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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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Report contains results of performance tests on complete system for solar space and hot-water heating system that uses commercially available components. Results were used to determine system suitability for field installation and to generate performance data base for comparison with future tests on field installed systems.
Portable spray booth provides for controlled application of coating materials with high solvent contents. Includes contoured shroud and carbon filter bed limiting concentration of fumes in vicinity. Designed to substitute spraying for brush application of solvent-based adhesive prior to installing rubber waterproof seals over joints between segments of solid-fuel rocket motor. With minor adjustments and modifications, used to apply other solvent-based adhesives, paints, and like.
Laser vapor screen (LVS) flow visualization systems that are fiber-optic based were developed and installed for aerodynamic research in the Langley 8-Foot Transonic Pressure Tunnel and the Langley 7- by 10-Foot High Speed Tunnel. Fiber optics are used to deliver the laser beam through the plenum shell that surrounds the test section of each facility and to the light-sheet-generating optics positioned in the ceiling window of the test section. Water is injected into the wind tunnel diffuser section to increase the relative humidity and promote condensation of the water vapor in the flow field about the model. The condensed water vapor is then illuminated with an intense sheet of laser light to reveal features of the flow field. The plenum shells are optically sealed; therefore, video-based systems are used to observe and document the flow field. Operational experience shows that the fiber-optic-based systems provide safe, reliable, and high-quality off-surface flow visualization in smaller and larger scale subsonic and transonic wind tunnels. The design, the installation, and the application of the Langley Research Center (LaRC) LVS flow visualization systems in larger scale wind tunnels are highlighted. The efficiency of the fiber optic LVS systems and their insensitivity to wind tunnel vibration, the tunnel operating temperature and pressure variations, and the airborne contaminants are discussed.
An optimization capability is developed for acoustic scattering and shielding of installed propellers and rotors, based on a spacetime Galerkin time domain boundary element method (TDBEM). The time domain approach is particularly suitable for efficient simulation of transient, rotating, and broadband noise sources such as propellers. The use of algorithmic differentiation allows efficient evaluation of design sensitivities required for gradient-based design optimization with a large number of design variables. We present a validation exercise for the coherent broadband scattering capability against an analytical solution, showing excellent agreement. We then demonstrate the optimization tool on a series of inverse design cases with broadband and rotating sources, as well as an optimization problem for a propeller-wing configuration. The results show good performance for optimization problems with the characteristics of realistic installed propeller configurations.
An optimization capability is developed for acoustic scattering and shielding of installed propellers and rotors, based on a spacetime Galerkin time domain boundary element method (TDBEM). The time domain approach is particularly suitable for efficient simulation of transient, rotating, and broadband noise sources such as propellers. The use of algorithmic differentiation allows efficient evaluation of design sensitivities required for gradient-based design optimization with a large number of design variables. We present a validation exercise for the coherent broadband scattering capability against an analytical solution, showing excellent agreement. We then demonstrate the optimization tool on a series of inverse design cases with broadband and rotating sources, as well as an optimization problem for a propeller-wing configuration. The results show good performance for optimization problems with the characteristics of realistic installed propeller configurations.
The objective of this project is to expand the capabilities of for the Mars Umbilical Technology Demonstrator (MUTD). The MUTD shall provide electrical power and fiber optic data cable connections between two simulated mars vehicles, 1000 in apart. ne wheeled mobile robot Omnibot is used to provide the mobile base for the system. The mate-to umbilical plate is mounted on a Cartesian robot, which is installed on the Omnibot mobile base. It is desirable to provide the operator controlling the Omnibot, the distance and direction to the target. In this report, an approach for finding the position and orientation of the mobile robot using inertial sensors and beacons is investigated. First phase of the project considered the Omnibot being on the flat surface. To deal with the uneven Mars environment, the orientation as well as position needs to be controlled. During local positioning, the information received from four ultrasonic sensors installed at the four corner of the mate-mi plate is used to identify the position of mate-to plate and mate the umbilical plates autonomously. The work proposed is the continuation of the principal investigator research effort as a participant in the 1999 NASA/ASEE Summer Faculty Fellowship Program.
The Propulsion Systems Branch at NASA s Lyndon B. Johnson Space Center (JSC) has developed a parametric analytical tool to address the need to rapidly predict heat leak into propellant distribution lines based on insulation type, installation technique, line supports, penetrations, and instrumentation. The Propellant Feed System Analytical Tool (PFSAT) will also determine the optimum orifice diameter for an optional thermodynamic vent system (TVS) to counteract heat leak into the feed line and ensure temperature constraints at the end of the feed line are met. PFSAT was developed primarily using Fortran 90 code because of its number crunching power and the capability to directly access real fluid property subroutines in the Reference Fluid Thermodynamic and Transport Properties (REFPROP) Database developed by NIST. A Microsoft Excel front end user interface was implemented to provide convenient portability of PFSAT among a wide variety of potential users and its ability to utilize a user-friendly graphical user interface (GUI) developed in Visual Basic for Applications (VBA). The focus of PFSAT is on-orbit reaction control systems and orbital maneuvering systems, but it may be used to predict heat leak into ground-based transfer lines as well. PFSAT is expected to be used for rapid initial design of cryogenic propellant distribution lines and thermodynamic vent systems. Once validated, PFSAT will support concept trades for a variety of cryogenic fluid transfer systems on spacecraft, including planetary landers, transfer vehicles, and propellant depots, as well as surface-based transfer systems. The details of the development of PFSAT, its user interface, and the program structure will be presented.
