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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 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Water impact loads

Computer program to generate time history of load factor and pressure on conical body of revolution during impact with water is discussed. Program calculates depth of penetration, velocity, force, load factor, maximum pressure at water line, and average pressure. Program is written in FORTRAN 4 Level H for IBM 360/85/195 Release 20.1 computer.

Sanders, D. H.↗
NASA NTRS1971

Flight-determined aerodynamic stability and control derivatives of the M2-F2 lifting body vehicle at subsonic speeds

Aerodynamic derivatives were obtained for the M2-F2 lifting body flight vehicle in the subsonic flight region between Mach numbers of 0.41 and 0.64 and altitudes of 7000 feet to 45,000 feet. The derivatives were determined by a flight time history curve-fitting process utilizing a hybrid computer. The flight-determined derivatives are compared with wind-tunnel and predicted values. Modal-response characteristics, calculated from the flight derivatives, are presented.

Kempel, R. W.↗
NASA NTRS1971

Deployment loads data from a free-flight investigation of all flexible parawings having 371.612 sq meters (4000 sq feet) of wing area

A free-flight test program to determine the deployment characteristics of all-flexible parawings was conducted. Both single-keel and twin-keel parawings having a wing area of 4000 square feet with a five-stage reefing system were tested by use of a bomb-type instrumented test vehicle. Several twin-keel-parawing tests were also made by using an instrumented controllable sled-type test vehicle. The systems were launched from either a C-130 or a C-119 carrier airplane, and a programer parachute was used to bring the test vehicle to a proper dynamic pressure and near-vertical flight path prior to deployment of the parawing system. The free-flight deployment loads data are presented in the form of time histories of individual suspension-line loads and total loads.

Croom, D. R.↗
NASA NTRS1971

IMP series report/bibliography

The main characteristics of the IMP spacecraft and experiments are considered and the scientific knowledge gained is presented in the form of abstracts of scientific papers using IMP data. Spacecraft characteristics, including temporal and spatial coverages, are presented followed by an annotated bibliography. Experiments conducted on all IMP's (including prelaunch IMP's H and J) are described. Figures are presented showing the time histories, through the end of 1970, of magnetic field, plasma, and energetic particle experiments.

King, J. H.↗
NASA NTRS1972

Longitudinal stability and control derivatives of a jet fighter airplane extracted from flight test data by utilizing maximum likelihood estimation

A method of parameter extraction for stability and control derivatives of aircraft from flight test data, implementing maximum likelihood estimation, was developed and successfully applied to actual longitudinal flight test data from a modern sophisticated jet fighter. The results of this application establish the merits of the estimation technique and its computer implementation(allowing full analyst interaction with the program) as well as provide data for the validation of a portion of the differential maneuvering simulator (DMS). The results are presented for all flight test runs in tabular form and as time history comparisons between the estimated states and the actual flight test data. Comparisons between extracted and manufacturer's values for five major derivatives are presented and reveal good agreement for these principal derivatives with one exception. This particular derivative is extensively investigated by utilizing the interactive capabilities of the computer program. The results of this investigation verify the numbers extracted by maximum likelihood estimation.

Steinmetz, G. G.↗
NASA NTRS1972

Aerodynamic parameters of the Navion airplane extracted from flight

An iterative method, which is characterized as a maximum-likelihood minimum-variance technique, was used to extract the aerodynamic parameters of a Navion airplane from flight data. The purposes were to compare the results with parameters obtained from wind-tunnel tests and with results obtained by analog matching the same data, and to develop techniques for application of the parameter extraction program. Results from the study showed that the parameter-extraction program can produce aerodynamic parameters which will permit close estimation of the aircraft time histories used in the extraction process. The program determined an estimate of the standard deviations of the states and parameters. These estimates were used to indicate how well the calculated states fit the flight data and the confidence in the values of the estimated parameters. The study also showed that the values of the parameters were affected by the data and mathematical model used during the extraction process. Because of the lack of confidence in the parameters extracted by use of some of the sets of data, several parameters were estimated by other methods. By using a combination of methods, a set of parameters which gave a fit to the data was obtained.

