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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 NTRS1978

Work Capability and physiological effects predictive studies. 4: In He-O2 excursions to pressures of 400- 800- 1200- and 1600 feet of sea water

Experiments which exposed men in chambers, breathing helium with oxygen, to progressive increases of pressure equivalent to 400-800-1200-1600 feet of sea water (fsw) were conducted. Rates of compression and exposure to stable high pressure. Goals included: 1) determination of the specific character and time course of onset of physiological and performance decrements during the intentionally rapid compressions, and determination of rates of adaptation on reaching stable elevated pressure; 2) investigation of accelerated methods for decompression in deep saturation excursion diving; and 3) determination of competence in practical work performed in water at pressures equivalent to the extreme diving depths of 1200 and 1600 fsw.

Lambertsen, C. J.↗
NASA NTRS1983

The ARGOS system used for tracking gray whales

The development of satellite whale tags used to track gray whales in the eastern north Pacific Ocean is summarized. Two gray whales were radio-tagged in San Ignacio Lagoon (Mexico) and tracked on their northbound migration. One of the transmitters was modified to record and relay depth-of-dive information at 15 sec intervals throughout the course of the dive. Technical elements of data acquisition and analysis are outlined. The major biological findings are discussed.

Mate, B. R.↗
NASA NTRS1986

Low-Gravity Alloy Studies on Aircraft

Controlled solidification continued through many dives. Since each dive gives 20 to 30 seconds in which gravity is 0.001 to 0.1 its normal value, and aircraft may make about ten low-gravity maneuvers in mission, technique allows substantial time to conduct a low-gravity experiment. In directional solidification, liquid/solid interface advanced slowly through rod of sample alloy. Solidification continues during several aircraft maneuvers. Known solidification rate of sample correlated with accelerometer data to find gravity value during solidification for any point in sample. Thermal gradient and solidification rate controlled independently.

Curreri, P. A.↗
NASA NTRS1986

Sensing Horizontal Heading in Aircraft Maneuvers

Modified gyroscopic system indicates geographic heading even in nearly vertical flight. Gyroscopes and gimbals of system assume this configuration when aircraft has pitched into vertical dive. Outer roll gimbal fixed with respect to aircraft frame in this orientation. Now, azimuth signal in modified system indicates what aircraft heading would be if it were to resume level flight from climb or dive.

Cowdin, K. T.↗
NASA NTRS1990

Applications of low temperature CO-oxidation catalysts to breathable gases

Modifications of tin oxide/precious metal catalysts described for use in CO2 lasers have also been developed for use in other applications; namely, as low temperature CO oxidation components in fire escape hoods/masks for mines, aircrafts, hotels, and offices and in sealed environments, such as hyperbaric chambers and submarines. Tin oxide/precious metal catalysts have been prepared on a variety of high surface area cloth substrates for application in fire escape hoods. These show high and stable CO oxidation capability (10 to the 4th power ppm CO reduced to 10 to the 1st power ppm CO) at GHSV of 37,000 h(-1) with water saturated inlet gas at body heat (37 C) and below. Water vapor plays an important role in the surface state/performance of tin oxide catalyst. Water-resistant formulations have been produced by the introduction of transition metal promoters. Tin oxide/precious metal catalysts have also been developed for CO oxidation in the North Sea diving environment. These are currently in use in a variety of hyperbaric chambers and diving vehicles. Ambient temperature operation and resistance to atmospheric water vapor have been demonstrated, and as a result, they offer a viable alternative to hopcalite or heated catalyst systems. A new range of non-tin oxide based low temperature CO oxidation catalysts is described. They are based on reducible metal oxides promoted with previous metals. Preliminary data on selected materials in the form of both cloth artifacts and shaped pellets are presented. They are expected to be applicable both to the breathable gas application area and to CO2 lasers.

Noordally, Ehsan↗
NASA NTRS1993

Airborne Laboratory Apparatus Draws Glass Fibers

Glass-fiber-drawing apparatus designed for studies of effect of gravitation on drawing process. Clear plastic housing surrounds fiber-drawing equipment and some of associated electronic instrumentation. External rack holds video monitor, personal computer, keyboard, videotape recorder, and power switch panel. Mounted in research aircraft, apparatus makes continuous video recordings of formation of fiber at effective gravitational accelerations ranging from 0.001 to 2 times normal Earth gravitational acceleration as aircraft dives, then pulls out of dives. Also records pertinent process data on video image.

