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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 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1929

Investigation of damping liquids for aircraft instruments

This report covers the results of an investigation carried on at the Bureau of Standards under a research authorization from, and with the financial assistance of, the National Advisory Committee for Aeronautics. The choice of a damping liquid for aircraft instruments is difficult owing to the range of temperature at which aircraft operate. Temperature changes affect the viscosity tremendously. The investigation was undertaken with the object of finding liquids of various viscosities otherwise suitable which had a minimum change in viscosity with temperature. The new data relate largely to solutions. The effect of temperature on the kinematic viscosity of the following liquids and solutions was determined in the temperature interval -18 degrees to +30 degrees C. (1) solutions of animal and vegetable oils in xylene. These were poppy-seed oil, two samples of neat's-foot oils, castor oil, and linseed oil. (2) solutions of mineral oil in xylene. These were Squibb's petrolatum of naphthene base and transformer oil. (3) glycerine solutions in ethyl alcohol and in mixture of 50-50 ethyl alcohol and water. (4) mixtures of normal butyl alcohol with methyl alcohol. (5) individual liquids, kerosene, mineral spirits, xylene, recoil oil. The apparatus consisted of four capillary-tube viscometers, which were immersed in a liquid bath in order to secure temperature control. The method of calibration and the related experimental data are presented.

Keulegan, G H↗
NASA NTRS1982

A Record of NASA Space Missions Since 1958

Dedicated men and women together with a unique team of industries and universities created the U.S. space program. They provided the ideas, developed the hardware, launched the satellites, safely returned our astronauts, and successfully retrieved hard-won data from outer space. In an attempt to document, between two covers, the accomplishments of the 1958-1981 period, this report has been compiled. It is a record of an exciting and often dramatic period in the history of the United States. The National Aeronautic and Space Administration is proud to have been permitted to play such an important role in challenging man's spirit.

Rosenthal, Alfred↗
NASA NTRS1992

Headquarters summary reports

The status is summarized of the NASA sponsored involvement in high speed civil transport research and technology, including major cooperative efforts. That involvement is currently focussed on the High Speed Research Program. The program goals are an acceptable level of ozone depletion or sonic boom, the definition of which is a regulatory and political process. The HSRP goal is to provide technical bases for acceptability criteria. Community noise is currently regulated, and it seems clear that HSCT aircraft will have to comply with at least the spirit of the current subsonic constraint, FAR 36, Stage 3.

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NASA NTRS1992

Perspectives from space: NASA classroom information and activities

This booklet contains the information and classroom activities included on the backs of the eight poster series, 'Perspectives From Space'. The first series, Earth, An Integrated System, contains information on global ecology, remote sensing from space, data products, earth modeling, and international environmental treaties. The second series, Patterns Among Planets, contains information on the solar system, planetary processes, impacts and atmospheres, and a classroom activity on Jupiter's satellite system. The third series, Our Place In The Cosmos, contains information on the scale of the universe, origins of the universe, mission to the universe, and three classroom activities. The fourth series, Our Sun, The Nearest Star, contains information on the Sun. The fifth series, Oasis Of Life, contains information on the development of life, chemical and biological evolution on Earth and the search for other life in the universe. The sixth series, The Influence Of Gravity, contains information on Newton's Law of Gravity, space and microgravity, microgravity environment, and classroom activities on gravity. The seventh series, The Spirit Of Exploration, contains information on space exploration, the Apollo Program, future exploration activities, and two classroom activities. The eighth series, Global Cooperation, contains information on rocketry, the space race, and multi-nation exploration projects.

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NASA NTRS1994

The 21St JANNAF Exhaust Plume Technology Meeting

This volume, the first of three volumes, is a collection of 10 unclassified/unlimited papers which were presented at the 21st Joint Army-Navy-NASA-Air Force (JANNAF) Exhaust Plume Technology Subcommittee Meeting in conjunction with the Combustion Subcommittee and SPIRITS User Group Meeting held 19-21 October 1994 at the Lockheed Missiles and Space Company, Sunnyvale, California. Specific subjects discussed include behavior of aluminum and aluminum oxide in solid rocket plumes, exhaust plume flowfield characterization and plume phenomena at high altitudes.