Suit, W. T.↗
NASA NTRS1972

Lunar ephemeris and selenographic coordinates of the earth and sun for 1971 and 1972

Ephemeris data are presented for each month of 1971 and 1972 to provide a time history of lunar coordinates and related geometric information. A NASA Manned Spacecraft Center modification of the Jet Propulsion Laboratory ephemeris tape was used to calculate and plot coordinates of the earth, moon, and sun. The ephemeris is referenced to the mean vernal equinox at the nearest beginning of a Besselian year. Therefore, the reference equinox changes from one year to the next between 30 June and 1 July. The apparent discontinuity in the data is not noticeable in the graphical presentation, but can be observed in the digital output. The mean equator of epoch is used in all cases. The computer program used to compute and plot the ephemeris data is described.

Hartung, A. D.↗
NASA NTRS1972

Lunar ephemeris and selenographic coordinates of the earth and sun for 1973 and 1974

Ephemeris data are presented for each month of 1973 and 1974 to provide a time history of lunar coordinates and related geometric information. A NASA Manned Spacecraft Center modification of the Jet Propulsion Laboratory ephemeris tape was used to calculate and plot coordinates of the earth, moon, and sun. The ephemeris is referenced to the mean vernal equinox at the nearest beginning of a Besselian year. Therefore, the reference equinox changes from one year to the next between 30 June and 1 July. The apparent discontinuity in the data is not noticeable in the graphical presentation, but can be observed in the digital output. The mean equator of epoch is used in all cases. The computer program used to compute and plot the ephemeris data is described.

Hartung, A. D.↗
NASA NTRS1972

Radiative transfer effects behind reflected shock waves

Theoretical studies are reported which were largely centered on the nonequilibrium coupling of collisional, ionization, and radiative transfer processes behind reflected shock waves in nitrogen. Experimental studies included broad-band photomultiplier radiative intensity measurements, luminosity photographs of the reflected shock wave front, end-wall heat transfer measurements, and reflected shock velocity time-history measurements. The results of these activities are summarized, and comparisons between the theoretical and experimental results are discussed.

Nerem, R. M.↗
NASA NTRS1972

Lunar ephemeris selenographic coordinates of the earth and sun for 1975 and 1976

Ephemeris data are presented for 1975 and 1976 to provide a time history of lunar coordinates and related geometric information. A Manned Spacecraft Center modification of the Jet Propulsion Laboratory ephemeris tape was used to calculate and plot coordinates of the earth, moon, and sun. The ephemeris is referenced to the mean vernal equinox at the nearest beginning of a Besselian year. Therefore the reference equinox changes from one year to the next between 30 June and 1 July. The apparent discontinuity in the data is not noticeable in the graphical presentation, but can be observed in the digital output. The mean equator of epoch is used in all cases.

Hartung, A. D.↗
NASA NTRS1972

Experimental evaluation of a TF30-P-3 turbofan engine in an altitude facility: Afterburner performance and engine-afterburner operating limits

For distortion free steady state operation at the maximum (full afterburning) throttle position, the afterburner combustion efficiency decreased from 0.91 to 0.68 as engine inlet Reynolds number index was reduced from 0.80 to 0.25. Engine afterburner operational limits were obtained for transient and fixed throttle operation over a range of engine inlet distortions. At limiting conditions, time histories of pressures in the fan compressor during throttle transients between military and maximum showed the development of rotating stall in the fan hub which quickly propagated and produced complete stall in the high pressure compressor.

Mcaulay, J. E.↗
NASA NTRS1972

Anisotropies in the interplanetary intensity of solar protons E sub p 0.3 MeV

From the data on solar protons with energy 0.3 MeV obtained by Explorer 35 since July 1967, ten events were selected for the study of intensity vs time and of angular distributions of intensity in interplanetary space near the earth. The bases of selection were that the events be of adequate intensity for statistically satisfactory study and that they be attributable to a single solar flare so that their time histories were not complicated by overlapping emissions of particles. The principal findings for these events are presented.

Innanen, W. G.↗