Tucker, Dennis S.↗
NASA NTRS1992

Near-optimal energy transitions for energy-state trajectories of hypersonic aircraft

A problem of the instantaneous energy transition that occurs in energy-state approximation is considered. The transitions are modeled as a sequence of two load-factor bounded paths (either climb-dive or dive-climb). The boundary-layer equations associated with the energy-state dynamic model are analyzed to determine the precise location of the transition.

Ardema, M. D.↗
NASA NTRS1941

Velocity gained and altitude lost in recoveries from inclined flight paths

A series of charts is given showing the variation of the velocity gained and the altitude lost in dive pullouts with the initial indicated air speed and the dive angle. The effects of the maximum load factor, the drag parameter K, the initial altitude, and the type of recovery on the velocity gained and the altitude lost are also considered. The results were obtained from a step-by-step solution of the equations of motion in which mean values of the air density and the airplane drag coefficient were used. The load-factor variation with time is arbitrarily specified in various ways to simulate pull-out procedures, some of which might be encountered in flight.

Pearson, H A↗
NASA NTRS1943

The problem of longitudinal stability and control at high speeds

In high-speed dives many airplanes exhibit a dangerous tendency to continue diving in spite of the application of large control forces. Wind-tunnel tests have confirmed that these difficulties are not peculiar to any particular configuration, so that the problem is of interest to all designers of high-speed airplanes. The purpose of this report is to acquaint designers with the cause of difficulties and with the means now known for their alleviation.

Hood, Manley J↗
NASA NTRS1995

TRISTAR 1: Evaluation methods for testing head-up display (HUD) flight symbology

The first in a series of piloted head-up display (HUD) flight symbology studies (TRISTAR) measuring pilot task performance was conducted at the NASA Ames Research Center by the Tri-Service Flight Symbology Working Group (FSWG). Sponsored by the U.S. Army Aeroflightdynamics Directorate, this study served as a focal point for the FSWG to examine HUD test methodology and flight symbology presentations. HUD climb-dive marker dynamics and climb-dive ladder presentations were examined as pilots performed air-to-air (A/A), air-to-ground (A/G), instrument landing system (ILS), and unusual attitude (UA) recover tasks. Symbolic presentations resembled pitch ladder variations used by the U.S. Air Force (USAF), U.S. Navy (USN), and Royal Air Force (RAF). The study was initiated by the FSWG to address HUD flight symbology deficiencies, standardization, issue identification, and test methodologies. It provided the mechanism by which the USAF, USN, RAF, and USA could integrate organizational ideas and reduce differences for comparisons. Specifically it examined flight symbology issues collectively identified by each organization and the use of objective and subjective text methodology and flight tasking proposed by the FSWG.

Newman, R. L.↗
NASA NTRS1960

Longitudinal Aerodynamic Characteristics of a Four-Propeller Deflected Slipstream VTOL Model Including the Effects of Ground Proximity

Results are presented of a wind-tunnel investigation of the longitudinal stability, control, and performance characteristics of a model of a four-propeller deflected-slipstream VTOL airplane in the transition speed range. These results indicate that steady level-flight transition and descending flight-path angles up to 7 or 8 deg. out of the region of ground effect can be accomplished without wing stall being encountered. In general, the pitching moments out of ground proximity can be adequately trimmed by programming the stabilizer incidence to increase with increasing flap deflection, except for a relatively large diving moment in the hovering condition. The deflection of the slipstream onto the horizontal tail in proximity of the ground substantially increases the diving moment in hovering, unless the tail is set at a large nosedown incidence.

