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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 523 records · Page 29
All sourcesNASA NTRSDOE OSTI
NASA NTRS1951

Control Performance of General Electric Fuel and Torque Regulator Operating on T31-3 Turbine-Propeller Engine in Sea-Level Test Stand

A .General Electric fuel and torque regulator was tested in conjunction with a T31-3 turbine-propeller engine in the sea-level static test stand at the NACA Lewis laboratory. The engine and control were operated over the entire speed range: 11,000 rpm, nominal flight idle, to 13,000 rpm, full power. Steady-state and transient data were recorded and are presented with a description of the four control loops being used in the system. Results of this investigation indicated that single-lever control operation was satisfactory under conditions of test. Transient data presented showed that turbine-outlet temperature did overshoot maximum operating value on acceleration but that the time duration of overshoot did not exceed approximately 1 second. This temperature limiting resulted from a control on fuel flow as a function of engine speed. Speed and torque first reached their desired values 0.4 second from the time of change in power-setting lever position. Maximum speed overshoot was 3 percent.

Oppenheimer, Frank L.↗
NASA NTRS1983

Turbulent flame propagation and combustion in spark ignition engines

Pressure measurements synchronized with high-speed motion-picture records of flame propagation have been made in a transparent-piston engine. The data show that the initial expansion speed of the flame front is close to that of a laminar flame. As the flame expands, its speed rapidly accelerates to a quasi-steady value comparable with that of the turbulent velocity fluctuations in the unburned gas. During the quasi-steady propagation phase, a significant fraction of the gas behind the visible front is unburned. Final burnout of the charge may be approximated by an exponential decay in time. The data have been analyzed in a model-independent way to obtain a set of empirical equations for calculating mass burning rates in spark-ignition engines. The burning equations contain three parameters: the laminar burning speed, a characteristic speed (uT), and a characteristic length (lT). The laminar burning speed is known from laboratory measurements. Tentative correlations relating uT and lT to engine geometry and operating variables have been derived from the engine data.

Beretta, G. P.↗
NASA NTRS1996

Development of the command data system and ground software for the SEDSAT-1 microsatellite

SEDSAT-1 is designed to be a low cost scientific satellite which is to be used to perform a minimum of five tasks which include: (1) the acquisition of a number of important parameters associated with the tethering processes from the payloads perspective (such as accelerations incurred and imaging data of the tether during deployment), (2) to act as a remote sensing platform for making measurements of the Earth's Atmosphere (allowing research to be performed in such areas as vertical lightning observation, visible light spectrography, and cloud cover studies, (3) to act as a general purpose amateur radio communication satellite relaying information back to earth, (4) to demonstrate the feasibility of the deployment in low earth orbit of advanced technology such as the Gallium Arsenide Solar Cells, Nickel Metal Hydride batteries, and multi-chip module technology and, (5) to support student's active participation in applying the disciplines of engineering and science to space-based hardware platforms. The project includes the Three-axis Accelerometer System, TAS, Experiment which is designed to report the accelerations that the satellite undergoes during the tethering operations and during the second phase of the mission when the free floating satellite comes in contact with orbit debris. The SEASIS (SEDS Earth, Atmosphere, and Space Imaging System) is another SEDSAT experiment designed to provide images of the tether during its deployment and the earth during the second phase of the mission. To control these experiments and virtually all other satellite operations the Command Data System, CDS is employed. This system utilizes a moderate complexity micro-controller controlled by tasks operating under a real-time operating system to dynamically monitor and control the satellite. The scope of this researchers efforts has been in the general area of coordinating and assisting the student researchers with the development of the CDS and ground station interfaces. This included the low level CDS hardware design and the formulization of a general software plan and schedule for both the CDS and ground station portions of the project.

Wells, B. Earl↗
NASA NTRS1954

Summary of Free-flight Performance of a Series of Ram-jet Engines at Mach Numbers from 0.80 to 2.20

Data obtained from the NACA air-launched ram-jet program are summarized with emphasis placed upon the transonic propulsive thrust potential of the engines. Data are presented for boosted and non-boosted engine configurations which incorporate a single-oblique-shock or double-oblique-shock diffuser designed for critical inlet operation at flight Mach numbers of 1.8 and 2.4, respectively. The engines are evaluated in terms of flight Mach number, mass-flow ratio, diffuser pressure recovery, combustion-chamber heat release, propulsive thrust, external drag, and specific impulse. From specific impulse considerations, it appears that for some air-launched missile applications the self-accelerating supersonic ram jet may have a lower gross weight than a rocket-boosted ram jet.

RESEARCH EQUIPMENT, FREE-FLIGHT↗
NASA NTRS1975

Vibration responses of test structure no. 1 during the Edwards Air Force Base phase of the national sonic boom program

In order to evaluate reaction of people to sonic booms of varying overpressures and time durations, a series of closely controlled and systematic flight test studies were conducted in the vicinity of Edwards AFB, California, from June 3 to June 23, 1966. The dynamic responses of several building structures were measured as a part of these studies, and the measurements made in a one-story residence structure (Edwards test structure No. 1) are presented. Sample acceleration and strain recordings are presented from F-104, B-58, and XB-70 sonic-boom exposures, along with tabulations of the maximum acceleration and strain values measured for each one of about 140 flight tests. These data are compared with similar measurements for engine noise exposures of the building during simulated landing approaches and takeoffs of KC-135 aircraft.

