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1990-02-01
Technical Paper
900326
B. E. Enga, J. W. Miller, D. Elliott, T. Topaloglu
Much attention has been paid to the emissions from diesel transit coaches culminating in the 1990 EPA bus standard.(1)* A primary pollutant that has been singled out for advanced controls is diesel particulate. In order to meet the low levels of particulate emissions in the standard, diesel particulate filters are one of the principle methods being studied. To this end, the Ministry of Transportation and Communications of Ontario and Engine Control Systems Ltd. entered into a cooperative development program for a low cost, simple and retrofitable diesel particulate control system.(2) The paper outlines the various components of the system and the results of field testing.
1990-04-01
Technical Paper
901051
Emray Goossen
The trend towards fly-by-wire flight controls, with ever increasing complexity, creates a heavy burden of proof-of-safety on the systems designer. Schedule pressures often compromise testing and generate increased risk. In this paper, we will present a concept that improves cost, schedule, and ultimately safety for future fly-by-wire control system development. The value of a tool that enhances the integration, verification, and validation (IV&V) processes will be addressed. The approach to developing a fully automated IV&V capability will be described. Finally, the results of the proof-of-concept demonstration on the X-31 program will be summarized.
1990-04-01
Technical Paper
901049
James A. Kocher
The Integrated Control and Avionics for Air Superiority (ICAAS) advanced development program objective is to develop, integrate, and demonstrate critical technologies which will enable USAF fighter aircraft to kill and survive when outnumbered by enemy aircraft during air combat engagements. A goal is to demonstrate that blue fighters can win aerial engagements when outnumbered as much as four to one by threats with capabilities anticipated in the year 1995-2000 timeframe. Primary emphasis is placed upon beyond-visual-range multiple target attack capability with provisions for effective transition to close-in combat. Information and recommended actions are computed to aid the pilot in selecting and executing the most effective attack and defend engagement options. The ICAAS system will attempt to maximize opportunities for missile launch against multiple enemy aircraft while maintaining options to defend when necessary.
1990-04-01
Technical Paper
901046
Darrell R. Branscome
On the 20th anniversary of the first Apollo-Lunar landing, 20 July 1989, President Bush outlined a long term national program for the Human Exploration of the Moon and Mars1. Extending the capabilities provided by Space Station Freedom, the President envisioned a return to the Moon to establish a permanent manned station, followed by manned missions to Mars early in the next century. These are bold new goals for the U.S. Space Program. They are, however, built on a solid technical programmatic planning base. These demanding but realistic mission objectives reflect the highest technical and engineering capabilities residing within the government and our aerospace industry. The intent of this paper is to provide insight into advanced transportation planning and the systems that must evolve to support these long-term mission requirements.
1990-04-01
Technical Paper
901048
Fred Ching
Abstract Composite actuators for airborne systems have demonstrated up to 47% weight savings as compared to conventional (metal) actuators while satisfying all critical tests (proof, impulse and life cycling, temperature shock, vibration, burst) based on a high performance aircraft specification (F/A-18), Figure 1. In addition, the composite actuator is “jam resistant”, satisfying a survivability requirement for the Navy/Naval Weapons Center (NWC).
1990-04-01
Technical Paper
901039
T. Krepec, A. I. Georgantas, M. Taylor, C. H. To
A new family of low cost electronic fuel control units is being proposed for small gas turbine engines of remotely piloted vehicles and auxiliary power units. It has a modular design incorporating an electronically actuated metering valve which can be matched with various types of differential pressure valves controlling the pressure drop across the metering valve. Four different configurations are proposed: metering valve only, metering valve with diaphragm type differential pressure valve, metering valve with bypass valve and double valve configuration, the latter with a back-up capability. These configurations can satisfy various demands from gas turbine engine producers. Some components of automotive fuel injection system could be used to reduce the cost of these units as well as components from the DP-F2 fuel control which has been in production for a long time. This adds to the confidence of the reliability and durability of this new design.
1990-04-01
Technical Paper
901044
William J.D. Escher, Paul N. Herr, Frank W. Stephenson
The Earth-to-Orbit (ETO) Propulsion Program was initiated in 1988 as a major element of NASA's Civil Space Technology Initiative (CSTI), a set of some ten different program elements directed to the revitalization of the U.S.'s space technology resource upon which future spaceflight missions will be able to draw. Through the ETO Program the Nation is investing $ 20-30 million/year in the development and demonstration of needed design and analysis tools and computational means, advanced materials and processes, and very advanced systems-synthesis methodologies to enable advanced, highly reliable liquid hydrogen- and hydrocarbon-fueled, pump-fed rocket engines to be acquired and operated at significantly reduced technical risk and cost (e.g., vis-a-vis the SSME).
