analysis effort was undertaken by Dynacs Inc. commencing in June 2002 under contract from NASA YA-D6. Funding was provided through NASA's Ames Research Center (ARC), Code M/HQ, and Industrial Engineering and Safety (IES). The John F. Kennedy Space Center (KSC) Engineering Development Contract (EDC) Task Order was 5SMA768. The scope of the effort was to conduct a Human Factors Process Failure Modes and Effects Analysis (HF PFMEA) of a hazardous activity and provide recommendations to eliminate or reduce the effects of errors caused by human factors. The Liquid Oxygen (LOX) Pump Acceptance Test Procedure (ATP) was selected for this analysis. The HF PFMEA table (see appendix A) provides an analysis of six major categories evaluated for this study. These categories include Personnel Certification, Test Procedure Format, Test Procedure Safety Controls, Test Article Data, Instrumentation, and Voice Communication. For each specific requirement listed in appendix A, the following topics were addressed: Requirement, Potential Human Error, Performance-Shaping Factors, Potential Effects of the Error, Barriers and Controls, Risk Priority Numbers, and Recommended Actions. This report summarizes findings and gives recommendations as determined by the data contained in appendix A. It also includes a discussion of technology barriers and challenges to performing task analyses, as well as lessons learned. The HF PFMEA table in appendix A recommends the use of accepted and required safety criteria in order to reduce the risk of human error. The items with the highest risk priority numbers should receive the greatest amount of consideration. Implementation of the recommendations will result in a safer operation for all personnel.

Diorio, Kimberly A.↗
NASA NTRS2002

Human Factors Process Task Analysis: Liquid Oxygen Pump Acceptance Test Procedure at the Advanced Technology Development Center

This viewgraph presentation provides information on Human Factors Process Failure Modes and Effects Analysis (HF PFMEA). HF PFMEA includes the following 10 steps: Describe mission; Define System; Identify human-machine; List human actions; Identify potential errors; Identify factors that effect error; Determine likelihood of error; Determine potential effects of errors; Evaluate risk; Generate solutions (manage error). The presentation also describes how this analysis was applied to a liquid oxygen pump acceptance test.

Diorio, Kimberly A.↗
NASA NTRS1992

Overview of NASA HSR high-lift program

The viewgraphs and discussion of the NASA High-Speed Research (HSR) Program being conducted to develop the technologies essential for the successful U.S. development of a commercial supersonic air transport in the 2005 timeframe are provided. The HSR program is being conducted in two phases, with the first phase stressing technology to ensure environmental acceptability and the second phase stressing technology to make the vehicle economically viable (in contrast to the current Concorde design). During Phase 1 of the program, a key element of the environmental emphases is minimization of community noise through effective engine nozzle noise suppression technology and through improving the performance of high-lift systems. An overview of the current Phase 1 High-Lift Program, directed at technology for community noise reduction, is presented. The total target for takeoff engine noise reduction to meet expected regulations is believed to be about 20 EPNdB. The high-lift research is stressing the exploration of innovative high-lift concepts and advanced flight operations procedures to achieve a substantial (approximately 6 EPNdB) reduction in community noise to supplement the reductions expected from engine nozzle noise suppression concepts; primary concern is focused on the takeoff and climbout operations where very high engine power settings are used. Significant reductions in aerodynamic drag in this regime will allow substantial reductions in the required engine thrust levels and therefore reductions in the noise generated.

Gilbert, William P.↗
NASA NTRS1973

Current technology in ion and electrothermal propulsion

High performance propulsion devices, such as electrostatic ion engines and electrothermal thrusters, are achieving wide user acceptance. The current technology and projected development trends in the areas of ion and electrothermal propulsion systems and components are surveyed.

