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NASA NTRS1987

Advanced liquid-cooled, turbocharged and intercooled stratified charge rotary engines for aircraft

Developments concerning stratified-charge rotary (SCR) engines over the past 10 years are reviewed. Aircraft engines being developed using SCR technology are shown and described, and the ability of such technology to meet general aviation engine needs is considered. Production timing and availability of SCR technology for the development of aviation rotary engines are discussed, and continuing efforts toward improving this technology, including NASA efforts, are described.

Mount, Robert E.↗

NASA NTRS1987

NASA's Earth Resources Laboratory - Seventeen years of using remotely sensed satellite data in land applications

The activities of the Earth Resources Laboratoy (ERL) for the past seventeen years are reviewed with particular reference to four typical applications demonstrating the use of remotely sensed data in a geobased information system context. The applications discussed are: a fire control model for the Olympic National Park; wildlife habitat modeling; a resource inventory system including a potential soil erosion model; and a corridor analysis model for locating routes between geographical locations. Some future applications are also discussed.

Cashion, Kenneth D.↗

NASA NTRS1988

Getting ready to go

The reevaluation of the Space Station that has occurred over the past two and a half years is reviewed, and the system development that has been recently initiated is discussed. Upcoming developments with regard to laboratory outfitting, extended duration Orbiter, and logistics operations are summarized. The goals of the first launches are discussed, and the aims of the succeeding manned flights are examined.

Moser, Thomas L.↗

NASA NTRS1988

Fifty years of laminar flow flight testing

Laminar flow flight experiments conducted over the past 50 years are reviewed. The emphasis is on flight testing conducted under the NASA Laminar Flow Control Program, which has been directed towards the most challenging technology application, the high-subsonic-speed transport. The F111/TACT NLF Glove Flight Test, the F-14 Variable-Sweep Transition Flight Experiment, the 757 Wing-Noise Survey and NLF Glove Flight Test, the NASA Jetstar Leading-Edge Flight Test Program, and the recently initiated Hybrid Laminar-Flow-Control Flight Experiment are discussed.

Wagner, R. D.↗

NASA NTRS1989

NASA/USRA University advanced design program

The participation of the University of Illinois at Urbana-Champaign in the NASA/USRA University Advanced Design Program for the 1988 to 1989 academic year is reviewed. The University's design project was the Logistics Resupply and Emergency Crew Return System for Space Station Freedom. Sixty-one students divided into eight groups, participated in the spring 1989 semester. A presentation prepared by three students and a graduate teaching assistant for the program's summer conference summarized the project results. Teamed with the NASA Marshall Space Flight Center (MSFC), the University received support in the form of remote telecon lectures, reference material, and previously acquired applications software. In addition, a graduate teaching assistant was awarded a summer 1989 internship at MSFC.

Lembeck, Michael F.↗

NASA NTRS1990

30 years of adaptive neural networks - Perceptron, Madaline, and backpropagation

Fundamental developments in feedforward artificial neural networks from the past thirty years are reviewed. The history, origination, operating characteristics, and basic theory of several supervised neural-network training algorithms (including the perceptron rule, the least-mean-square algorithm, three Madaline rules, and the backpropagation technique) are described. The concept underlying these iterative adaptation algorithms is the minimal disturbance principle, which suggests that during training it is advisable to inject new information into a network in a manner that disturbs stored information to the smallest extent possible. The two principal kinds of online rules that have developed for altering the weights of a network are examined for both single-threshold elements and multielement networks. They are error-correction rules, which alter the weights of a network to correct error in the output response to the present input pattern, and gradient rules, which alter the weights of a network during each pattern presentation by gradient descent with the objective of reducing mean-square error (averaged over all training patterns).