1990-04-01
Technical Paper
901037
Jemei Chang
The strength of glass fiber used in composite leaf springs was measured after and before the manufacturing process. From the experimental data, the Weibull distribution parameters were estimated by graphical regression, non-linear regression and maximum likelihood methods. Correlations between the experimental data and distribution functions based on different regression techniques were compared. The fibers were found to have lost approximately 30% and 25% of their original strength after the fabricating and the molding process, respectively. Additional experiments showed that the impregnation system, the wipe-off system and the creel surface contact all adversely affect the fiber strength. Fractography and the introduction of flaws on glass fiber samples confirmed that surface defects were caused by the processing and resulted in the strength loss.
1990-04-01
Technical Paper
901038
Robert C. Edgell
The development and implementation of the Synchronous Process is a step beyond Just-In-Time production systems for manufacturing operations. This new concept includes the focused factory, supplier development, and office synchronization processes in one total system. This system is designed to eliminate all forms of waste, product focuses the entire organization, and measures success in terms of customer satisfaction. This paper explains this process and shows the results achieved to date.
1990-04-01
Technical Paper
901035
Harry J. King, Peter F. LeFort
Abstract The first production configured Head-Up Display (HUD) was introduced in the United States in the 1988 Oldsmobile Cutlass Supreme Indianapolis 500 Pace Car Parade Convertibles. The HUD used in this Pace Car was designed, fabricated and installed by a team from Oldsmobile, CPC Advanced Engineering, Delco and Hughes in less than four months. This paper is a brief account of the technical, business and management decisions that helped expedite this project.
1990-04-01
Technical Paper
901036
Gary G. Tibbetts
Abstract Less expensive carbon fibers may become available in the future by production from vapor phase hydrocarbons. In this process, iron based catalytic particles of a few nanometers diameter grow carbon filaments when they are exposed to hydrocarbon vapor near 1000°C. These filaments are of nanometer diameter but may be thickened by deposition of carbon from the vapor phase. The mechanical properties of the fibers made by this processs resemble those of medium quality commercial fibers; the electrical and thermal conductivities are also desirable.
1990-04-01
Technical Paper
901031
GORDON C. TAMPLIN, DAVID L. HAMMOND, RAYMOND E. FREDETTE
An in-house design study was conducted by Wright Research and Development Center in 1988-1989. The goal was to produce an initial assessment of key capability needs, design features, and technology requirements of an Air Force Multi-Role (Defensive Counter Air and Battlefield Air Interdiction) Short Take-off and Vertical Landing (STOVL) Fighter. This paper summarizes some of the results of that study. The composite design mission and preliminary design goals are discussed. The resulting aircraft designs are presented and key design considerations are pointed out. Some general insights into the STOVL design drivers and requirements sensitivities are discussed.
1990-04-01
Technical Paper
901033
Jack G. McArdle, C. Frederic Smith
SUMMARY Flow in a generic ventral nozzle system was studied experimentally and analytically with the PARC3D computational fluid dynamics program (a full Navier-Stokes equations solver) in order to evaluate the program's ability to predict system performance and internal flow patterns. A generic model of a tailpipe with a rectangular ventral nozzle, about one-third of full size, was tested with unheated air at steady-state pressure ratios up to 4.0. The end of the tailpipe was closed to simulate a blocked exhaust nozzle. Measurements showed about 5½-percent flow-turning loss and reasonable nozzle performance coefficients. The flow turned more than the designed 90°, causing an aftward axial component in the total thrust. Flow behavior into and through the ventral duct is discussed and illustrated with paint streak flow visualization photographs. PARC3D graphic images are shown for comparison with the experiment photographs.
1990-04-01
Technical Paper
901027
G. Carrese, T. Krepec, C. H. To
The potential benefits of digital electronic controls, including increased flexibility and lower cost, have not yet been fully applied to the small gas turbine engines of remotely piloted vehicles. For these applications, the need for low cost is a strong factor in design. To address this situation, a new, simple and inexpensive electronically controlled metering system for small gas turbine engines is proposed. The system incorporates a diaphragm type valve keeping a constant differential pressure across a stepper motor actuated metering valve. To optimize the design, mathematical models were created for computer simulation. Experimental tests performed on a prototype showed that it can adequately meet the fuel schedules of small gas turbines. The simulation models were validated against the test results and were used in design optimization.
