Advanced design concepts for high speed bearings
High speed roller bearing design with long fatigue life and weight reduction for high temperature operation in inert environment
Scibbe, H. W.↗
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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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Frozen propellant - A booster concept
Frozen bipropellants as self supporting structural member for booster weight reduction, considering mechanical and thermal properties and melting rate requirement
Staylor, W. F.↗
Airflow distribution control for improved turbine engine performance
Control allows significant diffuser length and weight reduction, reduces combustor exhaust emissions during engine idle, and improves combustor altitude relight capability.
Juhasz, A. J.↗
The use of the transmission windows of the Fabry-Perot interferometer in the detection of Raman scattered radiation from atmospheric gases.
Demonstration that the use of the Fabry-Perot interferometer as a filter with transmission windows occurring at regular intervals in wave numbers provides a highly sensitive method for detection of atmospheric gases using their rotational Raman spectra excited by a suitable laser. Some of the operating advantages include signal gains of several orders of magnitude, a simple direct interpretation of the results in terms of the density and types of the gaseous constituents, size and weight reductions from conventional apparatus, ease of operation, and relative freedom from interference from other molecules in the scattering volume. This method is compared with the techniques that have been discussed in the literature by other workers in the field.
Smith, W. H.↗
Space shuttle auxiliary propulsion system design study. Phase D report: Oxygen-hydrogen special RCS studies
Two alternate oxygen-hydrogen auxiliary propulsion system concepts for use with the space shuttle vehicle were evaluated. The two concepts considered were: (1) gaseous oxygen-hydrogen systems with electric or hydraulic motor driven pumps to provide system pressure and (2) liquid oxygen-hydrogen systems which delivered propellants to the engines in a liquid state without the need for pumps. The various means of implementing each of the concepts are compared on the basis of weight, technology requirements, and operational considerations. It was determined that the liquid oxygen-hydrogen system concepts have the potential to produce substantial weight reductions in the space shuttle orbiter total impulse range.
Baumann, T. L.↗
Cryogenic liquid O2/H2 reaction control systems for Space Shuttle.
A Space Shuttle liquid oxygen/hydrogen reaction control system design analysis has been performed. The system concept considered eliminates propellant conditioning equipment and delivers the propellants to the engines in a liquid rather than a gaseous state. This paper provides system design analyses results and compares various means of implementing the concept on the basis of weight, technology requirements, and operational considerations. Additionally, weight comparisons are made between cryogenic oxygen/hydrogen system requirements. These comparisons show that the liquid oxygen/hydrogen system concept could effect marked weight reductions in the Space Shuttle orbiter total impulse range.
Kelly, P. J.↗
Lead-oxygen closed-loop battery system
Calculations show that battery can deliver up to 35 watt-hours per pound, conventional lead-acid batteries deliver 10 to 15 watt-hours per pound. Weight reduction is due to replacement of solid lead-peroxide electrodes with metal current-collector screen, catalyst, and Teflon membrane.
Britz, W. J.↗
Dynamics of Flexible Spinning Satellites with Radial Wire Antennas
A dynamic analysis is presented for a spin stabilized spacecraft employing four radial wire antennas with tip masses, a configuration first employed in the IMP-J spacecraft. The use of wires in place of the usual booms represents the ultimate in weight reduction at the expanse of flexibility. The satellite is modelled as a 14 degree of freedom system, and the linearized equations of motion are found. The lowest order vibrational modes and natural frequencies of the gyroscopically coupled system are then determined. Because the satellite spin rate is decreased by antenna deployment, a spin-up maneuver is needed. The response of the time varying mode equations during spin-up is found, for the planar modes, in terms of Bessel functions and a Struve function of order -1/4. Because tables of the latter are not readily available, the particular solution is expressed in various forms including an infinite series of Bessel functions and a particularly useful asymptotic expansion.
Longman, R. W.↗
Low voltage 30-cm ion thruster development
The basic goal was to advance the development status of the 30-cm electron bombardment ion thruster from a laboratory model to a flight-type engineering model (EM) thruster. This advancement included the more conventional aspects of mechanical design and testing for launch loads, weight reduction, fabrication process development, reliability and quality assurance, and interface definition, as well as a relatively significant improvement in thruster total efficiency. The achievement of this goal was demonstrated by the successful completion of a series of performance and structural integrity (vibration) tests. In the course of the program, essentially every part and feature of the original 30-cm Thruster was critically evaluated. These evaluations, led to new or improved designs for the ion optical system, discharge chamber, cathode isolator vaporizer assembly, main isolator vaporizer assembly, neutralizer assembly, packaging for thermal control, electrical terminations and structure.
King, H. J.↗
Flight service evaluation of PRD-49/epoxy composite panels in wide-bodied commercial transport aircraft
Fairing panels were fabricated to evaluate the fabrication characteristics and flight service performance of PRD-49 (Kevlar-49) a composite reinforcing material and to compare it with the fiberglass which is currently in use. Panel configurations were selected to evaluate the PRD-49 with two resin matrix materials in sandwich and solid laminate construction. Left and right hand versions of these configurations were installed on L-1011's which will accumulate approximately 3000 flight hours per year per aircraft. The direct substitution of PRD-49 for fiberglass produced a twenty-six percent weight reduction on the panel configurations. Examination of these panels revealed that there was no visible difference between the PRD-49 and adjacent fiberglass panels.
