Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “performance data”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

ERTS-C (Landsat 3) cryogenic heat pipe experiment definition

A flight experiment designed to demonstrate current cryogenic heat pipe technology was defined and evaluated. The experiment package developed is specifically configured for flight aboard an ERTS type spacecraft. Two types of heat pipes were included as part of the experiment package: a transporter heat pipe and a thermal diode heat pipe. Each was tested in various operating modes. Performance data obtained from the experiment are applicable to the design of cryogenic systems for detector cooling, including applications where periodic high cooler temperatures are experienced as a result of cyclic energy inputs.

Brennan, P. J.↗
NASA NTRS1975

Phase 2 study of improved materials for use on Scout rocket motor nozzles

Nozzle material performance data were obtained, and the feasibility was determined of using new materials on the Scout rocket motor nozzles. Stress and heat transfer analyses were conducted to aid in the selection of optimum materials for nozzle tests. A reimpregnated and graphitized throat insert was fabricated along with two nozzles with ablative throats. The dissection and determining of char and erosion of two nozzles fired on X-259 loaded cases are discussed; one of the nozzles used a graphite phenolic ablative throat insert, and the other unit was a standard X-259 nozzle with a reduced area ATJ graphite throat insert.

Stutzman, R. D.↗
NASA NTRS1975

Experimental clean combustor program, phase 1

Full annular versions of advanced combustor designs, sized to fit within the CF6-50 engine, were defined, manufactured, and tested at high pressure conditions. Configurations were screened, and significant reductions in CO, HC, and NOx emissions levels were achieved with two of these advanced combustor design concepts. Emissions and performance data at a typical AST cruise condition were also obtained along with combustor noise data as a part of an addendum to the basic program. The two promising combustor design approaches evolved in these efforts were the Double Annular Combustor and the Radial/Axial Combustor. With versions of these two basic combustor designs, CO and HC emissions levels at or near the target levels were obtained. Although the low target NOx emissions level was not obtained with these two advanced combustor designs, significant reductions were relative to the NOx levels of current technology combustors. Smoke emission levels below the target value were obtained.

Bahr, D. W.↗
NASA NTRS1974

High voltage power Schottky diodes

Calculations of the low frequency rectification efficiency of power Schottky diodes show that silicon Schottky rectifiers have lower losses than silicon p-n junctions for all voltage applications up to approximately 150 volts. These calculations are presented. Large area Schottky diodes have been fabricated which exhibit near ideal reverse leakage at 100 C out to approximately 100 volts and which have current capability of 100 A. Fabrication details and performance data are presented.

Cordes, L. F.↗
NASA NTRS1974

On-orbit performance of the Skylab astronaut maneuvering research vehicle

The present work evaluates the results of flight tests of the Astronaut Maneuvering Research Vehicle (AMRV) conducted inside the Skylab Orbital Workshop. The vehicle is an autonomous mobility aid which allows the pilot to control his position and orientation in space without the necessity of reacting against the spacecraft. The purpose of the tests was to obtain operation experience and engineering/human performance data in a zero gravity environment, to correlate on-orbit data with simulation data, and to recommend a design configuration for future operational maneuvering units. Four different techniques for controlling AMRV dynamics were tested: hand-held maneuvering unit, direct, rate gyro, and control moment gyro operating modes.

Murtagh, T. B.↗
NASA NTRS1975

Parametric evaluation of a dual-layer dynamic hyperfiltration membrane for recovery of spacecraft wash water at elevated temperature

Performance data consisting of solute rejections and product flux have been measured, as dependent on the operational parameters. These parameters were pressure, 5,000,000 N/sq m (750 psia) to 7,000,000 N/sq m (1040 psia); temperature, 347 K (165 F) to 368 K (200 F); velocity, 1.6 m/s to 10 m/s; and concentration (up to 14x). Tests were carried out on analog wash water. Data taken include rejections of organic materials (TOC), ammonia, urea, and an assortment of ions. The membrane used was a dual-layer, polyacrylic acid over zirconium oxide, deposited in situ on a porcelain ceramic substrate.

