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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 775 records · Page 43

All sources NASA NTRS DOE OSTI

NASA NTRS1977

A review of advanced rotor research

This paper reviews advanced-rotor concepts including the advancing blade concept, the circulation control rotor, the X-wing rotor, the variable diameter rotor, the hingeless tilt rotor, the bearingless main rotor, the composite structures rotor, the variable geometry rotor, the multicyclic controllable pitch rotor, the multicyclic controllable twist rotor, and the live twist rotor. The rotor concepts are discussed in terms of performance (cruise speed, and lift/drag ratio) and dynamic loads and vibration.

Kelly, M. W.↗

NASA NTRS1976

Producibility aspects of advanced composites for an L-1011 Aileron

The design of advanced composite aileron suitable for long-term service on transport aircraft includes Kevlar 49 fabric skins on honeycomb sandwich covers, hybrid graphite/Kevlar 49 ribs and spars, and graphite/epoxy fittings. Weight and cost savings of 28 and 20 percent, respectively, are predicted by comparison with the production metallic aileron. The structural integrity of the design has been substantiated by analysis and static tests of subcomponents. The producibility considerations played a key role in the selection of design concepts with potential for low-cost production. Simplicity in fabrication is a major factor in achieving low cost using advanced tooling and manufacturing methods such as net molding to size, draping, forming broadgoods, and cocuring components. A broadgoods dispensing machine capable of handling unidirectional and bidirectional prepreg materials in widths ranging from 12 to 42 inches is used for rapid layup of component kits and covers. Existing large autoclaves, platen presses, and shop facilities are fully exploited.

Van Hamersveld, J.↗

NASA NTRS1977

Advanced spacecraft thermal control techniques

The problems of rejecting large amounts of heat from spacecraft were studied. Shuttle Space Laboratory heat rejection uses 1 kW for pumps and fans for every 5 kW (thermal) heat rejection. This is rather inefficient, and for future programs more efficient methods were examined. Two advanced systems were studied and compared to the present pumped-loop system. The advanced concepts are the air-cooled semipassive system, which features rejection of a large percentage of the load through the outer skin, and the heat pipe system, which incorporates heat pipes for every thermal control function.

Fritz, C. H.↗

NASA NTRS1977

Cost benefit study of advanced materials technology for aircraft turbine engines

The cost/benefits of eight advanced materials technologies were evaluated for two aircraft missions. The overall study was based on a time frame of commercial engine use of the advanced material technologies by 1985. The material technologies evaluated were eutectic turbine blades, titanium aluminide components, ceramic vanes, shrouds and combustor liners, tungsten composite FeCrAly blades, gamma prime oxide dispersion strengthened (ODS) alloy blades, and no coat ODS alloy combustor liners. They were evaluated in two conventional takeoff and landing missions, one transcontinental and one intercontinental.

Hillery, R. V.↗

NASA NTRS1977

Technology requirements for advanced earth-orbital transportation systems

Areas of advanced technology that are either critical or offer significant benefits to the development of future Earth-orbit transportation systems were identified. Technology assessment was based on the application of these technologies to fully reusable, single-stage-to-orbit (SSTO) vehicle concepts with horizontal landing capability. Study guidelines included mission requirements similar to space shuttle, an operational capability begining in 1995, and main propulsion to be advanced hydrogen-fueled rocket engines. Also evaluated was the technical and economic feasibility of this class of SSTO concepts and the comparative features of three operational take-off modes, which were vertical boost, horizontal sled launch, and horizontal take-off with subsequent inflight fueling. Projections of both normal and accelerated technology growth were made. Figures of merit were derived to provide relative rankings of technology areas. The influence of selected accelerated areas on vehicle design and program costs was analyzed by developing near-optimum point designs.

Haefeli, R. C.↗

NASA NTRS1977

Advanced supersonic propulsion study, phases 3 and 4

An evaluation of various advanced propulsion concepts for supersonic cruise aircraft resulted in the identification of the double-bypass variable cycle engine as the most promising concept. This engine design utilizes special variable geometry components and an annular exhaust nozzle to provide high take-off thrust and low jet noise. The engine also provides good performance at both supersonic cruise and subsonic cruise. Emission characteristics are excellent. The advanced technology double-bypass variable cycle engine offers an improvement in aircraft range performance relative to earlier supersonic jet engine designs and yet at a lower level of engine noise. Research and technology programs required in certain design areas for this engine concept to realize its potential benefits include refined parametric analysis of selected variable cycle engines, screening of additional unconventional concepts, and engine preliminary design studies. Required critical technology programs are summarized.