Wooley, J. H.↗
SEPS solar array design and technology evaluation
The technology developments required and a preliminary design of a lightweight 25 kW solar array for the solar electric propulsion stage (SEPS) have been defined. The requirements for a 65 W/Kg SEPS solar array system requires significant component weight reductions over present state-of-the-art flexible solar arrays in both electrical and structural-mechanical designs. A requirement for operation from 0.3 au to 6.0 au presents a wide range of temperature environments as well as severe combined thermal/vacuum/UV radiation environments. Additional requirements are capability for partial array retraction operation, and capability for full retraction and automatic preloading for survival of the Shuttle reentry environment. An assessment of current lightweight flexible solar array technology is made against the SEPS solar array requirements and new technology requirements are defined. A preliminary design and the operating characteristics of a flat-fold solar array system meeting the SEPS requirements is presented. A full-width, 10-ft-tall functional array model, including representative welded electrical modules and a model astromast, was fabricated and tested.
Elms, R. V., Jr.↗
Composite stacked moly-permalloy cores
Composite core comprised of two sections, each having different permeability, results in size and weight reduction. One section provides sufficient induction under light loading conditions, while other section offers minimum inductance under heavy loading.
Mclyman, W. T.↗
Space Shuttle Trace Gas Analyzer
A Trace Gas Analyzer (TGA) with the ability to detect the presence of toxic contaminants in the Space Shuttle atmosphere within the subparts-per-million range is under development. The design is a modification of the miniaturized Gas Chromatograph-Mass Spectrometer (GCMS) developed for the Viking Mars Lander. An ambient air sample is injected onto the GC column from a constant volume sample loop and separated into individual compounds for identification by the MS. The GC-MS interface consists of an effluent divider and a silver-paladium separator, an electrochemical cell which removes more than 99.99% of the hydrogen carrier gas. The hydrogen is reclaimed and repressurized without affecting the separator efficiency, a feature which enables a considerable weight reduction in the carrier gas supply system.
Dencker, W.↗
The NASA structures and materials research program for supersonic cruise aircraft
The structures and materials part of the NASA Supersonic Cruise Aircraft Research (SCAR) program is reviewed. It is pointed out that in more than three years of work significant new technology has been generated. The aircraft configurations which are efficient aerodynamically have aeroelastic problems that must be alleviated by configuration changes, active controls, or additional structural mass. An approach involving the application of advanced composite materials has the highest potential for structural weight reduction. Attention is given to the structural concepts for an arrow-wing supersonic aircraft and the techniques used in the investigations. It is expected that continuing research in SCAR structures and materials should bring high payoffs in the late 1980s.
Cooper, P. A.↗
Goals for a future SST
The paper attempts to define a desirable and reachable goal for a second generation SST. Justifications for the need of an SST are considered as is the ecological impact of a second generation SST project. Required technology advances to reach the range of 6500 nautical miles are examined along with structural weight reduction and drag reduction. Possible performance improvements due to design modifications are discussed, and environmental problems are discussed in detail with emphasis on sonic booms.
Ferri, A.↗
Advanced composite rudders for DC-10 aircraft: Design, manufacturing, and ground tests
Design synthesis, tooling and process development, manufacturing, and ground testing of a graphite epoxy rudder for the DC-10 commercial transport are discussed. The composite structure was fabricated using a unique processing method in which the thermal expansion characteristics of rubber tooling mandrels were used to generate curing pressures during an oven cure cycle. The ground test program resulted in certification of the rudder for passenger-carrying flights. Results of the structural and environmental tests are interpreted and detailed development of the rubber tooling and manufacturing process is described. Processing, tooling, and manufacturing problems encountered during fabrication of four development rudders and ten flight-service rudders are discussed and the results of corrective actions are described. Non-recurring and recurring manufacturing labor man-hours are tabulated at the detailed operation level. A weight reduction of 13.58 kg (33 percent) was attained in the composite rudder.
Lehman, G. M.↗
Design concepts for a composite door frame system for general automotive applications
Conceptual design, manufacturing process, and costs are explored to determine the feasibility of replacing present steel parts in automotive door structures with various composite materials. The problems of conforming to present anti-intrusion specifications with advanced materials are examined and discussed. Modest weight reductions, at competitive costs, were identified for the utilization of specific composite materials in automotive door structures.
Tauber, J. A.↗
NASA Office of Aeronautical and Space Technology Summer Workshop. Volume 6: Structures and dynamics panel
Structural requirements for future space missions were defined in relation to technology needs and payloads. Specific areas examined include: large area space structures (antennas, solar array structures, and platforms); a long, slender structure or boom used to support large objects from the shuttle or hold two bodies apart in space; and advanced composite structures for cost effective weight reductions. Other topics discussed include: minimum gage concepts, high temperature components, load and response determination and control, and reliability and life prediction.
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