Findley, D. S.↗
NASA NTRS1975

Vibration Responses of Test Structure No. 2 During the Edward Air Force Base Phase of the National Sonic Boom Program

In order to evaluate reaction of people to sonic booms of varying overpressures and time durations, a series of closely controlled and systematic flight tests/studies were conducted from June 3 to June 23, 1966. The dynamic responses of several building structures were measured, with emphasis on a two-story residence structure. Sample acceleration and strain recordings from F-104, B-58, and XB-70 sonic boom exposures are included, along with tabulations of the maximum acceleration and strain values measured for each one of about 140 flight tests. These data are compared with similar measurements for engine noise exposures of the building during simulated landing approaches and takeoffs of KC-135 aircraft.

Findley, D. S.↗
NASA NTRS1983

Study for analysis of benefit versus cost of low thrust propulsion system

The benefits and costs associated with placing large space systems (LSS) in operational orbits were investigated, and a flexible computer model for analyzing these benefits and costs was developed. A mission model for LSS was identified that included both NASA/Commercial and DOD missions. This model included a total of 68 STS launches for the NASA/Commercial missions and 202 launches for the DOD missions. The mission catalog was of sufficient depth to define the structure type, mass and acceleration limits of each LSS. Conceptual primary propulsion stages (PPS) designs for orbital transfer were developed for three low thrust LO2/LH2 engines baselined for the study. The performance characteristics for each of these PPS was compared to the LSS mission catalog to create a mission capture. The costs involved in placing the LSS in their operational orbits were identified. The two primary costs were that of the PPS and of the STS launch. The cost of the LSS was not included as it is not a function of the PPS performance. The basic relationships and algorithms that could be used to describe the costs were established. The benefit criteria for the mission model were also defined. These included mission capture, reliability, technical risk, development time, and growth potential. Rating guidelines were established for each parameter. For flexibility, each parameter is assigned a weighting factor.

Hamlyn, K. M.↗
NASA NTRS1990

Vibration responses of two house structures during the Edwards Air Force Base phase of the national sonic boom program

The data are reproduced from NSBEO-1-67, which contains some preliminary results of the test program, and from NASA-Langley working papers 259 and 288 which are now out of print. Included are sample acceleration and strain recordings from F-104, B-58, and XB-70 sonic boom exposures, along with tabulations of the maximum acceleration and strain values measured for each one of about 130 flight tests. These data are compared with similar measurements for engine noise exposures of the building during simulated landing approaches and takeoffs of KC-135 aircraft.

Hubbard, Harvey H.↗
NASA NTRS1995

MagLifter Site Investigation and Implementation Strategies

MagLifter, as defined here, is an advanced, earth-bound catapult system to provide the initial lift for earth orbiting vehicles to reduce or eliminate the need for multistage propulsion, thus reducing the cost of orbital space flight. It is presumed that magnetic levitation will catapult the vehicle to a desired initial velocity sufficient for reaching orbit with the vehicles own engines. Of necessity, the system must be located on and around a mountain with sufficient relief to allow the catapult to accelerate the launch vehicle to a sufficient speed in the desired direction to allow it to reach orbit. Such a mountain site must meet criteria consistent with current and future space launch needs and conditions. It is the purpose of this report to set forth preliminary criteria for choosing a suitable maglifter site. The report is divided into four major sections: (1) Assumed Launch System and Flight Vehicle Characteristics; (2) Task 1.A - Initial Site Selection Criteria; (3) Conclusions; and (4) Appendix - Phases of the Site Selection Process.

Burke, Pamela↗
NASA NTRS1978

Large engines and vehicles, 1958

During the mid-1950s, the Air Force sponsored work on the feasibility of building large, single-chamber engines, presumably for boost-glide aircraft or spacecraft. In 1956, the Army missile development group began studies of large launch vehicles. The possibilities opened up by Sputnik accelerated this work and gave the Army an opportunity to bid for the leading role in launch vehicles. The Air Force had the responsibility for the largest ballistic missiles and hence a ready-made base for extending their capability for spaceflight. During 1958, actions taken to establish a civilian space agency, and the launch vehicle needs seen by its planners, added a third contender to the space vehicle competition. These activities during 1958 are examined as to how they resulted in the initiation of a large rocket engine and the first large launch vehicle.