Brandon, C. A.↗
NASA NTRS1975

Flight testing air-to-air missiles for flutter

The philosophy of the design of air-to-air missiles and hence of flight testing them for flutter differs from that of manned aircraft. Primary emphasis is put on analytical and laboratory evaluation of missile susceptibility to aeroelastic and aero-servo-elastic instabilities and uses flight testing for confirmation of the absence of such instabilities. Flight testing for flutter is accomplished by using specially instrumented programmed missiles, air or ground launched with a booster to reach the extreme flight conditions of tactical use, or by using guided missiles with telemetered performance data. The instrumentation and testing techniques are discussed along with the success of recent flight tests.

Kutschinski, C. R.↗
NASA NTRS1975

Lay out, test verification and in orbit performance of HELIOS a temperature control system

HELIOS temperature control system is described. The main design features and the impact of interactions between experiment, spacecraft system, and temperature control system requirements on the design are discussed. The major limitations of the thermal design regarding a closer sun approach are given and related to test experience and performance data obtained in orbit. Finally the validity of the test results achieved with prototype and flight spacecraft is evaluated by comparison between test data, orbit temperature predictions and flight data.

Brungs, W.↗
NASA NTRS1975

The 15 cm mercury ion thruster research 1975

Doubly charged ion current measurements in the beam of a SERT II thruster are shown to introduce corrections which bring its calculated thrust into close agreement with that measured during flight testing. A theoretical model of doubly charged ion production and loss in mercury electron bombardment thrusters is discussed and is shown to yield doubly-to-singly charged ion density ratios that agree with experimental measurements obtained on a 15 cm diameter thruster over a range of operating conditions. Single cusp magnetic field thruster operation is discussed and measured ion beam profiles, performance data, doubly charged ion densities, and discharge plasma characteristics are presented for a range of operating conditions and thruster geometries. Variations in the characteristics of this thruster are compared to those observed in the divergent field thruster and the cusped field thruster is shown to yield flatter ion beam profiles at about the same discharge power and propellant utilization operating point. An ion optics test program is described and the measured effects of grid system dimensions on ion beamlet half angle and diameter are examined. The effectiveness of hollow cathode startup using a thermionically emitting filament within the cathode is examined over a range of mercury flow rates and compared to results obtained with a high voltage tickler startup technique. Results of cathode plasma property measurement tests conducted within the cathode are presented.

Wilbur, P. J.↗
NASA NTRS1976

Dual frequency feed system for the CTS communications link characterization experiment

The developing, testing and installation of a dual frequency feed assembly were described. The feed has been designed to receive signals in the frequency range 11.7 to 12.2 GHz and transmit signals in the frequency range 14.12 GHz plus or minus 250 MHz. Complete performance data of the feed alone and installed in the 15 foot antenna is included herein. Drawings and descriptive information of the feed assembly are also given.

Gill, G. J.↗
NASA NTRS1976

Chemical vapor deposition growth

A chemical vapor deposition (CVD) reactor system with a vertical deposition chamber was used for the growth of Si films on glass, glass-ceramic, and polycrystalline ceramic substrates. Silicon vapor was produced by pyrolysis of SiH4 in a H2 or He carrier gas. Preliminary deposition experiments with two of the available glasses were not encouraging. Moderately encouraging results, however, were obtained with fired polycrystalline alumina substrates, which were used for Si deposition at temperatures above 1,000 C. The surfaces of both the substrates and the films were characterized by X-ray diffraction, reflection electron diffraction, scanning electron microscopy optical microscopy, and surface profilometric techniques. Several experiments were conducted to establish baseline performance data for the reactor system, including temperature distributions on the sample pedestal, effects of carrier gas flow rate on temperature and film thickness, and Si film growth rate as a function of temperature.

Ruth, R. P.↗
NASA NTRS1976

An inexpensive economical solar heating system for homes

A low-cost solar home heating system to supplement existing warm-air heating systems is described. The report is written in three parts: (1) a brief background on solar heating, (2) experience with a demonstration system, and (3) information for the homeowner who wishes to construct such a system. Instructions are given for a solar heating installation in which the homeowner supplies all labor necessary to install off-the-shelf components estimated to cost $2,000. These components, which include solar collector, heat exchanger, water pump, storage tank, piping, and controls to make the system completely automatic, are available at local lumber yards, hardware stores, and plumbing supply stores, and are relatively simple to install. Manufacturers and prices of each component used and a rough cost analysis based on these prices are included. This report also gives performance data obtained from a demonstration system which was built and tested at the Langley Research Center.