Widrow, Bernard↗

NASA NTRS1991

Overview of the SP-100 Program

Technical progress made by the SP-100 Program over the past five years is reviewed. The following advances are discussed: (1) development of the fuel pin which is the thermal power producing component in the system; (2) development of the conductively coupled multi-couple thermoelectric cell components; (3) verification of the predicted structural and electrical performance of the thermoelectric cells; (4) development of fabricating and welding niobium alloy, NblZr and NblZr.1C to verify the containment of lithium in space vacuum with no leakage, (5) the containment of nitrogen in the fuel with accurate stoichiometric control and bonded rhenium liners, (6) system mass reduction of 15 percent; and (7) the development of high-temperature, low-cost, low-mass heat pipes for heat rejection to space.

Mondt, Jack F.↗

NASA NTRS1992

Development and flight history of SERT 2 spacecraft

A 25-year historical review of the Space Electric Rocket Test 2 (SERT 2) mission is presented. The Agena launch vehicle; the SERT 2 spacecraft; and mission-peculiar spacecraft hardware, including two ion thruster systems, are described. The 3 1/2-year development period, from 1966 to 1970, that was needed to design, fabricate, and qualify the ion thruster system and the supporting spacecraft components, is documented. Major testing of two ion thruster systems and related auxiliary experiments that were conducted in space after the 3 Feb. 1970, launch are reviewed. Extended ion thruster restarts from 1973 to 1981 are reported, in addition to cross-neutralization tests. Tests of a reflector erosion experiment were continued in 1989 to 1991. The continuing performance of spacecraft subsystems, including the solar arrays, over the 1970-1991 period is summarized. Finally, the knowledge of thruster-spacecraft interactions learned from SERT 2 is listed.

Kerslake, William R.↗

NASA NTRS1992

Development and flight history of SERT 2 spacecraft

A 25-year historical review of the Space Electric Rocket Test 2 (SERT 2) mission is presented. The Agena launch vehicle; the SERT 2 spacecraft; and mission-peculiar spacecraft hardware, including two ion thruster systems are described. The 3 1/2-year development period, from 1966 to 1970, that was needed to design, fabricate, and qualify the ion thruster system and the supporting spacecraft components, is documented. Major testing of two ion thruster systems and related auxiliary experiments that were conducted in space after the 3 Feb. 1970, launch are reviewed. Extended ion thruster restarts from 1973 to 1981 are reported, in addition to cross-neutralization tests. Tests of a reflector erosion experiment were continued in 1989 to 1991. The continuing performance of spacecraft subsystems, including the solar arrays, over the 1970-1991 period is summarized. Finally, the knowledge of thruster-spacecraft interactions learned from SERT 2 is listed.

Kerslake, William R.↗

NASA NTRS1995

Effects of Meteoroid Erosion in Planetary Rings

This grant supported continuing studies of the effects of ballistic transport on the evolution of Saturn's rings. Ballistic transport, as used in this context, refers to the net transport of mass and angular momentum caused by the exchange of meteoroid impact ejecta between neighboring ring regions (Ip 1983, 1984, Morfill et al. 1983, Lissauer 1984, Durisen 1984a,b). The characteristic time scale associated with this process is the gross erosion time t(sub g) the time it would take a ring region to be completed eroded if all impact ejecta were lost. This time scale is estimated to be about 10(exp 5) to 10(exp 6) years for a ring region with normal optical depth tau approximately 1. Earlier work by myself and collaborators developed the physical theory and simulation techniques to model this process (Durisen et al. 1989, Cuzzi and Durisen 1990). Detailed simulations, supported in part by this grant, have demonstrated that ballistic transport can produce observed structures in Saturn's rings, especially at and near the inner edges of the A and B Rings (Durisen et al. 1992, 1996). The structures of interest in the real rings are illustrated in Figures 1 and 2. Most of these structures were previously unexplained. The computational results plus analytic treatments place useful constraints on fundamental ring properties, including the indication of a relatively young ring age less than or equal 10(exp 8) years (see reviews by Nicholson and Dones 1991, Esposito 1993, Cuzzi 1995, and Porco 1995). This grant also supported development of the faster computational algorithms necessary to permit longer evolutions. Resulting simplications in the ballistic transport equations permitted an analytic linear stability analysis (Durisen 1995), which has provided considerable insight into ballistic transport processes and applications to Saturn's rings. All these accomplishments are described in more detail below.

