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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 307 records · Page 17

An aerodynamic analysis computer program and design notes for low speed wing flap systems

The expanded capabilities for analysis and design of low speed flap systems afforded by recent modifications of an existing computer program is described. The program provides for the simultaneous analysis of up to 25 pairs of leading-edge and trailing-edge flap deflection schedules. Among other new features of the program are a revised attainable thrust estimation method to provide more accurate predictions for low Mach numbers, and a choice of three options for estimation of leading-edge separation vortex flow effects. Comparison of program results with low speed experimental data for an arrow wing supersonic cruise configuration with leading-edge and trailing-edge flaps showed good agreement over most of the range of flap deflections. Other force data comparisons and an independent study of airfoil and wing pressure distributions indicated that wind-tunnel measurements of the aerodynamic performance of twisted and cambered wings and wings with leading-edge flaps can be very sensitive to Reynolds number effects.

Carlson, H. W.↗

Hot-Fire Test Results of an Oxygen/RP-2 Multi-Element Oxidizer-Rich Staged-Combustion Integrated Test Article

As part of the Combustion Stability Tool Development project funded by the Air Force Space and Missile Systems Center, the NASA Marshall Space Flight Center was contracted to assemble and hot-fire test a multi-element integrated test article demonstrating combustion characteristics of an oxygen/hydrocarbon propellant oxidizer-rich staged-combustion engine thrust chamber. Such a test article simulates flow through the main injectors of oxygen/kerosene oxidizer-rich staged combustion engines such as the Russian RD-180 or NK-33 engines, or future U.S.-built engine systems such as the Aerojet-Rocketdyne AR-1 engine or the Hydrocarbon Boost program demonstration engine. For the thrust chamber assembly of the test article, several configurations of new main injectors, using relatively conventional gas-centered swirl coaxial injector elements, were designed and fabricated. The design and fabrication of these main injectors are described in a companion paper at this JANNAF meeting. New ablative combustion chambers were fabricated based on hardware previously used at NASA for testing at similar size and pressure. An existing oxygen/RP-1 oxidizer-rich subscale preburner injector from a previous NASA-funded program, along with existing and new inter-connecting hot gas duct hardware, were used to supply the oxidizer-rich combustion products to the oxidizer circuit of the main injector of the thrust chamber. Results from independent hot-fire tests of the preburner injector in a combustion chamber with a sonic throat are described in companion papers at this JANNAF conference. The resulting integrated test article - which includes the preburner, inter-connecting hot gas duct, main injector, and ablative combustion chamber - was assembled at Test Stand 116 at the East Test Area of the NASA Marshall Space Flight Center. The test article was well instrumented with static and dynamic pressure, temperature, and acceleration sensors to allow the collected data to be used for combustion analysis model development. Hot-fire testing was conducted with main combustion chamber pressures ranging from 1400 to 2100 psia, and main combustion chamber mixture ratios ranging from 2.4 to 2.9. Different levels of fuel film cooling injected from the injector face were examined ranging from none to about 12% of the total fuel flow. This paper presents the hot-fire test results of the integrated test article. Combustion performance, stability, thermal, and compatibility characteristics of both the preburner and the thrust chamber are described. Another companion paper at this JANNAF meeting includes additional and more detailed test data regarding the combustion dynamics and stability characteristics.

Hulka, J. R.↗

Rocket thrust chamber thermal barrier coatings

A research program was conducted to generate data and develop analytical techniques to predict the performance and reliability of ceramic thermal barrier coatings in high heat flux environments. A finite element model was used to analyze the thermomechanical behavior of coating systems in rocket thrust chambers. Candidate coating systems (using a copper substrate, NiCrAlY bond coat and ZrO2.8Y2O3 ceramic overcoat) were selected for detailed study based on photomicrographic evaluations of experimental test specimens. The effects of plasma spray application parameters on the material properties of these coatings were measured and the effects on coating performance evaluated using the finite element model. Coating design curves which define acceptable operating envelopes for seleted coating systems were constructed based on temperature and strain limitations. Spray gun power levels was found to have the most significant effect on coating structure. Three coating systems were selected for study using different power levels. Thermal conductivity, strain tolerance, density, and residual stress were measured for these coatings. Analyses indicated that extremely thin coatings ( 0.02 mm) are required to accommodate the high heat flux of a rocket thrust chamber and ensure structural integrity.