Kuhn, Richard E.↗
NASA NTRS1960

Low-Speed Investigation of a Full-Span Internal-Flow Jet-Augmented Flap on a High-Wing Model with a 35 deg Swept Wing of Aspect Ratio 7.0

An investigation of a full-span 17-percent-chord internal-flow jet-augmented flap on an aspect-ratio-7.0 wing with 35 deg of sweepback has been made in the Langley 300-MPH 7- by 10-foot tunnel. Blowing over the conventional elevator and blowing down from a nose jet were investigated as a means of trimming the large diving moments at the high momentum and high lift coefficients. The results of the investigation showed that the model with the horizontal tail 0.928 mean aerodynamic chord above the wing-chord plane was stable to the maximum lift coefficient. The large diving-moment coefficients could be trimmed either with a downward blowing nose jet or by blowing over the elevator. Neither the downward blowing nose jet nor blowing over the elevator greatly affected the static longitudinal stability of the model. Trimmed lift coefficients up to 8.8 with blowing over the elevator and up to 11.4 with blowing down at the nose were obtained when the flap was deflected 70 deg and the total momentum coefficients were 3.26 and 4.69.

Turner, Thomas R.↗
NASA NTRS1947

Ditching Tests with a 1/16-Size Model of the Navy XP2V-1 Airplane at the Langley Tank No. 2 Monorail

Tests were made with a 1/16 size dynamically similar model of the Navy XP2V-1 airplane to study its performance when ditched. The model was ditched in calm water at the Langley tank no. 2 monorail. Various landing attitudes, speeds, and conditions of damage were simulated. The performance of the node1 was determined and recorded from visual observations, by recording time histories of the longitudinal decelerations, and by taking motion pictures of the ditchings From the results of the tests with the model the following conclusions were drawn: 1. The airplane should be ditched at the normal landing attitude. The flaps should be fully extended to obtain the lowest possible landing speed; 2. Extensive damage will occur in a ditching and the airplane probably will dive violently after a run of about 2 fuselage lengths. Maximum longitudinal decelerations up to about 4g will be encountered; and 3. If a trapezoidal hydroflap 4 feet by 2 feet by 1 foot is attached to the airplane at station 192.4, diving will be prevented and the airplane will probably porpoise in a run of about 4 fuselage lengths with a maximum longitudinal deceleration of less than 3.5g.

Fisher, Lloyd J.↗
NASA NTRS1948

Free-Spinning-Tunnel Tests of a 1/24-Scale Model of the North American XP-86 Airplane

A spin investigation has been conducted in the Langley 20-foot free-spinning tunnel on a 1/24-scale model of the North American XP-86 airplane. The effects of control settings and movements upon the erect and inverted spin and recovery characteristics of the model were determined for the design gross weight loading. The long-range loading was also investigated and the effects of extending slats and dive flaps were determined. In addition, the investigation included the determination of the size of spin-recovery parachute required for emergency recovery from demonstration spins, the rudder force required to move the rudder for recovery, and the best method for the pilot to escape if it should become necessary to do so during a spin. The results of the investigation indicated that the XP-86 airplane will probably recover satisfactorily from erect and inverted spins for all possible loadings. It was found that fully extending both slats would be beneficial but that extending the dive brakes would cause unsatisfactory recoveries. It was determined that a 10.0-foot-diameter tail parachute with a drag coefficient of 0.7 and with a towline 30.0 feet long attached below the jet exit or a 6.0-foot-diameter wingtip parachute opened on the outer wing tip with a towline 6.0 feet long would insure recoveries from any spins obtainable. The rudder-pedal force necessary to move the rudder for satisfactory recovery was found to be within the physical capabilities of the pilot.

Berman, Theodore↗
NASA NTRS2004

Gender and Decompression Sickness: A Critical Review and Analysis

The author addressed the following questions: are women at greater risk of decompression sickness and venous gas emboli at certain times in their reproductive cycle, is risk modified by the use of birth control pills (BCP), and is there a difference in overall risk between men and women under the same decompression dose? The summary considers information from the few abstracts and reports that were available. Except for the observation of more Type II DCS in women, particularly in women who fly after diving, there was no compelling evidence of a difference in DCS risk between men and women SCUBA divers. Many women that presented with DCS symptoms seemed to be in or near menses, with statistically fewer cases reported as time increased from menses. There was no compelling evidence that the use of BCP in SCUBA divers increases the risk of DCS. There were insufficient data about VGE from SCUBA diving to make any conclusion about the incidence of VGE and gender. In contrast, there were ample data about VGE from research in altitude chambers. Women produced less VGE and less Grade IV VGE compared to men under the same decompression dose, certainly when resting oxygen prebreathe (PB) was performed prior to ascent to altitude. Dual-cycle ergometry exercise during PB tends to reduce the differences in VGE between men and women. There was no compelling evidence that the risk of altitude DCS was different between men and women. However, a large number of DCS cases were associated with menses, and the use of BCP did seem to put women at a slightly greater risk than those that did not use BCP. There were substantial observations that women comprised a larger number of difficult cases that required complicated medical management.