Durisen, Richard H.↗

NASA NTRS1996

Solar energetic particle events: Statistical modelling and prediction

Solar energetic particle events (SEPEs) can have a significant effect on the design and operation of earth orbiting and interplanetary spacecraft. In relation to this, the calculation of proton fluences and fluxes are considered, describing the current state of the art in statistical modeling. A statistical model that can be used for the estimation of integrated proton fluences for different mission durations of greater than one year is reviewed. The gaps in the modeling capabilities of the SEPE environment, such as a proton flux model, alpha particle and heavy ion models and solar cycle variations are described together with the prospects for the prediction of events using neural networks.

Gabriel, S. B.↗

NASA NTRS1997

Verification and Improvement of Flamelet Approach for Non-Premixed Flames

Studies in the mathematical modeling of the high-speed turbulent combustion has received renewal attention in the recent years. The review of fundamentals, approaches and extensive bibliography was presented by Bray, Libbi and Williams. In order to obtain accurate predictions for turbulent combustible flows, the effects of turbulent fluctuations on the chemical source terms should be taken into account. The averaging of chemical source terms requires to utilize probability density function (PDF) model. There are two main approaches which are dominant in high-speed combustion modeling now. In the first approach, PDF form is assumed based on intuitia of modelliers (see, for example, Spiegler et.al.; Girimaji; Baurle et.al.). The second way is much more elaborate and it is based on the solution of evolution equation for PDF. This approach was proposed by S.Pope for incompressible flames. Recently, it was modified for modeling of compressible flames in studies of Farschi; Hsu; Hsu, Raji, Norris; Eifer, Kollman. But its realization in CFD is extremely expensive in computations due to large multidimensionality of PDF evolution equation (Baurle, Hsu, Hassan).

Zaitsev, S.↗

NASA NTRS1998

Life and Microgravity Spacelab (LMS)

This document reports the results and analyses presented at the Life and Microgravity Spacelab One Year Science Review meeting. The science conference was held in Montreal, Canada, on August 20-21, 1997, and was hosted by the Canadian Space Agency. The LMS payload flew on the Space Shuttle Columbia (STS-78) from June 20 - July 7, 1996. The LMS investigations were performed in a pressurized Spacelab module and the Shuttle middeck. Forty scientific experiments were performed in fields such as fluid physics, solidification of metals, alloys, and semiconductors, the growth of protein crystals, and animal, human, and plant life sciences. The results demonstrate the range of quality science that can be conducted utilizing orbital laboratories in microgravity.

Downey, James Patton↗

NASA NTRS1997

34th JANNAF Combustion Subcommittee Meeting: MURI Technology - Volume 2

This volume is a compilation of 48 unclassified/unlimited distribution papers presented at the 1997 meeting of the JANNAF 34th Combustion Subcommittee (CS) held jointly with the Propulsion Systems Hazards Subcommittee (PSHS), and the Airbreathing Propulsion Subcommittee. Proceedings of the CS, PSHS and APS meetings are published separately by CPIA. The CS Meeting Proceedings are published in four volumes. The JANNAF papers contained in this volume contributed to the Second Year Progress Review of the Multidisciplinary University Research Initiative Program (MURI) on 'Novel New Ingredients to Stabilize Rocket Motors'. Technical progress made on this program was presented as JANNAF CS papers contained in Volumes 2 and 4. Papers contained in this volume review bi-plateau propellant combustion, AP and metal combustion, solid propellant combustion instability fundamentals and motor applications, gas-phase and condensed-phase kinetics, and measurement techniques.