Batakis, A. P.↗

Modeling of thruster and solar array characteristics in the JPL low-thrust trajectory analysis

Recent advances in thruster and solar array technology have resulted in the possibility of performing many high energy space missions previously considered infeasible. This capability was demonstrated by an extensive study last year of a comet Halley rendezvous mission. In order to perform this extremely high energy mission, several advanced concepts in electric propulsion technology were investigated; notably the use of very high power, lightweight solar arrays which directly powered the beam supply of the electric propulsion thrusters, and the use of solar concentrators on the arrays together with conventional thrusters and power processors. These technology advances have directly impacted the modeling of the solar arrays and thrusters in the programs used in generating low-thrust trajectories. The intent of this paper is to discuss the modeling of the solar arrays and thrusters as employed in the trajectory programs presently being used in low-thrust mission studies at JPL.

Sauer, C. G., Jr.↗

The Pathfinder Chemical Transfer Propulsion program

Pathfinder is a research and technology initiative by the National Aeronautics and Space Administration (NASA) intended to strengthen the technology base of the United States civil space program in preparation for future space exploration missions. Pathfinder begins in FY-89. One of the four major thrusts of Pathfinder is Space Transfer technology. A key element of this thrust is the Chemical Transfer Propulsion program which will provide the propulsion technology for high performance, liquid oxygen/liquid hydrogen expander cycle engines which are expected to be operated and maintained in space. These advanced engines will enhance or enable a variety of future space exploration missions. This paper describes the goals and objectives, management, technical plan, and technology transfer for the Chemical Transfer Propulsion element of Pathfinder.

Hannum, Ned P.↗

The Pathfinder Chemical Transfer Propulsion Program

Pathfinder is a research and technology initiative by the National Aeronautics and Space Administration (NASA) intended to strengthen the technology base of the United States civil space program in preparation for future space exploration missions. Pathfinder begins in FY-89. One of the four major thrusts is the Chemical Transfer Propulsion program which will provide the propulsion technology for high performance, liquid oxygen/liquid hydrogen expander cycle engines which are expected to be operated and maintained in space. These advanced engines will enhance or enable a variety of future space exploration missions. The goals and objectives, management, technical plan, and technology transfer for the Chemical Transfer Propulsion element of Pathfinder are described.

Hannum, Ned P.↗

AIST Overview Advanced Information System Technology Fueling Innovation for Earth Observing

One element of NASA's Earth Science Technology Office is the Advanced Information Systems Technology (AIST) Program, which funds information technology development for use in the 5-20 year timeframe. The needs are identified in conjunction with the NASA research and applied sciences communities and discussions with other, forward-looking organizations, such as ESA. AIST projects must have a US lead, but collaborations with non-US organizations are encouraged. The AIST Program focuses on two major thrusts and a small collection of concept studies and solicits both evolutionary and disruptive development projects. One thrust seeks to leverage the emergence of smallsats to create constellations of instruments to examine phenomena that could not be studied before using conventional single-satellite instruments. The second thrust develops re-usable tools to support scientific investigations through the interaction with data. The study projects formulate relevant theory, bleeding-edge concepts or to articulate need statements more clearly for highly advanced work. This talk will describe the research and development funded by the AIST Program.

Little, Michael M.↗

Cooling of high pressure rocket thrust chambers with liquid oxygen

An experimental program using hydrogen and oxygen as the propellants and supercritical liquid oxygen (LOX) as the coolant was conducted at 4.14 and 8.274 MN/sq m chamber pressure. It was aimed to demonstrate the effect of LOX leaking into the combustion region through small cracks in the chamber wall, and to verify the supercritical oxygen heat transfer correlation developed from heated tube experiments. Four thrust chambers with throat diameters of 0.066 m were tested; three of these were cyclically tested to 4.14 MM/sq m chamber pressure until a crack developed; the fourth chamber was operated at 8.274 MM/sq m pressure to obtain steady state heat transfer data. Wall temperature measurements confirmed the heat transfer correlation.