Gannaway, Mary T.↗
NASA NTRS1994

31st JANNAF Combustion Subcommittee Meeting

This volume, the first of our volumes, is a collection of 32 unclassified/unlimited papers which were presented at the 31st Joint Army-Navy-NASA-Air Force (JANNAF) Combustion Subcommittee Meeting in conjunction with the Exhaust Plume Technology Subcommittee and SPIRITS User Group Meeting held 17-21 October 1994 at the Lockheed Missiles and Space Company, Sunnyvale, California. Specific subjects discussed include: combustion characteristics of metallized solids in nozzles and plumes; airbreathing propulsion; advanced and electrothermal-chemical guns; gun propellant ignition and interior ballistics; liquid propellant guns; liquid propellant combustion and combustion oscillation and liquid rocket engine combustion.

Gannaway, Mary T.↗
NASA NTRS1994

31st JANNAF Combustion Subcommittee Meeting

This volume, the second of four volumes, is a collection of 36 unclassified/unlimited papers which were presented at the 31st Joint Army-Navy-NASA-Air Force (JANNAF) Combustion Subcommittee Meeting in conjunction with the Exhaust Plume Technology Subcommittee and SPIRITS User Group Meeting held 17-21 October 1994 at the Lockheed Missiles and Space Company, Sunnyvale, California. Specific subjects discussed include solid propellant combustion instability and unsteady combustion, rocket motors, guns and marine combustion characteristics, solid propellant formulation and solid and gas phase combustion kinetics.

Gannaway, Mary T.↗
NASA NTRS1994

Reionization in a cold dark matter universe: The feedback of galaxy formation on the intergalactic medium

We study the coupled evolution of the intergalactic medium (IGM) and the emerging structure in the universe in the context of the cold dark matter (CDM) model, with a special focus on the consequences of imposing reionization and the Gunn-Peterson constraint as a boundary condition on the model. We have calculated the time-varying density of the IGM by coupling our detailed, numerical calculations of the thermal and ionization balance and radiative transfer in a uniform, spatially averaged IGM of H and He, including the mean opacity of an evolving distribution of gas clumps which correspond to quasar absorption line clouds, to the linearized equations for the growth of density fluctuations in both the gaseous and dark matter components in a CDM universe. We use the linear growth equations to identify the fraction of the gas which must have collapsed out at each epoch, an approach similar in spirit to the so-called Press-Schechter formalism. We identify the IGM density with the uncollapsed baryon fraction. The collapsed fraction is postulated to be a source of energy injection into the IGM, by radiation or bulk hydrodynamical heating (e.g., via shocks) or both, at a rate which is marginally enough to satisfy the Gunn-Peterson constraint at z less than 5. Our results include the following: (1) We find that the IGM in a CDM model must have contained a substantial fraction of the total baryon density of the universe both during and after its reionization epoch. (2) As a result, our previous conclusion that the observed Quasi-Stellar Objects (QSOs) at high redshift are not sufficient to ionize the IGM enough to satisfy the Gunn-Peterson constraint is confirmed. (3) We predict a detectable He II Gunn-Peterson effect at 304(1 + z) A in the spectra of quasars at a range of redshift z greater than or approx. 3, depending on the nature of the sources of IGM reionization. (4) We find, moreover, that a CDM model with high bias parameter b (i.e., b greater than or approx. 2) cannot account for the baryon content of the universe at z approximately 3 observed in quasar absorption line gas unless Omega (sub B) significantly exceeds the maximum value allowed by big bang nucleocynthesis. (5) For a CDM model with bias parameter within the allowed range of (lower) values, the lower limit to Omega(sub B) imposed by big bang nucleosynthesis (Omega(sub B) h(sup 2) greater than or equal to 0.01) combines with our results to yield the minimum IGM density for the CDM fodel. For CDM with b = 1 (Cosmic Background Explorer (COBE) normalization), we find Omega(sub IGM)(sup min) (z approximately 4) approx. equal 0.02-0.03, and Omega(sub IGM)(sup min)(z approximately 0) approx. equal 0.005-0.03, depending upon the nature of the sources of IGM reionization. (6) In general, we find that self-consistent reionization of the IGM by the collapsed baryon fraction has a strong effect on the rate of collapse. (7) As a further example, we show that the feedback effect on the IGM of energy release by the collapsed baryon fraction may explain the slow evolution of the observed comoving QSO number density between z = 5 and z = 2, followed by the sharp decline after z = 2.