Fry, Ronald S.↗

NASA NTRS1998

Journey in Aeronautical Research: A Career at NASA Langley Research Center: Monographs in Aerospace History - No. 12

An autobiography, of a noted aeronautical engineer, W. Hewitt Phillips, whose career spanned 58 years (1940-1998) at NASA Langley is presented. This work covers his early years to the Sputnik launch. His interests have been in research in aeronautics and in the related problems of spaceflight. After an introduction, his early life through the college years is reviewed, and his early interest in model airplanes is described. The first assignment for the National Advisory Committee for Aeronautics (NACA), which would later become NASA, was with the Flight Research Division. His early work involved "Flying Qualities", i.e., the stability and control characteristics of an airplane. The next chapter describes his early analytical studies. His work during World War II in the design of military airplanes, and the other effects of the war on research activities, is covered in the next two chapters. This research was involved in such innovations and refinements as the swept wing, the flettner tabs, servo tabs, spring tabs and whirlerons. The rest of the work covers the research which Mr. Hewitt was involved in, after the war until the Sputnik launch. These areas include unsteady lift, measurements of turbulence in the atmosphere, gust alleviation, and lateral response to random turbulence. He was also involved in several investigations of airplane accidents. The last two chapters cover the administration of the Langley Research Center, and the dawn of the Space Age. A complete bibliography of reports written by Mr. Hewitt, is included.

Phillips, W. Hewitt↗

NASA NTRS2000

Evaluating Education and Science in the KSC Visitor Complex Exhibits

The continuing development of exhibits at the Kennedy Space Center's Visitor Complex is an excellent opportunity for NASA personnel to promote science and provide insight into NASA programs and projects for the approximately 3 million visitors that come to KSC annually. Stated goals for the Visitor Complex, in fact, emphasize science awareness and recommend broadening the appeal of the displays and exhibits for all age groups. To this end, this summer project seeks to evaluate the science content of planned exhibits/displays in relation to these developing opportunities and identify specific areas for enhancement of existing or planned exhibits and displays. To help expand the educational and science content within the developing exhibits at the Visitor Complex, this project was structured to implement the goals of the Visitor Center Director. To accomplish this, the exhibits and displays planned for completion within the year underwent review and evaluation for science content and educational direction. Planning emphasis for the individual displays was directed at combining the elements of effective education with fundamental scientific integrity, within an appealing format.

Erickson, Lance K.↗

NASA NTRS2001

Recent Developments in U.S. Engine Noise Reduction Research

Aircraft engine noise research in the United States has made considerable progress over the past 10 years for both subsonic and supersonic flight applications. The Advanced Subsonic Technology (AST) Noise Reduction Program started in 1994 and will be completed in 2001 without major changes to program plans and funding levels. As a result, significant progress has been made toward the goal of reducing engine source noise by 6 EPNdB (Effective Perceived Noise level in decibels). This paper will summarize some of the significant accomplishments from the subsonic engine noise research performed over the past 10 years. The review is by no means comprehensive and only represents a sample of major accomplishments.

Bridges, James↗

NASA NTRS2003

Evaluating Behaviorally Oriented Aviation Maintenance Resource Management (MRM) Training and Programs: Methods, Results, and Conclusions

Assessment of the impact of Aviation Resource Management Programs on aviation culture and performance has compelled a considerable body of research (Taylor & Robertson, 1995; Taylor, 1998; Taylor & Patankar, 2001). In recent years new methods have been applied to the problem of maintenance error precipitated by factors such as the need for self-assessment of communication and trust. The present study - 2002 -- is an extension of that past work. This research project was designed as the conclusion of a larger effort to help understand, evaluate and validate the impact of Maintenance Resource Management (MRM) training programs, and other MRM interventions on participant attitudes, opinions, behaviors, and ultimately on enhanced safety performance. It includes research and development of evaluation methodology as well as examination of psychological constructs and correlates of maintainer performance. In particular, during 2002, three issues were addressed. First, the evaluation of two (independent & different) MRM programs for changing behaviors was undertaken. In one case we were able to further apply the approach to measuring written communication developed during 2001 (Taylor, 2002; Taylor & Thomas, 2003). Second, the MRM/TOQ surveys were made available for completion on the internet. The responses from these on-line surveys were automatically linked to a results calculator (like the one developed and described in Taylor, 2002) to aid industry users in analyzing and evaluating their local survey data on the internet. Third, the main trends and themes from our research about MRM programs over the past dozen years were reviewed.

Taylor, James C.↗