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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 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

Ascent performance and abort analysis for a Future Space Transportation System

The Future Space Transportation System (FSTS) study was conducted by the NASA Langley Research Center to identify the technology requirements for concepts that will replace the Space Shuttle in the post 2000 time frame. The configuration chosen for the study is a two-stage, fully reusable, vertical liftoff, and horizontal landing system with a 150,000 lb. payload capability. The two stages are burned in parallel with the booster providing all the propellant until staging, which results in a large lateral c.g. movement. Nominally, the booster stages at Mach 3 and glides back to the launch site. Because of the large lateral c.g. travel, a scheme to trim the vehicle until staging occurred was developed that used both gimballing and throttling of the engines. Preliminary booster aerodynamics were determined, and the booster glideback trajectory was analyzed with and without winds. Finally, a preliminary abort analysis was conducted for each stage.

Naftel, J. C.↗
NASA NTRS2010

Meeting Air Transportation Demand in 2025 by Using Larger Aircraft and Alternative Routing to Complement NextGen Operational Improvements

A study was performed that investigates the use of larger aircraft and alternative routing to complement the capacity benefits expected from the Next Generation Air Transportation System (NextGen) in 2025. National Airspace System (NAS) delays for the 2025 demand projected by the Transportation Systems Analysis Models (TSAM) were assessed using NASA s Airspace Concept Evaluation System (ACES). The shift in demand from commercial airline to automobile and from one airline route to another was investigated by adding the route delays determined from the ACES simulation to the travel times used in the TSAM and re-generating new flight scenarios. The ACES simulation results from this study determined that NextGen Operational Improvements alone do not provide sufficient airport capacity to meet the projected demand for passenger air travel in 2025 without significant system delays. Using larger aircraft with more seats on high-demand routes and introducing new direct routes, where demand warrants, significantly reduces delays, complementing NextGen improvements. Another significant finding of this study is that the adaptive behavior of passengers to avoid congested airline-routes is an important factor when projecting demand for transportation systems. Passengers will choose an alternative mode of transportation or alternative airline routes to avoid congested routes, thereby reducing delays to acceptable levels for the 2025 scenario; the penalty being that alternative routes and the option to drive increases overall trip time by 0.4% and may be less convenient than the first-choice route.

Smith, Jeremy C.↗
NASA NTRS1968

Analysis of flutter in tape transport systems

Effect of flutter on digital data is recorded by magnetic tape recorders used with instrumentation systems. Major effect for both FM and direct recording techniques is shown to be a perturbation of the signal time base.

Davis, R. C.↗
NASA NTRS1973

Land resources survey for the state of Michigan

The usefulness of ERTS-1 satellite imagery as an information source for a statewide inventory of Michigan's land resources is documented. The project is currently relying on photointerpretation of MSS photography and computed processed results. The first task completed was a 1:500,000 scale land use map of the state in four classes: urban, forest, water, and agriculture and other. This map was constructed from existing (pre-ERTS-1) information sources including federal, state and county maps, and aerial photography. An ERTS color IR photomosaic for the entire state will also be constructed at a scale of 1:250,000. The Institute is currently working on tape processed data that will include both recognition data as well as a UTM coordinate addressing capability so that the final tape can be inputed directly into computerized land use and transportation corridor analysis models.

Sellman, B.↗
NASA NTRS1972

The ATA-67 Formula for Direct Operating Cost

The ATA formulas for direct operating cost were developed for the purpose of comparing different aircraft, existing or not, on the same route or the same aircraft on different routes. Such characteristics of the airline as crew pay, maintenance procedures, and depreciation schedules are kept constant. In air transportation systems analysis the 1967 ATA formula is usually used with appropriate exceptions or modifications, such as: different maintenance labor rate, total maintenance multiplied by a factor, maintenance burden deleted, different depreciation schedule, or different spares percentages.

Faulkner, H. B.↗
NASA NTRS1973

Analysis of a model for transport of charged particles in a random magnetic field

A model for the transport of charged particles in a random magnetic field is a Volterra integrodifferential equation with a long-range kernel. The integrodifferential equation is solved numerically with the method of Bellman, Kalaba, and Lockett (1966). The results are shown to be in excellent agreement with analytical asymptotic results.-

Hanson, F. B.↗
NASA NTRS1976

Cost/benefit tradeoffs for reducing the energy consumption of the commercial air transportation system. Volume 1: Technical analysis

The effectiveness and associated costs of operational and technical options for reduced fuel consumption by Douglas aircraft in the domestic airline fleet are assessed. Areas explored include alternative procedures for airline and flight operations, advanced and state of the art technology, modification and derivative configurations, new near-term aircraft, turboprop configuration studies, and optimum aircraft geometry. Data for each aircraft studied is presented in tables and graphs.

Kraus, E. F.↗
NASA NTRS1979

Solar power satellite system definition study. Volume 2, phase 1: Systems analyses tradeoffs.

A systems definition study of the solar power satellite system is presented. The satellite solar energy conversion and microwave power transmission systems are discussed. Space construction and support systems are examined including a series construction and equipment characteristics analysis. Space transportation for the satellite and the ground receiving station are assessed.

Source record↗
NASA NTRS1980

Computer-aided analysis of nonlinear problems in transport phenomena

The paper describes algorithms for equilibrium and steady-state problems with coefficients in the expansions derived by the Galerkin weighted residual method and calculated from the resulting sets of nonlinear algebraic equations by the Newton-Raphson method. Initial approximations are obtained from nearby solutions by continuation techniques as parameters are varied. The Newton-Raphson technique is preferred because the Jacobian of the solution is useful for continuation, for analyzing the stability of solutions, for detecting bifurcation of solution families, and for computing asymptotic estimates of the effects on any solution of small changes in parameters, boundary conditions, and boundary shape.