Allred, J. W.↗
NASA NTRS1976

Continuation of advanced crew procedures development techniques

An operational computer program, the Procedures and Performance Program (PPP) which operates in conjunction with the Phase I Shuttle Procedures Simulator to provide a procedures recording and crew/vehicle performance monitoring capability was developed. A technical synopsis of each task resulting in the development of the Procedures and Performance Program is provided. Conclusions and recommendations for action leading to the improvements in production of crew procedures development and crew training support are included. The PPP provides real-time CRT displays and post-run hardcopy output of procedures, difference procedures, performance data, parametric analysis data, and training script/training status data. During post-run, the program is designed to support evaluation through the reconstruction of displays to any point in time. A permanent record of the simulation exercise can be obtained via hardcopy output of the display data and via transfer to the Generalized Documentation Processor (GDP). Reference procedures data may be transferred from the GDP to the PPP. Interface is provided with the all digital trajectory program, the Space Vehicle Dynamics Simulator (SVDS) to support initial procedures timeline development.

Arbet, J. D.↗
NASA NTRS1976

Coordinated design of coding and modulation systems

Work on partial unit memory codes continued; it was shown that for a given virtual state complexity, the maximum free distance over the class of all convolutional codes is achieved within the class of unit memory codes. The effect of phase-lock loop (PLL) tracking error on coding system performance was studied by using the channel cut-off rate as the measure of quality of a modulation system. Optimum modulation signal sets for a non-white Gaussian channel considered an heuristic selection rule based on a water-filling argument. The use of error correcting codes to perform data compression by the technique of syndrome source coding was researched and a weight-and-error-locations scheme was developed that is closely related to LDSC coding.

Massey, J. L.↗
NASA NTRS1976

A flight investigation of a terminal area navigation and guidance concept for STOL aircraft

A digital avionics system was installed in the CV-340 transport aircraft. Flight tests were made to obtain preliminary performance data in the manual flight director mode using time controlled guidance. These tests provide a basis for selection of terminal area guidance, navigation, and control system concepts for short haul aircraft and for investigating operational procedures.

Smith, D. W.↗
NASA NTRS1976

Development of an inflatable radiator system

Conceptual designs of an inflatable radiator system developed for supplying short duration supplementary cooling of space vehicles are described along with parametric trade studies, materials evaluation/selection studies, thermal and structural analyses, and numerous element tests. Fabrication techniques developed in constructing the engineering models and performance data from the model thermal vacuum tests are included. Application of these data to refining the designs of the flight articles and to constructing a full scale prototype radiator is discussed.

Leach, J. W.↗
NASA NTRS1975

ATS-6 description

Basic design features of Applications Technology Satellite-6 (ATS-6) are discussed, and a variety of experiments carried out with the satellite is described. The 9.1 m reflector is a furlable 48-rib design. The earth viewing module housing most of the electronics is connected to the reflector by an A-frame truss made of graphic fiber reinforced plastic with excellent dimensional stability over a wide temperature range. The solar arrays, extended beyond the diameter of the reflector, are fixed hemi-cylinders consisting of 16 flat panels each. The communications system is an integrated multifrequency RF repeater capable of receiving up to 3 signals in any of 4 frequency bands (C, S, L, VHF) and retransmitting them on any desired frequency in 4 frequency bands (C, S, L, UHF). Results of the Tracking and Data Relay Experiment with GEOS-3 are summarized. Accuracies of 0.1 to 0.2 deg have been maintained in the programmed mode of tracking using the ATS-6 Digital Operational Controller, and communications links for the relay of 1.56 kilobit telemetry data from GEOS and for acquisition of range and range rate data performed as predicted or better.

Redisch, W. N.↗
NASA NTRS1976

Remote sensing of atmospheric pollutant gases using an infrared heterodyne spectrometer

Remote sensing of the concentration and vertical distribution of atmospheric gases using an infrared heterodyne spectrometer (IHS) has been investigated, and a dual (C-13)(O-16)2 laser multichannel IHS has been developed. Analyses of nadir thermal-radiance measurements from an aircraft at 10-km altitude and of solar absorption measurements from the ground indicate that initial applications of the IHS to tropospheric measurements of NH3 and O3 are feasible with measurement precisions ranging from 0.5 to 2 ppb and 20 to 30 ppb, respectively. These analyses have included effects of potential retrieval-error sources and have resulted in specifications of measurement modes, optimum signature lines, required system parameters, and expected sensitivities. Preliminary instrument performance data are presented.

Seals, R. K., Jr.↗