SEARCH · Engineering Papers
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.
Miniaturized transducers are fabricated from commercially available four-arm semiconductor gages; transducers are connected as bridge circuit and mounted on internal face of small diaphragm. Jacket made of conductive plastic may be needed to avoid buildup or static charges.
Results are presented of testing performed to measure the effects of material outgas products on the reflectances of ultraviolet-region mirrors. These tests were to provide data on changes of ultraviolet reflectances of first-surface mirrors which had been exposed to the outgas products of selected materials under specific time and thermal-vacuum conditions. The requirement for such data was based on the extreme sensitivity of the sophisticated optical instruments in the Skylab mission's Apollo Telescope Mount (ATM) to condensed outgas products from materials, and on the desire to insure that no serious hazard of contaminating these instruments existed.
An inviscid technique for designing forebodies which produce uniformly precompressed flows at the inlet entrance for bottom-mounted scramjets has been developed so that geometric constraints resulting from design trade-offs can be effectively evaluated. The flow fields resulting from several forebody designs generated in support of a hypersonic research airplane conceptual design study have been analyzed in detail with three-dimensional characteristics calculations to verify the uniform flow conditions. For the designs analyzed, uniform flow is maintained over a wide range of flight conditions (Mach number equals 4 to 10; angle of attack equals 6 deg to 10 deg) corresponding to scramjet operation flight envelope of the research airplane.
A shock mount for installing electrical components on circuit boards is described. The shock absorber is made of viscoelastic material which interconnects the electrical components. With this system, shocks imposed on one component of the circuit are not transmitted to other components. A diagram of a typical circuit is provided.
An approximately 1/30th-scale model of a CTOL aircraft designed for efficient cruise between Mach 0.9 and 0.98 was tested in the Lewis Research Center's 8- by 6-Foot Supersonic Wind Tunnel. Aft-fuselage axial force and pressure were measured for a series of locally area-ruled engine installations. Two flow-through nacelles with different exit diameters which simulated inlet mass flow ratios of 0.46 and 0.6 (based on maximum nacelle cross-sectional) area were investigated. Both an NACA-1 cowl and a blunter supercritical cowl were tested with these nacelles. Variations in the amount of local area ruling were investigated and an aft fuselage without nacelles was tested for reference. Results observed with flow-through nacelles indicate that efficient cruise may be obtained on this type of aircraft with aft-fuselage-mounted engine nacelles.
The installation procedures for surface-mounted flat conductor cable used in commercial and residential wiring are described.
The use of polymer adhesives for high reliability microcircuit applications is a radical deviation from past practices in electronic packaging. Bonding studies were performed using two gold-filled conductive adhesives, 10/90 tin/lead solder and Indalloy no. 7 solder. Various types of discrete components were mounted on ceramic substrates using both thick-film and thin-film metallization. Electrical and mechanical testing were performed on the samples before and after environmental exposure to MIL-STD-883 screening tests.
The operational testing and evaluation program is presented which was conducted on 20-ampere-hour nickel-cadmium (Ni-Cd) batteries for use on the Apollo telescope mount (ATM). The test program was initiated in 1967 to determine if the batteries could meet ATM mission requirements and to determine operating characteristics and methods. The ATM system power and charging power for the Ni-Cd secondary batteries is provided by a solar array during the 58-minute daylight portion of the orbit; during the 36-minute night portion of the orbit, the Ni-Cd secondary batteries will supply ATM system power. The test results reflect battery operating characteristics and parameters relative to simulated ATM orbital test conditions. Maximum voltage, charge requirements, capacity, temperature, and cyclic characteristics are presented.
The Skylab Apollo Telescope Mount (ATM) experiments, consisting of a white light coronagraph, four ultraviolet instruments, two X-ray telescopes and two hydrogen-alpha telescopes, observed the sun daily for nine solar rotations. The ATM instruments were individually larger, more complex, and provided better spatial resolution than previous solar satellite instruments. An additional major advantage of the telescope complex was its ability to simultaneously collect multispectral data of specific solar phenomena. To maximize the scientific benefits of the orbiting observatory, a coordinated observing program involving worldwide ground-based observatories was conducted. A description of the Skylab, the ATM, and the ATM experiments is given, and the daily process of flight planning and execution is described.