Brown, R. A.↗
NASA NTRS1983

An analysis of propulsion options for transport of lunar materials to earth orbit

This paper describes the results of analyses of space-based transportation systems for the transport of extraterrestrial materials from their point of origin on the lunar surface to final delivery point in earth orbit and transport of equipment and supplies for extraterrestrial processing to the operational site. The emphasis has been on the use of near-term (pre-year 2000) propulsion systems, such as advanced chemical (H2, O2) and nuclear-electric systems. More exotic systems (mass drivers, nuclear-thermal rockets, etc.) were also considered to evaluate the potential to be gained by use of post-year 2000 technologies. Finally, the effects of using extraterrestrial propellants (e.g., H2 from lunar polar water-ice for chemical systems) were compared to those of propulsion systems deriving all or part of their propellants from the earth.

Frisbee, R. H.↗
NASA NTRS1989

High accuracy thermal conductivity measurements near the lambda transition of helium with very high temperature resolution

Over the past few years extensive thermal conductivity measurements near the lambda point of helium were made. The original goal of measuring the thermal conductivity with a resolution of t = T/T sub lambda -1 of 3 x 10(-8) was reached, but with somewhat less accuracy than was hoped. Subtle effects in the apparatus near the transition were observed which reduced the ability to interpret the results. Nevertheless, for resolution of t is greater than or equal to 10(-7) reliable data was obtained, extending previous measurements by more than an order of magnitude. Deviations from theoretical predictions were observed for t is less than or equal to 3 x 10(-6) leading to the question of the validity of the present renormalization group analysis of transport properties, at least for the case of helium. This anomaly led to closer examination of the boundary effects in the measurements. During the experiments a totally unexpected effect in the very dilute He-3 - He-4 mixtures was observed which led to the explanation of the anomalous results. The concentration dependence of the thermal conductivity near T sub lambda in the superfluid phase was found to deviate strongly from the predictions. The results gave an independent verification of this behavior and caused reanalysis of the Khalatnikov theory of hydrodynamics of the mixtures. An alternative solution was found which is in better agreement with the experiment.

Fairbank, William M.↗
NASA NTRS1991

Estimate of heavy rain performance effect

The aerodynamic effect of heavy rain on airplane performance is presented in the form of view-graphs. The following subject areas are covered: review of heavy rain airfoil tests; development of heavy rain aerodynamic model for a twin-jet transport; performance analysis with heavy rain effects; numeric simulation of wet microburst encounter; and summary of results and future needs.

Vicroy, Dan D.↗
NASA NTRS1989

An interim reference model for the variability of the middle atmosphere H2O vapor distribution

Water vapor is an important minor constituent in the studies of the middle atmosphere for a variety of reasons, including its role as a source for active HO(y) chemicals and its use in analysis of transport processes. A number of in situ and remote techniques were employed in the determination of water vapor distributions. Two of the more complete data sets were used to develop an interim reference profile. First, there are the seven months of Nimbus 7 limb infrared monitor of the stratosphere (LIMS) data obtained during Nov. 1978 to May 1979 over the range 64S to 84N latitude and from about 100 to 1 mb in the mid-mesosphere at several fixed Northern Hemisphere mid-latitude sites. These two data sets were combined to give a mid-lattitude, interim reference water vapor profile for the entire vertical range of the middle atmosphere and with accuracies of better than 25 percent. The daily variability of stratospheric water vapor profiles about the monthly mean was also established from these data sets for selected months. Information is also provided on the longitudinal variability of LIMS water vapor profiles about the daily, weekly, and monthly zonal means. Generally, the interim reference water vapor profile and its variability are consistent with prevailing ideas about chemistry and transport.

Remsberg, E. E.↗
NASA NTRS1991

The seasonal circulation of the upper ocean in the Bay of Bengal

The present analysis of results generated by a multilayer, adiabatic, monthly mean wind-driven numerical model of the upper Indian Ocean indicates that its simulated northeastern currents are in general agreement with observations and interpretations. Attention is given to the large anticyclonic flow during Northern Hemisphere winter. The model's layer-thickness reveals the propagation of Kelvin waves along the coast, travelling the entire perimeter of the Andaman Sea and Bay of Bengal; this wave excites westward-propagating Rossby waves into the bay's interior. A time-series analysis of transport calculations yields peaks in the 20-30 day and 50-60 day ranges which are unlikely to have been directly forced by the applied stress.

Potemra, James T.↗
NASA NTRS1992

Renormalization group analysis of the Reynolds stress transport equation

The pressure velocity correlation and return to isotropy term in the Reynolds stress transport equation are analyzed using the Yakhot-Orszag renormalization group. The perturbation series for the relevant correlations, evaluated to lowest order in the epsilon-expansion of the Yakhot-Orszag theory, are infinite series in tensor product powers of the mean velocity gradient and its transpose. Formal lowest order Pade approximations to the sums of these series produce a fast pressure strain model of the form proposed by Launder, Reece, and Rodi, and a return to isotropy model of the form proposed by Rotta. In both cases, the model constant are computed theoretically. The predicted Reynolds stress ratios in simple shear flows are evaluated and compared with experimental data. The possibility is discussed of driving higher order nonlinear models by approximating the sums more accurately.

Rubinstein, R.↗