Finke, R. C.↗
NASA NTRS2018

Initial Developments Toward an Active Noise Control System for Small Unmanned Aerial Systems

Small unmanned aerial systems have the potential to expand commercial markets from package delivery to infrastructure inspection. Many missions, however, require the vehicles to operate in close proximity to people, where community noise concerns could ultimately limit vehicle acceptability. Therefore, noise control technologies may be needed to achieve an acceptable noise signature and enable widespread use of these vehicles. The purpose of this paper is to assess the feasibility of using loudspeakers attached to the vehicle to actively reduce noise. More specifically, this initial study explores the possibility of using a single loudspeaker to reduce the noise from an isolated rotor. Tests performed in an anechoic chamber with a 7.6 cm diameter speaker and 23.9 cm diameter rotor are used to demonstrate the potential benefits and limitations of the concept. Results confirm that active noise control can work in this application with measured tonal reductions of over 30 dB in specific directions. However, since the radiation characteristics of the speaker are different than the rotor, amplification is observed in other directions. This technology has the potential to create a “cone of silence”, which could be steered during flight operations to minimize the impact on noise sensitive areas.

Schiller, Noah H.↗
NASA NTRS2016

High Data Rate Architecture (HiDRA)

One of the greatest challenges in developing new space technology is in navigating the transition from ground based laboratory demonstration at Technology Readiness Level 6 (TRL-6) to conducting a prototype demonstration in space (TRL-7). This challenge is com- pounded by the relatively low availability of new spacecraft missions when compared with aeronautical craft to bridge this gap, leading to the general adoption of a low-risk stance by mission management to accept new, unproven technologies into the system. Also in consideration of risk, the limited selection and availability of proven space-grade components imparts a severe limitation on achieving high performance systems by current terrestrial technology standards. Finally from a space communications point of view the long duration characteristic of most missions imparts a major constraint on the entire space and ground network architecture, since any new technologies introduced into the system would have to be compliant with the duration of the currently deployed operational technologies, and in some cases may be limited by surrounding legacy capabilities. Beyond ensuring that the new technology is verified to function correctly and validated to meet the needs of the end users the formidable challenge then grows to additionally include: carefully timing the maturity path of the new technology to coincide with a feasible and accepting future mission so it flies before its relevancy has passed, utilizing a limited catalog of available components to their maximum potential to create meaningful and unprecedented new capabilities, designing and ensuring interoperability with aging space and ground infrastructures while simultaneously providing a growth path to the future. The International Space Station (ISS) is approaching 20 years of age. To keep the ISS relevant, technology upgrades are continuously taking place. Regarding communications, the state-of-the-art communication system upgrades underway include high-rate laser terminals. These must interface with the existing, aging data infrastructure. The High Data Rate Architecture (HiDRA) project is designed to provide networked store, carry, and forward capability to optimize data flow through both the existing radio frequency (RF) and new laser communications terminal. The networking capability is realized through the Delay Tolerant Networking (DTN) protocol, and is used for scheduling data movement as well as optimizing the performance of existing RF channels. HiDRA is realized as a distributed FPGA memory and interface controller that is itself controlled by a local computer running DTN software. Thus HiDRA is applicable to other arenas seeking to employ next-generation communications technologies, e.g. deep space. In this paper, we describe HiDRA and its far-reaching research implications.