Price, H. G.↗

New Observing Strategy (NOS) for Future Earth Science Missions

One of the new thrusts of the Earth Science Technology Office (ESTO) Advanced Information Systems Technology (AIST) Program is the New Observing Strategy (NOS) thrust. Its goal is to provide a framework for identifying technology advances needed to exploit newly available observational capabilities, particularly to enable the development of the information technologies needed to support planning, evaluating, implementing, and operating dynamic, multi-element sets of observing assets. In this paper, we will introduce relevant NOS terminology and some key concepts before describing the objectives, driving factors and technology goals of this new thrust.

Advanced Information Systems↗

Air Force electrochemical power research and technology program for space applications

An overview is presented of the existing Air Force electrochemical power, battery, and fuel cell programs for space application. Present thrusts are described along with anticipated technology availability dates. Critical problems to be solved before system applications occur are highlighted. Areas of needed performance improvement of batteries and fuel cells presently used are outlined including target dates for key demonstrations of advanced technology. Anticipated performance and current schedules for present technology programs are reviewed. Programs that support conventional military satellite power systems and special high power applications are reviewed. Battery types include bipolar lead-acid, nickel-cadmium, silver-zinc, nickel-hydrogen, sodium-sulfur, and some candidate advanced couples. Fuel cells for pulsed and transportation power applications are discussed as are some candidate advanced regenerative concepts.

Allen, Douglas↗

Operating manual for coaxial injection combustion model

An operating manual for the coaxial injection combustion model (CICM) is presented as the final report for an eleven month effort designed to provide improvement, to verify, and to document the comprehensive computer program for analyzing the performance of thrust chamber operation with gas/liquid coaxial jet injection. The effort culminated in delivery of an operation FORTRAN IV computer program and associated documentation pertaining to the combustion conditions in the space shuttle main engine. The computer program is structured for compatibility with the standardized Joint Army-Navy-NASA-Air Force (JANNAF) performance evaluation procedure. Use of the CICM in conjunction with the JANNAF procedure allows the analysis of engine systems using coaxial gas/liquid injection.

Sutton, R. D.↗

US computer research networks: Current and future

During the last decade, NASA LeRC's Communication Program has conducted a series of telecommunications forecasting studies to project trends and requirements and to identify critical telecommunications technologies that must be developed to meet future requirements. The Government Networks Division of Contel Federal Systems has assisted NASA in these studies, and the current study builds upon these earlier efforts. The current major thrust of the NASA Communications Program is aimed at developing the high risk, advanced, communications satellite and terminal technologies required to significantly increase the capacity of future communications systems. Also, major new technological, economic, and social-political events and trends are now shaping the communications industry of the future. Therefore, a re-examination of future telecommunications needs and requirements is necessary to enable NASA to make management decisions in its Communications Program and to ensure the proper technologies and systems are addressed. This study, through a series of Task Orders, is helping NASA define the likely communication service needs and requirements of the future and thereby ensuring that the most appropriate technology developments are pursued.

Kratochvil, D.↗

Cooling of High Pressure Rocket Thrust Chambers with Liquid Oxygen

An experimental program using hydrogen and oxygen as the propellants and supercritical liquid oxygen (LOX) as the coolant was conducted at 4.14 and 8.274 MN/square meters (600 and 1200 psia) chamber pressure. Data on the following are presented: the effect of LOX leaking into the combustion region through small cracks in the chamber wall; and verification of the supercritical oxygen heat transfer correlation developed from heated tube experiments; A total of four thrust chambers with throat diameters of 0.066 m were tested. Of these, three were cyclically tested to 4.14 MN/square meters (600 psia) chamber pressure until a crack developed. One had 23 additional hot cycles accumulated with no apparent metal burning or distress. The fourth chamber was operated at 8.274 MN/square meters (1200 psia) pressure to obtain steady state heat transfer data. Wall temperature measurements confirmed the heat transfer correlation.

Price, H. G.↗

Experimental investigation of combustor effects on rocket thrust chamber performance

A design and experimental program to develop special instrumentation systems, design engine hardware, and conduct tests using LOX/GH2 propellants in which the propellant flow stratification was controlled is described. The mixture ratio was varied from 4.6 to 6 overall. The mixture ratios in the core and outer zone were varied from 3.5 to 6 and 5 to 8, respectively. The range in boundary layer coolant was from 0 to 10 percent of the fuel. The nominal chamber pressure and thrust were 225 psia and 7000 pounds, respectively. Pressure and heat flux profiles as well as gas sampling of the exhaust products were obtained. Specific impulse efficiencies of approximately 94 percent and characteristic velocity efficiencies of approximately 97 percent were obtained during the experiments.