Source record↗
NASA NTRS1983

Advanced automotive diesel assessment program

Cummins Engine Company completed an analytical study to identify an advanced automotive (light duty) diesel (AAD) power plant for a 3,000-pound passenger car. The study resulted in the definition of a revolutionary diesel engine with several novel features. A 3,000-pound car with this engine is predicted to give 96.3, 72.2, and 78.8 MPG in highway, city, and combined highway-city driving, respectively. This compares with current diesel powered cars yielding 41.7, 35.0, and 37.7 MPG. The time for 0-60 MPH acceleration is 13.9 sec. compared to the baseline of 15.2 sec. Four technology areas were identified as crucial in bringing this concept to fruition. They are: (1) part-load preheating, (2) positive displacement compounding, (3) spark assisted diesel combustion system, and (4) piston development for adiabatic, oilless diesel engine. Marketing and planning studies indicate that an aggressive program with significant commitment could result in a production car in 10 years from the date of commencement.

Sekar, R.↗
NASA NTRS1989

Relativistic neutrons in active galactic nuclei

The acceleration of protons to relativistic energies in active galactic nuclei leads to the creation of relativistic neutrons which escape from the central engine. The neutrons decay at distances of up to 1-100 pc, depositing their energies and momenta in situ. Energy deposition by decaying neutrons may inhibit spherical accretion and drive a wind, which could be responsible for the velocity fields in emission-line regions and the outflow of broad absorption line systems. Enhanced pressure in the neutron decay region may also help to confine emission line clouds. A fraction of the relativistic proton energy is radiated in gamma-rays with energies which may be as large as about 100,000 GeV.

Sikora, Marek↗
NASA NTRS1993

The Space Station Freedom microgravity environment

The SSF microgravity environment is discussed focusing on requirements derived from initial specifications proposed by the NASA Office of Space Science and Applications and on microgravity assessment methods including quasi-steady, structural dynamic, and vibroacoustic methods. Preliminary results indicate that the flight dynamics of the vehicle meet the requirements for both scientific and engineering communities, but that a number of vibroacoustic disturbance sources violate the criteria. The assessment updates along with planned on-orbit acceleration measurements and crew disturbance characterizations are being carried out to clearly define and understand the acceleration environment.

Del Basso, Steve↗
NASA NTRS2001

Training to Enhance Design Team Performance: A Cure for Tunnel Vision

Design Team performance is a function of the quality and degree of academic training and the cumulative, learned experience of the individual members of the team. Teamwork, leadership, and communications certainly are factors that affect the measure of the performance of the team, but they are not addressed here. This paper focuses on accelerating the learned experience of team members and describes an organizational approach that can significantly increase the effective experience level for any engineering design team. The performance measure of the whole team can be increased by increasing the engineering disciplines' cross awareness of each other and by familiarizing them with their affect at the system level. Discipline engineers know their own discipline well, but typically are not intimately familiar with their technical interaction with and dependencies on all the other disciplines of engineering. These dependencies are design integration functions and are worked out well by the discipline engineers as long as they are involved in the design of types of systems that they have experience with.

Parker, James W.↗
NASA NTRS2007

Computational Modeling Develops Ultra-Hard Steel

Glenn Research Center's Mechanical Components Branch developed a spiral bevel or face gear test rig for testing thermal behavior, surface fatigue, strain, vibration, and noise; a full-scale, 500-horsepower helicopter main-rotor transmission testing stand; a gear rig that allows fundamental studies of the dynamic behavior of gear systems and gear noise; and a high-speed helical gear test for analyzing thermal behavior for rotorcraft. The test rig provides accelerated fatigue life testing for standard spur gears at speeds of up to 10,000 rotations per minute. The test rig enables engineers to investigate the effects of materials, heat treat, shot peen, lubricants, and other factors on the gear's performance. QuesTek Innovations LLC, based in Evanston, Illinois, recently developed a carburized, martensitic gear steel with an ultra-hard case using its computational design methodology, but needed to verify surface fatigue, lifecycle performance, and overall reliability. The Battelle Memorial Institute introduced the company to researchers at Glenn's Mechanical Components Branch and facilitated a partnership allowing researchers at the NASA Center to conduct spur gear fatigue testing for the company. Testing revealed that QuesTek's gear steel outperforms the current state-of-the-art alloys used for aviation gears in contact fatigue by almost 300 percent. With the confidence and credibility provided by the NASA testing, QuesTek is commercializing two new steel alloys. Uses for this new class of steel are limitless in areas that demand exceptional strength for high throughput applications.

Source record↗
NASA NTRS2010

JANNAF Lessons Learned Panel: Selected Saturn V History

Pogo occurs when the natural frequency of a propellant feed line comes close to a readily excited rocket longitudinal structural vibration natural frequency. Maximum Pogo response corresponds to close tuning of the structural and hydraulic frequencies. On Saturn V, accelerations up to 17 g's (Zero To Peak) at the Launch Vehicle/Payload Interface and up to 34 g's at an Engine have been observed. Nicknamed Pogo because it causes the Rocket to stretch and compress like a Pogo stick. First recognized with the Titan II in 1962, Pogo remains a prime consideration in design of launch vehicles today

Urquhart, Skip↗
NASA NTRS1963

THE ELECTRON-BOMBARDMENT ION ROCKET

Proposed electron bombardment ion rocket, discussing ion chamber, magnetic field, cathode, accelerator and neutralizer in terms of spacecraft power requirements

PROPULSION CONFIGURATION↗