DTN↗
NASA NTRS1997

Demonstration of Oxygen and Carbon Monoxide Propellants for Mars Missions

Currently, proposed planetary exploration missions must be small, with low costs and a short development time. Relatively high-risk technologies are being accepted for such missions if they meet these guidelines. For a Mars sample-return mission, one of the higher risk technologies is the use of return propellants produced from indigenous materials such as the Martian atmosphere. This consists of 96 percent carbon dioxide, which can be processed into oxygen and carbon monoxide. This year, the NASA Lewis Research Center completed the experimental evaluation and subscale technology development of an oxygen/carbon monoxide propellant combination. Previous research included ignition characterization, combustion performance, and heat transfer characterization with gaseous propellants at room temperature. In this year s tests, we studied the ignition characteristics and combustion of oxygen and carbon monoxide at near liquid temperatures. The mixture ratio boundaries for oxygen and carbon monoxide were determined as a function of propellant temperature in a spark torch igniter. With both propellants at room temperature, the ignition range was between 0.50 and 1.44; and with both propellants chilled to near-liquid temperatures, it was between 2.4 and 3.1. Statistical analysis of the mean value of the ignition boundaries provided models that describe the combination of oxygen temperature, carbon monoxide temperature, and mixture ratio that resulted in ignition. This range is the larger boxed area shown in the figure. The smaller boxed area indicates the range at which there is a 90-percent confidence that ignition will occur. The relatively small range at only 90-percent confidence indicates that using the oxygen/carbon monoxide combination as its own ignition source may not be the best design for a remote engine operating on Mars. Tests also were performed in a simulated small rocket engine that used oxygen/hydrogen combustion gases as the ignition source for oxygen/carbon monoxide. In these experiments, the oxygen/carbon monoxide was successfully ignited in eight of eight tests at a mixture ratio of 0.52. In addition, the oxygen/carbon monoxide maintained steady combustion after the oxygen/hydrogen ignition source was removed, verifying that the oxygen/carbon monoxide rocket engine should continue to be included in mission plans as return propulsion from Mars.

Linne, Diane L.↗
NASA NTRS1989

H(2)- and H(infinity)-design tools for linear time-invariant systems

Recent advances in optimal control have brought design techniques based on optimization of H(2) and H(infinity) norm criteria, closer to be attractive alternatives to single-loop design methods for linear time-variant systems. Significant steps forward in this technology are the deeper understanding of performance and robustness issues of these design procedures and means to perform design trade-offs. However acceptance of the technology is hindered by the lack of convenient design tools to exercise these powerful multivariable techniques, while still allowing single-loop design formulation. Presented is a unique computer tool for designing arbitrary low-order linear time-invarient controllers than encompasses both performance and robustness issues via the familiar H(2) and H(infinity) norm optimization. Application to disturbance rejection design for a commercial transport is demonstrated.

Ly, Uy-Loi↗
NASA NTRS1994

New Developments and Research Findings: NASA Hydrazine Arcjets

In 1984, the market for commercial geosynchronous communications satellites (comsats) was expanding and there was strong competition between spacecraft builders for market share. The propellant required for the north-south stationkeeping (NSSK) function was a major mission limiter, and the small chemical and resistojet systems then in use were at or near their physical limits. Thus, conditions were right for the development of a high performance NSSK system, and after an extensive survey of both propulsion technologies and the aerospace community, the NASA program chose hydrazine arcjets for development. A joint government/industry development program ensued which culminated in the acceptance of arcjet technology. NASA efforts included fundamental feasibility assessments, hardware development and verification, and multiple efforts aimed at the demonstration of critical operational characteristics of arcjet systems. Throughout the program, constant contact with the user community was maintained to determine system requirements. Both contracted and cooperative programs with industry were supported. First generation, kW-class arcjets are now operational for NSSK on the Telstar 401 satellite launched in December of 1993 and are baselined for use on multiple future satellite series (Intelsat 8, AsiaSat, Echostar). Arcjet development efforts are now focusing on the development of both high performance (600 s), 2 kW thrusters for application on next generation comsats and low power (Pe approximately 0.5 kW) for a variety of applications on power limited satellites. This paper presents a review of the NASA's role in the development of hydrazine arcjets with a focus on approaches, lessons learned, and the future.

Curren, Francis M.↗
NASA NTRS1976

LSSA (Low-cost Silicon Solar Array) project

Methods are explored for economically generating electrical power to meet future requirements. The Low-Cost Silicon Solar Array Project (LSSA) was established to reduce the price of solar arrays by improving manufacturing technology, adapting mass production techniques, and promoting user acceptance. The new manufacturing technology includes the consideration of new silicon refinement processes, silicon sheet growth techniques, encapsulants, and automated assembly production being developed under contract by industries and universities.