1990-04-01
Technical Paper
901028
Giovanni Torella
Summary The problems connected with the simulation of APUs with different configuration are considered. The techniques studied allow to set up end to develop fast, flexible and reliable numerical computer codes. The paper shows the results of calculations for both design-point and off design conditions. Moreover diagnostic and fault simulation are carried out and discussed. At last direct and inverse transient working simulations have been performed.
1990-04-01
Technical Paper
901024
John Wooten, Arthur Weiss
Current goals for Earth-to-Orbit transportation are to reduce the cost of payloads to low earth orbit by a factor of ten compared to existing launch capabilities. This objective translates directly to all parts of the launch vehicle system but especially propulsion. Rocketdyne is meeting this challenge today by designing an engine system which can be produced at one-tenth the cost of the current Space Shuttle Main Engine. The results from this on-going effort to design and build a high reliability, low cost engine are reviewed in this paper.
1990-04-01
Technical Paper
901065
W. Harry Rudy
To achieve customer satisfaction over the life of a product, the prediction of that product's behavior in the customers' hands is absolutely essential. Reliability must be designed into the product as it is developed. This paper presents a method for accelerating test time-to-failure, while demonstrating the product's reliability. The methodologies described uphold the basic principals of reliability and offer the capability of minimizing test time while maximizing the ability to assure performance and durability.
1990-04-01
Technical Paper
901064
Nobuhiro Tanatsugu
The present paper addresses the development study of expander cycle Air Turbo-Ramjet (ATR) conducting in the Institute of Space and Astronautical Science (ISAS) in cooperation with Ishikawajima-Harima Heavy Industries Co., LTD(IHI). The analytical study on the various cycle derivatives of ATR engine applying for a space plane has been presented in IAF congress held in Brighton 1987. Of which we selected the expander cycle ATR with intake air cooler and made the long-term research plan to assess its feasibility. The development study is going to be implemented by three steps of verification test, (1) sea level static test, (2) hypersonic simulation test with wind tunnel and (3) actual flight test with a flying test bed. We are now in the first step which was initiated in 1988 and will be accomplished in 1991.
1990-04-01
Technical Paper
901066
Valery V. Lazarev
A brief review of investigations in the field of advanced structural concepts and structure member with the aim of making a forecast of hypersonic and aerospace vehicle development is given. Methods of material choice for a hot and thermal protected structure is discussed. The data concerning experimental investigations of structural concepts and structure members by using large-scale models are presented.
1990-04-01
Technical Paper
901058
Paul T. Soderman
Current empirical models of several turbojet acoustic sources have been incorporated in a scheme for prediction of conventional or STOVL jet aircraft noise. The acoustic sources modeled were jet mixing noise, core noise, and broadband shock noise. The free-jet noise was then coupled with a new empirical equation for ground interaction noise generated by a vertically impinging jet. The modification of out-of-ground free-jet acoustic directivity pattern by a Harrier type nozzle installation was incorporated in the prediction of STOVL noise. The jet/ground interaction noise prediction is the result of a flight test of the NASA Ames Harrier jet aircraft that was operated in vertical takeoff and landing. Acoustic data measured with an array of ground level microphones showed ground amplification of jet noise that peaked at a jet height equal to 18 nozzle diameters. At jet heights below 18 nozzle diameters, far-field ground level noise decreased.
1990-04-01
Technical Paper
901055
David F. Pickett
Nickel alkaline batteries used in spacecraft electrical power subsystems are either nickel-cadium or nickel-hydrogen. The nickel-cadmium battery has been used since the beginning of the space program, while the nickel-hydrogen battery is a relative newcomer. Both couples are still used extensively, and recent advances in each have been documented. There are advantages and disadvantages in the use of either chemistry, but the nickel-hydrogen battery appears to be more attractive for longer life and higher specific energy for payloads greater than one kilowatt.
1990-04-01
Technical Paper
901062
Robert E. Childs
The turbulent impinging jet flows associated with vertical or short take-off and landing (VTOL) aircraft hovering in ground effect can have a critical effect on aircraft performance, and they are modeled very poorly by existing models. Three flow phenomena representative of VTOL ground effects flows, the upwash fountain, the ground vortex, and the impingement zone of a round jet, are considered. Extensions to the k-ϵ model are presented which are designed to account for streamline curvature, large scale mixing, and anisotropy. The extensions significantly improve the model's ability to predict some aspects of these flows. Requirements for further model development are identified.