Source record↗
NASA NTRS1954

Additional Results on the Static Longitudinal and Lateral Stability Characteristics of a 0.05-Scale Model of the Convair F2Y-1 Airplane at High Subsonic Speeds

Additional results on the static longitudinal and lateral stability characteristics of a 0.05-scale model of the Convair F2Y-1 water-based fighter airplane were obtained in the Langley high-speed 7- by 10-foot tunnel over a Mach number range of 0.50 to 0.92. The maximum angle-of-attack range (obtained at the lower Mach numbers) was from -2 degrees to 25 degrees. The sideslip-angle range investigated was from -4 degrees to 12 degrees. The investigation included effects of various arrangements of wing fences, leading-edge chord-extensions, and leading-edge notches. Various fuselage fences, spoilers, and a dive brake also were investigated. From overall considerations of lift, drag, and pitching moments, it appears that there were two modifications somewhat superior to any of the others investigated: One was a configuration that employed a full-chord fence and a partial-chord fence located at 0.63 semispan and 0.55 semispan, respectively. The second was a leading-edge chord-extension that extended from 0.68 semispan to 0.85 semispan in combination with a leading-edge notch located at 0.68 semispan. With plus or minus 10 degrees aileron, the estimated wing-tip helix angle was reduced from 0.125 at a Mach number of 0.50 to 0.088 at a Mach number of 0.92, with corresponding rates of roll of 4.0 and 5.2 radians per second. The upper aft fuselage dive brake, when deflected 30 degrees and 60 degrees, reduced the rudder effectiveness about 10 to 20 percent and about 35 to 50 percent, respectively.

Spreeman, Kenneth P.↗
NASA NTRS1949

Ditching Investigation of a 1/18-Scale Model of the North American B-45 Airplane

An investigation of a 1/18-scale dynamically similar model of the North American B-45 airplane was made to observe the ditching behavior and determine the proper landing technique to be used in an emergency water landing. Various conditions of damage were simulated to determine the behavior which probably would occur in a full-scale ditching. The behavior of the model was determined from high-speed motion-picture records, time-history acceleration records, and visual observations. It was concluded that the airplane should be ditched at the maximum nose-high attitude with the landing flaps full down for minimum landing speed. During the ditching, the nose-wheel and bomb-bay doors probably will be torn away and the rear of the fuselage flooded. A violent dive will very likely occur. Longitudinal decelerations of approximately 5g and vertical accelerations of approximately -6g (including gravity) will be experienced near the pilots' compartment. Ditching braces installed in the bomb bay will tend to improve the behavior slightly but will be torn away along with the bomb-bay doors. A hydroflap installed ahead of the nose-wheel doors will eliminate the dive and failure of the nose-wheel doors, and substantially reduce the motions and accelerations.

Fisher, Lloyd J.↗
NASA NTRS2011

Kennedy Space Center ITC-1 Internship Overview

As an intern for Priscilla Elfrey in the ITC-1 department, I was involved in many activities that have helped me to develop many new skills. I supported four different projects during my internship, which included the Center for Life Cycle Design (CfLCD), SISO Space Interoperability Smackdown, RTI Teacher Mentor Program, and the Discrete Event Simulation Integrated Visualization Environment Team (DIVE). I provided the CfLCD with web based research on cyber security initiatives involving simulation, education for young children, cloud computing, Otronicon, and Science, Technology, Engineering, and Mathematics (STEM) education initiatives. I also attended STEM meetings regarding simulation courses, and educational course enhancements. To further improve the SISO Simulation event, I provided observation feedback to the technical advisory board. I also helped to set up a chat federation for HLA. The third project involved the RTI Teacher Mentor program, which I helped to organize. Last, but not least, I worked with the DIVE team to develop new software to help visualize discrete event simulations. All of these projects have provided experience on an interdisciplinary level ranging from speech and communication to solving complex problems using math and science.

Ni, Marcus↗