Source record↗
NASA NTRS1997

Rhenium Rocket Manufacturing Technology

The NASA Lewis Research Center's On-Board Propulsion Branch has a research and technology program to develop high-temperature (2200 C), iridium-coated rhenium rocket chamber materials for radiation-cooled rockets in satellite propulsion systems. Although successful material demonstrations have gained much industry interest, acceptance of the technology has been hindered by a lack of demonstrated joining technologies and a sparse materials property data base. To alleviate these concerns, we fabricated rhenium to C-103 alloy joints by three methods: explosive bonding, diffusion bonding, and brazing. The joints were tested by simulating their incorporation into a structure by welding and by simulating high-temperature operation. Test results show that the shear strength of the joints degrades with welding and elevated temperature operation but that it is adequate for the application. Rhenium is known to form brittle intermetallics with a number of elements, and this phenomena is suspected to cause the strength degradation. Further bonding tests with a tantalum diffusion barrier between the rhenium and C-103 is planned to prevent the formation of brittle intermetallics.

Source record↗
NASA NTRS1996

Advanced Failure Determination Measurement Techniques Used in Thermal Fatigue Life Testing of Electronic Packaging

Thermal fatigue life testing of various electronic packaging technologies is being performed by the Reliability Technology Group at the Jet Propulsion Laboratory. These testing efforts are in progress to improve uderstanding of the reliability issues associated with low volume packaging technologies for space applications and to develop qualification and acceptance approaches for these technologies. The work described here outlines the electrical failure detection techniques used during testing by documenting the circuits and components used to make these measurements, the sensitivity of the measurements, and the applicability of each specific measurement.

fatigue surface mount measurement testing thermal ↗
NASA NTRS1994

Automatic translation among spoken languages

The Machine Aided Voice Translation (MAVT) system was developed in response to the shortage of experienced military field interrogators with both foreign language proficiency and interrogation skills. Combining speech recognition, machine translation, and speech generation technologies, the MAVT accepts an interrogator's spoken English question and translates it into spoken Spanish. The spoken Spanish response of the potential informant can then be translated into spoken English. Potential military and civilian applications for automatic spoken language translation technology are discussed in this paper.

Walter, Sharon M.↗
NASA NTRS1987

A view from the AIAA: Introduction of new energy storage technology into orbital programs

The development of new energy storage technology must be heavily weighted toward the application. The requirements for transitioning low risk technology into operational space vehicles must remain the central theme even at the preliminary development stages by the development of efforts to define operational issues and verify the reliability of the system. Failure to follow a complete plan that results in a flight qualified unit may lead to an orphan technology. Development efforts must be directed toward a stable development where changes in design are evolutionary and end items are equivalent to flight units so that life and qualification testing can be used as a vehicle to demonstrate the acceptability of the technology.

Badcock, Charles↗
NASA NTRS2014

Cutting More than Metal: Breaking the Development Cycle

New technology is changing the way we do business at NASA. The ability to use these new tools is made possible by a learning culture able to embrace innovation, flexibility, and prudent risk tolerance, while retaining the hard-won lessons learned of other successes and failures. Technologies such as 3-D manufacturing and structured light scanning are re-shaping the entire product life cycle, from design and analysis, through production, verification, logistics and operations. New fabrication techniques, verification techniques, integrated analysis, and models that follow the hardware from initial concept through operation are reducing the cost and time of building space hardware. Using these technologies to be more efficient, reliable and affordable requires we bring them to a level safe for NASA systems, maintain appropriate rigor in testing and acceptance, and transition new technology. Maximizing these technologies also requires cultural acceptance and understanding and balancing rules with creativity. Evolved systems engineering processes at NASA are increasingly more flexible than they have been in the past, enabling the implementation of new techniques and approaches. This paper provides an overview of NASA Marshall Space Flight Center's new approach to development, as well as examples of how that approach has been incorporated into NASA's Space Launch System (SLS) Program, which counts among its key tenants - safety, affordability, and sustainability. One of the 3D technologies that will be discussed in this paper is the design and testing of various rocket engine components.

Singer, Chris↗