Shapiro, Paul R.↗
NASA NTRS1993

A high accuracy sequential solver for simulation and active control of a longitudinal combustion instability

A high accuracy convection scheme using a sequential solution technique has been developed and applied to simulate the longitudinal combustion instability and its active control. The scheme has been devised in the spirit of the Total Variation Diminishing (TVD) concept with special source term treatment. Due to the substantial heat release effect, a clear delineation of the key elements employed by the scheme, i.e., the adjustable damping factor and the source term treatment has been made. By comparing with the first-order upwind scheme previously utilized, the present results exhibit less damping and are free from spurious oscillations, offering improved quantitative accuracy while confirming the spectral analysis reported earlier. A simple feedback type of active control has been found to be capable of enhancing or attenuating the magnitude of the combustion instability.

Shyy, W.↗
NASA NTRS1994

Minimum fuel lunar trajectories for a low-thrust power-limited spacecraft

Minimum fuel trajectories from a low Earth parking orbit to a low Moon orbit are obtained for a low-thrust power-limited spacecraft with thrust acceleration levels of the order of 10(exp -3) G. The trajectories are found by matching an Earth spiral to a Moon spirit at some intermediate distance. Results are given for the planar case and for the three dimensional case where the Moon orbit is polar.

Golan, Oded M.↗
NASA NTRS1993

Sines and Cosines. Part 2 of 3

The Law of Sines and the Law of Cosines are introduced and demonstrated in this 'Project Mathematics' series video using both film footage and computer animation. This video deals primarily with the mathematical field of Trigonometry and explains how these laws were developed and their applications. One significant use is geographical and geological surveying. This includes both the triangulation method and the spirit leveling method. With these methods, it is shown how the height of the tallest mountain in the world, Mt. Everest, was determined.

Apostol, Tom M.↗
NASA NTRS1995

The 32nd JANNAF Combustion Subcommittee and 1995 Propulsion Systems Hazards Subcommittee Meeting: Joint Sessions - Volume 1

This volume, the first of two volumes, is a collection of 18 unclassified/unlimited papers which were presented at the 32nd Joint Army-Navy-NASA-Air Force (JANNAF) Combustion Subcommittee Meeting in conjunction with the Propulsion Systems Hazards Subcommittee, the 22nd Exhaust Plume Technology Subcommittee, the 4th SPIRITS User Group Meeting and the Pennsylvania State University 7th Propulsion Engineering Research Center (PERC) Symposium held 23-27 October 1995 at the NASA Marshall Space Flight Center, Huntsville, AL. The JANNAF papers contained in this volume reviewed solid propellant thermal decomposition, combustion of nitramine ingredients and ignition/combustion of new energetic ingredients and nitramine propellants.