Allan, R. D.↗

NASA NTRS1977

Technology advancement of the static feed water electrolysis process

A program to advance the technology of oxygen- and hydrogen-generating subsystems based on water electrolysis was studied. Major emphasis was placed on static feed water electrolysis, a concept characterized by low power consumption and high intrinsic reliability. The static feed based oxygen generation subsystem consists basically of three subassemblies: (1) a combined water electrolysis and product gas dehumidifier module; (2) a product gas pressure controller and; (3) a cyclically filled water feed tank. Development activities were completed at the subsystem as well as at the component level. An extensive test program including single cell, subsystem and integrated system testing was completed with the required test support accessories designed, fabricated, and assembled. Mini-product assurance activities were included throughout all phases of program activities. An extensive number of supporting technology studies were conducted to advance the technology base of the static feed water electrolysis process and to resolve problems.

Schubert, F. H.↗

NASA NTRS1978

Projected role of advanced computational aerodynamic methods at the Lockheed-Georgia company

Experience with advanced computational methods being used at the Lockheed-Georgia Company to aid in the evaluation and design of new and modified aircraft indicates that large and specialized computers will be needed to make advanced three-dimensional viscous aerodynamic computations practical. The Numerical Aerodynamic Simulation Facility should be used to provide a tool for designing better aerospace vehicles while at the same time reducing development costs by performing computations using Navier-Stokes equations solution algorithms and permitting less sophisticated but nevertheless complex calculations to be made efficiently. Configuration definition procedures and data output formats can probably best be defined in cooperation with industry, therefore, the computer should handle many remote terminals efficiently. The capability of transferring data to and from other computers needs to be provided. Because of the significant amount of input and output associated with 3-D viscous flow calculations and because of the exceedingly fast computation speed envisioned for the computer, special attention should be paid to providing rapid, diversified, and efficient input and output.

Lores, M. E.↗

NASA NTRS1978

Technical and Economic Evaluation of Advanced Air Cargo Systems

The current air cargo environment and the relevance of advanced technology aircraft in enhancing the efficiency of the 1990 air cargo system are discussed. NASA preliminary design studies are shown to indicate significant potential gains in aircraft efficiency and operational economics for future freighter concepts. Required research and technology elements are outlined to develop a better base for evaluating advanced design concepts. Current studies of the market operation are reviewed which will develop design criteria for a future dedicated cargo transport. Design features desirable in an all-freighter design are reviewed. NASA-sponsored studies of large, distributed-load freighters are reviewed and these designs are compared to current wide-body aircraft. These concepts vary in gross takeoff weight from 0.5 Gg (one million lbs.) to 1.5 Gg (three million lbs.) and are found to exhibit economic advantages over conventional design concepts.

Whitehead, A. H., Jr.↗

NASA NTRS1976

Flight service evaluation of an advanced composite empennage component on commercial transport aircraft. Phase 1: Engineering development

The empennage component selected for this program is the vertical fin box of the L-1011 aircraft. The box structure extends from the fuselage production joint to the tip rib and includes the front and rear spars. Various design options were evaluated to arrive at a configuration which would offer the highest potential for satisfying program objectives. The preferred configuration selected consists of a hat-stiffened cover with molded integrally stiffened spars, aluminum trussed composite ribs, and composite miniwich web ribs with integrally molded caps. Material screening tests were performed to select an advanced composite material system for the Advanced Composite Vertical Fin (ACFV) that would meet the program requirements from the standpoint of quality, reproducibility, and cost. Preliminary weight and cost analysis were made, targets established, and tracking plans developed. These include FAA certification, ancillary test program, quality control, and structural integrity control plans.

Ary, A.↗

NASA NTRS1978

Advanced Multispectral Scanner (AMS) study

The status of aircraft multispectral scanner technology was accessed in order to develop preliminary design specifications for an advanced instrument to be used for remote sensing data collection by aircraft in the 1980 time frame. The system designed provides a no-moving parts multispectral scanning capability through the exploitation of linear array charge coupled device technology and advanced electronic signal processing techniques. Major advantages include: 10:1 V/H rate capability; 120 deg FOV at V/H = 0.25 rad/sec; 1 to 2 rad resolution; high sensitivity; large dynamic range capability; geometric fidelity; roll compensation; modularity; long life; and 24 channel data acquisition capability. The field flattening techniques of the optical design allow wide field view to be achieved at fast f/nos for both the long and short wavelength regions. The digital signal averaging technique permits maximization of signal to noise performance over the entire V/H rate range.