Source record↗

Thrust and mass flow characteristics of four 36 inch diameter tip turbine fan thrust vectoring systems in and out of ground effect

The calibration tests carried out on the propulsion system components of a 70 percent scale, powered model of a NASA 3-fan V/STOL aircraft configuration are described. The three X3/6B/T58 turbotip fan units used in the large scale powered model were tested on an isolated basis over a range of ground heights from H/D of 1.02 to infinity. A higher pressure ratio LF336/J85 fan unit was tested over a range of ground heights from 1.55 to infinity. The results of the test program demonstrated that: (1) the thrust and mass flow performance of the X376B/T58 nose lift unit is essentially constant for H/D variations down to 1.55; at H/D 1.02 back pressurization of the fan exit occurs and is accompanied by an increase in thrust of five percent; (2) a change in nose fan exit hub shape from flat plate to hemispherical produces no significant difference in louvered lift nozzle performance for height variations from H/D = 1.02 to infinity; (3) operation of the nose lift nozzle at the higher fan pressure ratio generated by the LF336/J85 fan system causes no significant change in ground proximity performance down to an H/D of 1.55, the lowest height tested with this unit; and (4) the performance of the left and right X376B/T58 lift/cruise units in the vertical lift mode remains unchanged, within plus or minus two percent for the range of ground heights from H/D = 1.02 to infinity.

Esker, D. W.↗

Georgia Institute of Technology research on the Gas Core Actinide Transmutation Reactor (GCATR)

The program reviewed is a study of the feasibility, design, and optimization of the GCATR. The program is designed to take advantage of initial results and to continue work carried out on the Gas Core Breeder Reactor. The program complements NASA's program of developing UF6 fueled cavity reactors for power, nuclear pumped lasers, and other advanced technology applications. The program comprises: (1) General Studies--Parametric survey calculations performed to examine the effects of reactor spectrum and flux level on the actinide transmutation for GCATR conditions. The sensitivity of the results to neutron cross sections are to be assessed. Specifically, the parametric calculations of the actinide transmutation are to include the mass, isotope composition, fission and capture rates, reactivity effects, and neutron activity of recycled actinides. (2) GCATR Design Studies--This task is a major thrust of the proposed research program. Several subtasks are considered: optimization criteria studies of the blanket and fuel reprocessing, the actinide insertion and recirculation system, and the system integration. A brief review of the background of the GCATR and ongoing research is presented.

Clement, J. D.↗

International Space Weather Initiative (ISWI)

The International Heliophysical Year (IHY), an international program of scientific collaboration to understand the external drivers of planetary environments, has come to an end. The IHY was a major international event of great interest to the member States, which involved the deployment of new instrumentation, new observations from the ground and in space, and an education component. We propose to continue the highly successful collaboration between the heliophysics science community and the United Nations Basic Space Science (UNBSS) program. One of the major thrust of the IHY was to deploy arrays of small instruments such as magnetometers, radio antennas, GPS receivers, all-sky cameras, particle detectors, etc. around the world to provide global measurements of heliospheric phenomena. The United Nations Basic Space Science Initiative (UNBSSI) played a major role in this effort. Scientific teams were organized through UNBSS, which consisted of a lead scientist who provided the instruments or fabrication plans for instruments in the array. As a result of the this program, scientists from UNBSS member states now participate in the instrument operation, data collection, analysis, and publication of scientific results, working at the forefront of science research. As part of this project, support for local scientists, facilities and data acquisition is provided by the host nation. In addition, support at the Government level is provided for local scientists to participate. Building on momentum of the IHY, we propose to continue the highly successful collaboration with the UNBSS program to continue the study of universal processes in the solar system that affect the interplanetary and terrestrial environments, and to continue to coordinate the deployment and operation of new and existing instrument arrays aimed at understanding the impacts of Space Weather on Earth and the near-Earth environment. Toward this end, we propose a new program, the International Space Weather Initiative (ISWI).

Davila, Joseph M.↗