Fry, Ronald S.↗
NASA NTRS1995

An Extended Lagrangian Method

A unique formulation of describing fluid motion is presented. The method, referred to as 'extended Lagrangian method,' is interesting from both theoretical and numerical points of view. The formulation offers accuracy in numerical solution by avoiding numerical diffusion resulting from mixing of fluxes in the Eulerian description. The present method and the Arbitrary Lagrangian-Eulerian (ALE) method have a similarity in spirit-eliminating the cross-streamline numerical diffusion. For this purpose, we suggest a simple grid constraint condition and utilize an accurate discretization procedure. This grid constraint is only applied to the transverse cell face parallel to the local stream velocity, and hence our method for the steady state problems naturally reduces to the streamline-curvature method, without explicitly solving the steady stream-coordinate equations formulated a priori. Unlike the Lagrangian method proposed by Loh and Hui which is valid only for steady supersonic flows, the present method is general and capable of treating subsonic flows and supersonic flows as well as unsteady flows, simply by invoking in the same code an appropriate grid constraint suggested in this paper. The approach is found to be robust and stable. It automatically adapts to flow features without resorting to clustering, thereby maintaining rather uniform grid spacing throughout and large time step. Moreover, the method is shown to resolve multi-dimensional discontinuities with a high level of accuracy, similar to that found in one-dimensional problems.

Liou, Meng-Sing↗
NASA NTRS1997

Global Positioning System Antenna Fixed Height Tripod Adapter

An improved Global Positioning em antenna adaptor allows fixed antenna height measurements by removably attaching an adaptor plate to a conventional surveyor's tripod. Antenna height is controlled by an antenna boom which is a fixed length rod. The antenna is attached to one end of the boom. The opposite end of the boom tapers to a point sized to fit into a depression at the center of survey markers. The boom passes through the hollow center of a universal ball joint which is mounted at the center of the adaptor plate so that the point of the rod can be fixed in the marker's central depression. The mountains of the ball joint allow the joint to be moved horizontally in any direction relative to the tripod. When the ball joint is moved horizontally, the angle between the boom and the vertical changes because the boom's position is fixed at its lower end. A spirit level attached to the rod allows an operator to determine when the boom is plumb. The position of the ball joint is adjusted horizontally until the boom is plumb. At that time the antenna is positioned exactly over the center of the monument and the elevation of the antenna is precisely set by the length of the boom.

Dinardo, Steven J.↗
NASA NTRS1995

Modified Interior Distance Functions (Theory and Methods)

In this paper we introduced and developed the theory of Modified Interior Distance Functions (MIDF's). The MIDF is a Classical Lagrangian (CL) for a constrained optimization problem which is equivalent to the initial one and can be obtained from the latter by monotone transformation both the objective function and constraints. In contrast to the Interior Distance Functions (IDF's), which played a fundamental role in Interior Point Methods (IPM's), the MIDF's are defined on an extended feasible set and along with center, have two extra tools, which control the computational process: the barrier parameter and the vector of Lagrange multipliers. The extra tools allow to attach to the MEDF's very important properties of Augmented Lagrangeans. One can consider the MIDFs as Interior Augmented Lagrangeans. It makes MIDF's similar in spirit to Modified Barrier Functions (MBF's), although there is a fundamental difference between them both in theory and methods. Based on MIDF's theory, Modified Center Methods (MCM's) have been developed and analyzed. The MCM's find an unconstrained minimizer in primal space and update the Lagrange multipliers, while both the center and the barrier parameter can be fixed or updated at each step. The MCM's convergence was investigated, and their rate of convergence was estimated. The extension of the feasible set and the special role of the Lagrange multipliers allow to develop MCM's, which produce, in case of nondegenerate constrained optimization, a primal and dual sequences that converge to the primal-dual solutions with linear rate, even when both the center and the barrier parameter are fixed. Moreover, every Lagrange multipliers update shrinks the distance to the primal dual solution by a factor 0 less than gamma less than 1 which can be made as small as one wants by choosing a fixed interior point as a 'center' and a fixed but large enough barrier parameter. The numericai realization of MCM leads to the Newton MCM (NMCM). The approximation for the primal minimizer one finds by Newton Method followed by the Lagrange multipliers update. Due to the MCM convergence, when both the center and the barrier parameter are fixed, the condition of the MDF Hessism and the neighborhood of the primal ninimizer where Newton method is 'well' defined remains stable. It contributes to both the complexity and the numerical stability of the NMCM.