Source record↗

NASA NTRS1978

Technology requirements for advanced earth orbital transportation systems. Volume 2: Summary report

The results of efforts to identify the technology requirements for advanced earth orbital transportation systems are reported. Topics discussed include: (1) design and definition of performance potential of vehicle systems, (2) advanced technology assessment, and (3) extended performance. It is concluded that the horizontal take-off concept is the most feasible system considered.

Hepler, A. K.↗

NASA NTRS1978

Aerodynamic design and performance testing of an advanced 30 deg swept, eight bladed propeller at Mach numbers from 0.2 to 0.85

The increased emphasis on fuel conservation in the world has stimulated a series of studies of both conventional and unconventional propulsion systems for commercial aircraft. Preliminary results from these studies indicate that a fuel saving of from 15 to 28 percent may be realized by the use of an advanced high speed turboprop. The turboprop must be capable of high efficiency at Mach 0.8 above 10.68 km (35,000 ft) altitude if it is to compete with turbofan powered commercial aircraft. An advanced turboprop concept was wind tunnel tested. The model included such concepts as an aerodynamically integrated propeller/nacelle, blade sweep and power (disk) loadings approximately three times higher than conventional propeller designs. The aerodynamic design for the model is discussed. Test results are presented which indicate propeller net efficiencies near 80 percent were obtained at high disk loadings at Mach 0.8.

Black, D. M.↗

NASA NTRS1978

Advanced program weight control system

The design and implementation of the Advanced Program Weight Control System (APWCS) are reported. The APWCS system allows the coordination of vehicle weight reduction programs well in advance so as to meet mandated requirements of fuel economy imposed by government and to achieve corporate targets of vehicle weights. The system is being used by multiple engineering offices to track weight reduction from inception to eventual production. The projected annualized savings due to the APWCS system is over $2.5 million.

Derwa, G. T.↗

NASA NTRS1977

NASA's advanced control law program for the F-8 digital fly-by-wire aircraft

This paper briefly describes the NASA F-8 Digital Fly-By-Wire (DFBW) and Langley Research Center's role in investigating and promoting advanced control laws for possible flight experimentation and also provides a brief description of the Phase II DFBW F-8 aircraft and its control system. Some of the advanced control law study objectives and guidelines are discussed, and some mathematical models which are useful in the control analysis problem are provided.

Elliott, J. R.↗

NASA NTRS1978

Performance and economics of advanced energy conversion systems for coal and coal-derived fuels

The desire to establish an efficient Energy Conversion System to utilize the fossil fuel of the future - coal - has produced many candidate systems. A comparative technical/economic evaluation was performed on the seven most attractive advanced energy conversion systems. The evaluation maintains a cycle-to-cycle consistency in both performance and economic projections. The technical information base can be employed to make program decisions regarding the most attractive concept. A reference steam power plant was analyzed to the same detail and, under the same ground rules, was used as a comparison base. The power plants were all designed to utilize coal or coal-derived fuels and were targeted to meet an environmental standard. The systems evaluated were two advanced steam systems, a potassium topping cycle, a closed cycle helium system, two open cycle gas turbine combined cycles, and an open cycle MHD system.

Corman, J. C.↗

NASA NTRS1978

Econometric comparisons of liquid rocket engines for dual-fuel advanced earth-to-orbit shuttles

Econometric analyses of advanced Earth-to-orbit vehicles indicate that there are economic benefits from development of new vehicles beyond the space shuttle as traffic increases. Vehicle studies indicate the advantage of the dual-fuel propulsion in single-stage vehicles. This paper shows the economic effect of incorporating dual-fuel propulsion in advanced vehicles. Several dual-fuel propulsion systems are compared to a baseline hydrogen and oxygen system.

Martin, J. A.↗

NASA NTRS1978

Advanced earth-to-orbit transportation vehicles and their propulsion systems

This paper identifies some of the advanced transportation systems and their associated propulsion systems being considered by MSFC for near-term missions (1980-1990), future missions (1990-2000), and far-term missions (post 2000). The near-term launch-vehicle considerations center around the growth Shuttle and the Shuttle-derived Heavy-Lift Launch Vehicle (HLLV) systems. The future and far-term considerations support the development of larger more advanced transportation systems. In such cases, the changing nature of the propulsion requirements needed by the launch vehicle are identified. The evolvement of chemical propulsion launch vehicles into the far future is prognosticated, and where applicable from a launch vehicle or propulsion viewpoint, orbit transfer vehicles are discussed.

Shelton, B. W.↗