1990-04-01
Technical Paper
901060
Victor R. Corsiglia, Douglas A. Wardwell, Richard E. Kuhn
A series of tests has been completed in which suckdown and fountain forces and pressures were measured on circular plates and twin-tandem-jet generic STOVL (short takeoff and vertical landing) configurations. The tests were conducted using a small-scale hover rig, for jet pressure ratios up to 6 and jet temperatures up to 700°F. The measured suckdown force on a circular plate with a central jet was greater than that found with a commonly used empirical prediction method. The present data showed better agreement with other sets of data. The tests of the generic STOVL configurations were conducted to provide force and pressure data with a parametric variation of parameters so that an empirical prediction method could be developed. The effects of jet pressure ratio and temperature were found to be small. Lift improvement devices were shown to substantially reduce the net suckdown forces. Paper to be presented at SAE Aerospace Meeting, Dayton, Ohio, April 24-27, 1990
1990-04-01
Technical Paper
901053
Khushrow K. Press, J. Douglass Briscoe
Thermal batteries are primary reserve energy sources consisting of an alkali-metal and a transition metal chalcogenide electrochemical couple in a fused salt electrolyte. The electrolyte is solid and non-conducting at ambient temperatures and melts after integral pyrotechnic heat sources are ignited by a percussion primer or electro-explosive device. From their inception thermal batteries have proven superior for applications which require long shelf life, high reliability, imperviousness to dynamic environmental conditions and extremely high power. Primary applications include power for guidance and control, warhead fusing and telemetry for missiles. Recent improvements in specific energies and energy densities up to 70 Wh/kg and 155 Wh/l have opened new applications for aircraft emergency power and torpedo propulsion.
1990-04-01
Technical Paper
901056
Stephan M. Wolanczyk, Stephen P. Vukson
Increases in Air Force satellite power requirements dictate the need to increase battery useable energy density and lifetime over current levels. This paper will summarize efforts by Wright Research and Development Center to develop sodium-sulfur technology into a practical satellite energy storage system for GEO and LEO applications.
1990-04-01
Technical Paper
901052
Robert Higgins, Ken Kruger
Abstract A variety of high energy battery types are available to design engineers, although not all are well characterized in the general literature. Most of these new systems are based on lithium anodes and are capable of energy densities as high as 700 Wh/Kg and shelf losses of less than 3% per year. Accompanying this high energy density however are other less desirable characteristics. Certain lithium systems experience voltage sag following storage. Most have at least some safety considerations during abuse. This paper presents general information on the two highest energy lithium systems, as well as one aqueous system which, while much older, is still capable of reasonably high energy densities.
1990-04-01
Technical Paper
901054
Richard A. Flake, Michael D. Eskra
Most aircraft in the U. S. Air Force inventory currently use vented nickel-cadmium (Ni-Cd) batteries for the main aircraft d.c. electrical power system and emergency power as well as other functions such as powering lights and instruments prior to engine starting/ignition. The major concerns of todays users are the high maintenance requirements, low reliability of vented NiCd battery systems and lack of a built-intest capability to check the battery state of health prior to flight. This paper will summarize efforts by the Wright Research and Development Center to develop maintenance free battery technologies for current and future aircraft applications.
1990-10-01
Technical Paper
901176
Goro Miyazaki, Shinichi Aoyagi
This paper offers a brief explanation of Isuzu Transport Auto Control (I-TAC), a system used to accurately collect and control information in-transit. I-TAC was developed as a means to meet needs for transportation by truck.
1990-07-01
Technical Paper
901205
Keiji Nitta, Koji Otsubo, Seishiro Kibe, Haruhiko Ohja
Many research activities relating the environment control and life support systems to be used in space have been conducted and continued in Japan since 1982 in order to obtain his own manned flight technologies for future Japanese missions. Research and development activities are able to be divided in two phases according mission scheduling such as JEM development to be used in International Space Station now going on and the future Japanese space infrastructures, for examples, Japanese Space Station and Lunar Base. Temperature, humidity, total atmospheric pressure and partial pressure of oxygen and carbon dioxide, necessary for all living things, are to be controlled by the environment control function.
1990-07-01
Technical Paper
901200
John E. Greenleaf
Maintenance of rest and exercise performance are prime requirements for all astronauts during flight, not only for maintaining day-to-day productivity, but also for coping with unlikely emergencies; e.g., emergency egress from the Shuttle upon landing. Indirect estimates of submaximal work capacity (oxygen uptake) made from changes in the heart rates of 27 Apollo astronauts (<15-day flights) indicated a reduction in work capacity (maximal oxygen uptake) of 17% to 21%. This percentage decrease was similar to that measured in middle-aged men after 21 to 30 days of -6° head-down bed-rest deconditioning without exercise training. Heart-rate changes during submaximal exercise in the nine Skylab astronauts suggested that they were better able to maintain their work capacity because of longer and more intensive in-flight exercise training.
Viewing 1 to 30 of 27568