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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 649 records · Page 36
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

High angle canard missile test in the Ames 11-foot transonic wind tunnel

Four blunted ogive-cylinder missile models with a length-to-diameter ratio of 10.4 were tested at transonic speeds and large angles of attack. The configurations are: body, body with tail panels, body with canards, and body with canards and tails. Forces and moments from the entire model and each of the eight fins were measured over the pitch range of 20 deg to 50 deg and 0 deg to 45 deg roll. Canard deflection angles between 0 deg and 15 deg were tested. Exploratory vapor screen flow visualization testing was also performed. Sample force and moment data are reported along with observations from the vapor screen tests.

Schwind, R. G.↗
NASA NTRS1978

Trajectory module of the NASA Ames Research Center aircraft synthesis program ACSYNT

A program was developed to calculate trajectories for both military and commercial aircraft for use in the aircraft synthesis program, ACSYNT. The function of the trajectory module was to calculate the changes in the vehicle's flight conditions and weight, as fuel is consumed, during the flying of one or more missions. The trajectory calculations started with a takeoff, followed by up to 12 phases chosen from among the following: climb, cruise, acceleration, combat, loiter, descent, and paths. In addition, a balanced field length was computed. The emphasis was on relatively simple formulations and analytic expressions suitable for rapid computation since a prescribed trajectory had to be calculated many times in the process of converging an aircraft design, or finding an optimum configuration. The trajectory module consists of about 2500 cards and operational on a CDC 7600 computer.

Tauber, M. E.↗
NASA NTRS1978

Ames collaborative study of cosmic ray neutrons - Mid-latitude flights

Three aircraft flights at 12.5 km have yielded data on cosmic-ray neutron-flux densities, neutron dose equivalent rates, and exposure rates for ionizing radiation. The data, collected at 45, 38, and 48 degrees N, indicate: (1) neutron dose equivalent rates of 0.20, 0.14, and 0.22 mrem/hour, (2) exposure rates from the ionizing component of 0.37, 0.31, and 0.41 mR/hour, (3) that the dose equivalent from 3-13-MeV neutrons is 30% of the total for all neutrons, (4) that exposure rates decrease exponentially with decreasing pressure altitude with a 140 g/sq cm attenuation length at 43 degrees N geomagnetic latitude, and (5) that the ionizing component of cosmic ray secondaries is less sensitive to latitude changes than the neutron component.

Hewitt, J. E.↗
NASA NTRS1978

Canard-body-tail missile test at angles of attack to 50 deg in the Ames 11-foot transonic wind tunnel

Blunted ogive cylinder missile models with a length-to-diameter ratio of 10.4 were tested at transonic speeds and large angles of attack in an 11 foot transonic wind tunnel. The configurations are: body, body with tail panels, body with canards, and body with canards and tails. Forces and moments from the entire model and each of the eight fins were measured over the pitch range of 20 deg to 50 deg, and roll angles of 0 deg to 45 deg and canard deflection angles between 0 deg and 15 deg. The Reynolds number ranged from 3.9 x 10 to the 6th power per meter. Large side forces and yawing moments were observed for some of the test cases involving a symmetric geometry.

Allen, C. Q.↗
NASA NTRS1979

Feasibility study of transit photon correlation anemometer for Ames Research Center unitary wind tunnel plan

A laser transit anemometer measured a two-dimensional vector velocity, using the transit time of scattering particles between two focused and parallel laser beams. The objectives were: (1) the determination of the concentration levels and light scattering efficiencies of naturally occurring, submicron particles in the NASA/Ames unitary wind tunnel and (2) the evaluation based on these measured data of a laser transit anemometer with digital correlation processing for nonintrusive velocity measurement in this facility. The evaluation criteria were the speeds at which point velocity measurements could be realized with this technique (as determined from computer simulations) for given accuracy requirements.

Mayo, W. T., Jr.↗
NASA NTRS1979

The NASA-Ames Research Center stratospheric aerosol model. 2. Sensitivity studies and comparison with observatories

Sensitivity tests were performed on a one-dimensional, physical-chemical model of the unperturbed stratospheric aerosols, and model calculations were compared with observations. The tests and comparisons suggest that coagulation controls the particle number mixing ratio, although the number of condensation nuclei at the tropopause and the diffusion coefficient at high altitudes are also important. The sulfur gas source strength and the aerosol residence time are much more important than the supply of condensation nuclei in establishing mass and large particle concentrations. The particle size is also controlled mainly by gas supply and residence time. In situ observations of the aerosols and laboratory measurements of aerosols, parameters that can provide further information about the physics and chemistry of the stratosphere and the aerosols found there are provided.

Toon, O. B.↗
NASA NTRS1979

The NASA-AMES Research Center Stratospheric Aerosol Model. 1. Physical Processes and Computational Analogs

A time-dependent one-dimensional model of the stratospheric sulfate aerosol layer is presented. In constructing the model, a wide range of basic physical and chemical processes are incorporated in order to avoid predetermining or biasing the model predictions. The simulation, which extends from the surface to an altitude of 58 km, includes the troposphere as a source of gases and condensation nuclei and as a sink for aerosol droplets. The size distribution of aerosol particles is resolved into 25 categories with particle radii increasing geometrically from 0.01 to 2.56 microns such that particle volume doubles between categories.