The Skylab Apollo Telescope Mount (ATM) experiments, consisting of a white light coronagraph, four ultraviolet instruments, two X-ray telescopes and two hydrogen-alpha telescopes, observed the sun daily for nine solar rotations. The results have only begun to be evaluated, but is is already apparent that many theories of solar physics will undergo significant revisions as results are further developed. The ATM instruments were individually larger, more complex, and provided better spatial resolution than previous solar satellite instruments. An additional major advantage of the telescope complex was its ability to simultaneously collect multispectral data for specific experiments. A description of the Skylab, the ATM and the ATM experiments will be given. The daily process of flight planning and execution will be described. Examples of scientific data and some preliminary findings will be presented.
An investigation is conducted of electric field patterns of a TE axial slot antenna which radiates through a dielectric window in a circular cylinder. The cylinder is partially coated with a dielectric layer. The investigation is to provide information regarding the effects of a high-temperature dielectric layer on the performance of antennas mounted on a space shuttle. Numerical results are presented for the far-field patterns. It is pointed out that the calculations show excellent agreement with experimental measurements.
Guide describes step-by-step process for installation of interior surface-mounted FCC used in commerical and residential buildings. Photographs illustrate how cable-riser and baseboard covers are installed as well as receptacle assembly and receptacle-cover replacement.
System consists of three major components: vertical deflector assembly, stationary reflector, and motor driven tracking mechanism. Deflector assembly directs incident incoming energy to a vertical direction, using series of horizontally mounted vanes. Energy is then redirected via reflector to fixed collector.
A prototype radio antenna of 10.4 meters diameter and 0.41 meter focal length, intended for use at the shortest radio wavelengths transmitted by the atmosphere, was successfully completed. The surface accuracy is at least four times better than that of any existing antenna in this size class: 50 micrometer rms. A prototype mount is being constructed and will be ready by early 1976. The development of an improved antenna of identical size, but heavier weight has been continued.
This report is a compilation of bibliographies from the principal investigator groups of the Apollo Telescope Mount (Skylab solar observatory facility) which gathered data from May 28, 1973, to February 8, 1974. The analysis of these data is presently under way and is expected to continue for several years. The publications listed in this report are divided into thy; following categories: (1) Journal Publications, (2) Journal Publications Submitted, (3) Other Publications, (4) Presentations--National and International Meetings, and (5) Other Presentations. An author index is also included.
A thrust bearing consisting of pads mounted on resilient, metallic, cantilever beams is described and analyzed. Compliance and stiffness of the bearing assembly are discussed, and the effects of bearing design parameters on performance are shown. After the general analysis, a design example is presented for a flat sector-shaped gas bearing. A special case where zero axial movement of the runner can be obtained is pointed out.
High frequency radiation patterns of aircraft wing mounted antennas are analyzed. Basic antenna types using ray optical techniques are studied. The aircraft is modelled in its most basic form so that this study is applicable to general type aircraft. The fuselage is modelled as a perfectly conducting finite elliptic cylinder. The wings and horizontal and vertical stabilizers are modelled as perfectly conducting "n" sided flat plates that can be arbitrarily attached to the fuselage or to themselves. The antenna locations are assumed to be on the surfaces of the wings at locations removed from engines and stores such that these effects are negligible. Volumetric patterns are calculated for several aircraft. The validity of the solution is shown by comparing the results against scale model measurements. The application of this solution to practical airborne antenna problems has shown its versatility in designing antennas and predicting their radiation patterns in an accurate and efficient manner.
An aircraft crash location transmitter tuned to transmit on standard emergency frequencies is reported that is shock mounted in a sealed circular case atop the tail of an aircraft by means of a shear pin designed to fail under a G loading associated with a crash situation. The antenna for the transmitter is a metallic spring blade coiled like a spiral spring around the outside of the circular case. A battery within the case for powering the transmitter is kept trickle charged from the electrical system of the aircraft through a break away connector on the case. When a crash occurs, the resultant ejection of the case from the tail due to a failure of the shear pin releases the free end of the antenna which automatically uncoils. The accompanying separation of the connector effects closing of the transmitter key and results in commencement of transmission.