Polyak, Roman A.↗
NASA NTRS1997

Center of Excellence in Model-Based Human Performance

The Center of Excellence (COE) was created in 1984 to facilitate active collaboration between the scientists at Ames Research Center and the Stanford Psychology Department. As this document will review, over that period of time, the COE served its function well. Funds from the Center supported a large number of projects over the last ten years. Many of the people who were supported by the Center Have gone on to distinguished research careers in government, industry and university. In fact, several of the people currently working at NASA Ames were initially funded by the Center mechanism, which served as a useful vehicle for attracting top quality candidates and supporting their research efforts. We are grateful for NASA's support over the years. As we reviewed in the reports for each year, the COE budget generally provided a portion of the true costs of the individual research project. Hence, the funds from the COE were leveraged with funds from industry and other government agencies. In this way, we feel that all parties benefitted greatly from the collaborative spirit and interactive aspects of the COE. The portion of the support from NASA was particularly important in helping members of the COE to set aside the time to publish papers and communicate advances in our understanding of human performance in NASA-related missions.

Wandell, Brian A.↗
NASA NTRS1997

School Science Comes Alive

Phase 3 of the School Science Comes Alive Program (S(sup 2)CAP) created an exciting, science - enrichment experience for third, fourth and fifth graders and their teachers and enhanced the science-teaching skills of teacher teams at each of four participating elementary schools on Virginia's Peninsula. The schools involved enroll a majority of Black students, many of whom are from economically disadvantaged households. Designed to build on the highly successful S(sup 2)CAP program of the preceding two years, this project brought college faculty together with classroom teachers and trained volunteers in a cooperative effort to make a lasting difference in the quality of science education at the four schools. In total, this program touched approximately 1000 the school children, more than half of whom are black, giving them direct and indirect exposure to the spirit of inquiry and adventure of the world-wide science community. In S(sup 2)CAP Phase 3, a large measure of responsibility was placed on the classroom teachers, thus creating a more sustainable partnership between college faculty and grade school teacher. Our college physics professors coached and supported teams of teachers from each school at intensive training workshops. A volunteer program provided each teacher with one or more trained volunteers to assist in class with the hands-on activities that have been central to the S2CAP program. Most of the equipment for these activities was constructed during the workshops by the teachers and volunteers from low cost materials provided by the program. Two types of volunteers were enlisted: science smart black college students and technically trained retirees (many of whom are ex-NASA employees). One goal of this program was to increase the numbers of minority students who see science as an interesting and exciting subject, to make the science period a time which students look forward to in the school day. Such an attitude is expected to translate naturally into a higher interest in science and engineering as a career for these students. A second goal was to create a sustainable improvement in the way science is taught at the elementary level. By the end of the program we expected that our teachers would be significantly more self reliant in using hands-on-activities as a part of their science curricula than they were prior to their involvement with S2CAP. In summary, S2CAP Phase 3 offered intensive training workshops for teachers and supporting volunteers followed by stimulating hands-on activities in the classroom for the children. These components combined to amplify the experience, enthusiasm, and ideas of our scientists in a way that complements the normal elementary school curriculum in each of the two school systems involved.

Hartline, Frederick F.↗
NASA NTRS1997

Center of Excellence in Model-Based Human Performance

The Center of Excellence (COE) was created in 1984 to facilitate active collaboration between the scientists at Ames Research Center and the Stanford Psychology Department. As this document will review, over that period of time, the COE served its function well. Funds from the Center supported a large number of projects over the last ten years. Many of the people who were supported by the Center have gone on to distinguished research careers in government, industry and university. In fact, several of the people currently working at NASA Ames were initially funded by the Center mechanism, which served as a useful vehicle for attracting top quality candidates and supporting their research efforts. We are grateful for NASA's support over the years. As we reviewed in the reports for each year, the COE budget generally provided a portion of the true costs of the individual research projects. Hence, the funds from the COE were leveraged with funds from industry and other government agencies. In this way, we feel that all parties benefitted greatly from the collaborative spirit and interactive aspects of the COE. The portion of the support from NASA was particularly important in helping members of the COE to set aside the time to publish papers and communicate advances in our understanding of human performance in NASA-related missions.

Wandell, Brian A.↗