Turco, R. P.↗
NASA NTRS1979

Ames Research Center publications, 1977

This bibliography lists 786 formal NASA publications, journal articles, books, chapters of books, patents, and contractor reports which appeared during 1977 or which were not included in previous annual bibliographies. Citations are arranged by directorate, type of publication, and author. Each NASA report is identified by a technical report and accession number to facilitate ordering. An author index is provided.

Source record↗
NASA NTRS1979

Earth winds, flow quality, and the minimum-protection inlet treatment for the NASA Ames 80- by 120-foot wind tunnel nonreturn circuit

The effect of the external wind on the quality of the flow in the test section was studied. The flow quality achievable with the complex treatment as well as that with the planned minimum treatment system is discussed. A scale model coupled with on site wind measurements demonstrated that the minimum treatment selected can provide adequate testing capabilities in the presence of the prevailing local winds, and that test programs will not be significantly affected by adverse wind effects on the test section flow quality.

Eckert, W. T.↗
NASA NTRS1978

Radiation energy conversion in space; Conference, 3rd, NASA Ames Research Center, Moffett Field, Calif., January 26-28, 1978, Technical Papers

Concepts for space-based conversion of space radiation energy into useful energy for man's needs are developed and supported by studies of costs, material and size requirements, efficiency, and available technology. Besides the more studied solar power satellite system using microwave transmission, a number of alternative space energy concepts are considered. Topics covered include orbiting mirrors for terrestrial energy supply, energy conversion at a lunar polar site, ultralightweight structures for space power, radiatively sustained cesium plasmas for solar electric conversion, solar pumped CW CO2 laser, superelastic laser energy conversion, laser-enhanced dynamics in molecular rate processes, and electron beams in space for energy storage.

Billman, K. W.↗
NASA NTRS1978

Ames interactive molecular model building system - A 3-D computer modelling system applied to the study of the origin of life

The investigation of specific interactions among biological molecules must take into consideration the stereochemistry of the structures. Thus, models of the molecules are essential for describing the spatial organization of potentially interacting groups, and estimations of conformation are required for a description of spatial organization. Both the function of visualizing molecules, and that of estimating conformation through calculations of energy, are part of the molecular modeling system described in the present paper. The potential uses of the system in investigating some aspects of the origin of life rest on the assumption that translation of conformation from genetic elements to catalytic elements would have been required for the development of the first replicating systems subject to the process of biological evolution.

Coeckelenbergh, Y.↗
NASA NTRS1979

Solid Convection in the Terrestrial Planets; Workshop, NASA Ames Research Center, Moffett Field, Calif., December 12, 13, 1977, Review Papers and Contributions

Review papers and specific contributions on the subject of convection in the solid interiors of the terrestrial planets and planetary evolution are presented. Geophysical observations of solid-state convection in the terrestrial planets are reviewed, along with the theory of convection in a layer with a high Prandtl number and numerical approaches to the calculation of convection in planetary interiors. Other papers treat the formation, history and energetics of terrestrial planet cores, the effects of convection on lunar thermal history and the relation between the height of mountains on Venus and the creep properties of Venusian rocks.

Cassen, P.↗
NASA NTRS1980

A summary of joint US-Canadian augmentor wing powered-lift STOL research programs at the Ames Research Center, NASA, 1975-1980

Several different flight research programs carried out by NASA and the Canadian Government using the Augmentor Wing Jet STOL Research Aircraft to investigate the design, operational, and systems requirements for powered-lift STOL aircraft are summarized. Some of these programs considered handling qualities and certification criteria for this class of aircraft, and addressed pilot control techniques, control system design, and improved cockpit displays for the powered-lift STOL approach configuration. Other programs involved exploiting the potential of STOL aircraft for constrained terminal-area approaches within the context of present or future air traffic control environments. Both manual and automatic flight control investigations are discussed, and an extensive bibliography of the flight programs is included.

Hindson, W. S.↗
NASA NTRS1980

Multicyclic control for helicopters - Research in progress at Ames Research Center

The term multicyclic control describes a blade pitch control technique used by helicopter designers to alleviate vibration in rotorcraft. Because rotor-induced vibrations are periodic, a multicyclic system, synchronized to the main rotor's azimuth position, is suitable. Many types of rotors - ranging from the jet-flap and circulation-control rotors to the conventional full-blade feathering rotors - have utilized multicyclic control. Multicyclic control systems may be designed to reduce blade-bending stresses, to reduce rotor-induced vibration, and to improve rotor performance. Rotor types are reviewed, primarily to highlight their differences. The increased use of composites in blade construction is seen to indicate that vibration alleviation will be the prime focus of multicyclic control. Adaptive feedback control systems, which also incorporate gust alleviation, are considered to be the ultimate application of multicyclic control.

Mccloud, J. L., III↗