The objective of this project is to develop a autonomous umbilical mating for the mars umbilical technology demonstrator. The Mars Umbilical Technology Demonstrator (MUTD) shall provide electrical power and fiber optic data cable connections between two simulated mars vehicles. The Omnibot is used to provide the mobile base for the system. The mate to umbilical plate is mounted on a three axis Cartesian table, which is installed on the Omnibot mobile base. The Omnibot is controlled in a teleoperated mode. The operator using the vision system will guide the Omnibot to get close to the mate to plate. The information received from four ultrasonic sensors is used to identify the position of mate to plate and mate the umbilical plates autonomously. A successful experimentation verifies the approach.
STS-111 Mission Specialist 2 Franklin Chang-Diaz is seen during this interview, where he gives a quick overview of the mission before answering questions about his inspiration to become an astronaut and his career path. Chang-Diaz outlines his role in the mission in general, and specifically during the extravehicular activities (EVAs). He describes in great detail his duties in the three EVAs which involved preparing the Mobile Remote Servicer Base System (MBS) for installation onto the Space Station's Mobile Transporter, attaching the MBS onto the Space Station and replacing a wrist roll joint on the station's robot arm. Chang-Diaz also discusses the science experiments which are being brought on board the Space Station by the STS-111 mission. He also offers thoughts on how the International Space Station (ISS) fits into NASA's vision and how his previous space mission experience will benefit the STS-111 flight.
One of NASA's long term goals continues to be the exploration of other planets and orbital bodies in our solar system. Our sustained presence through the installation of stations or bases on these planetary surfaces will depend on developing properly designed habitation modules, mobility systems and supporting infrastructure. NASA Glenn Research Center is involved in several technology developments in support of this overarching goal. Two key developments are in the area of advanced filtration and excavation systems. The first addresses the issues posed by the accumulation of particulate matter over long duration missions and the intrusion of planetary dust into spacecraft and habitat pressurized cabins. The latter supports the operation and infrastructure of insitu resource utilization (ISRU) processes to derive consumables and construction materials from the planetary regolith. These two developments require a basic understanding of the lunar regolith at the micro (particle) to macro (bulk) level. Investigation of the relevant properties of the lunar regolith and characterization of the standard simulant materials used in. testing were important first steps in these developments. The fundamentals and operational concepts of these technologies as well as descriptions of new NASA facilities, including the Particulate Filtration Testing and the NASA Excavation and Traction Testing facilities, and their capabilities for testing and advancing these technologies will be presented. The test data also serves to validate and anchor computational simulation models.
Measurement of the jet thrust of a turbojet engine in flight becomes more difficult as the number and complexity of the engine components increase. It is desirable, therefore, that a general correlation of jet thrust be developed which is applicable to a simple direct reading thrustmeter. In view of this need a correlation is presented which is independent of flight conditions and applicable to both non-afterburning and afterburning engines equipped with nonejector type fixed- and variable-area convergent exhaust nozzles. The general equation used in this correlation was derived from the theoretical jet-thrust equation for a choked convergent nozzle. The data used to verify the correlation were obtained over a range of altitudes from 10,000 to 54,000 feet and a range of flight Mach numbers from 0.4 to 1.1. A thrustometer based on this equation was installed on an afterburning turbojet engine equipped with a fixed area convergent exhaust nozzle. The results indicated that a meter based on this correlation would be applicable to a flight installation and that the probable error in thrust measurement would be approximately + or -1.5 percent provided the exhaust-nozzle thrust coefficient is known.
Simple tool based on principle of automobile oil wrench slips over cylindrical thread-on baffle to install or remove it from baffle assembly. Tool consists of curled metal sheet brazed onto handgrip. Handgrip is adapted to be driven by wrench, ratchet, extension, torque wrench, or some other convenient tool. Clockwise twist of handgrip, tightens metal sheet around baffle to advance it into threaded joint. Counterclockwise twist loosens sheet for repositioning or tool removal.
Sergei Treschev is a Cosmonaut of the Rocket Space Corporation Energia, (RSC), from Volynsky District, Lipetsk Region (Russia). He graduated from Moscow Energy Institute. After years of intense training with RSC Energia, he was selected as International Space Station (ISS) Increment 5 flight engineer. The Expedition-Five crew (two Russian cosmonauts and one American astronaut) will stay on the station for approximately 5 months. The Multipurpose Logistics Module, or MPLM, will carry experiment racks and three stowage and resupply racks to the station. The mission will also install a component of the Canadian Arm called the Mobile Base System (MBS) to the Mobile Transporter (MT) installed during STS-110. This completes the Canadian Mobile Servicing System, or MSS. The mechanical arm will now have the capability to "inchworm" from the U.S. Lab fixture to the MSS and travel along the Truss to work sites.
The Moon is an excellent site for astronomical observations. This paper describes two geological aspects related to astronomy from the Moon. First it evaluates the sources of gases near a lunar base as input to calculations reported in a separate paper on the growth of an artificial lunar atmosphere. The results suggest that mining for He-3 could produce the most gas (1 kg/sec), but rocket exhaust (0.1 kg/sec) and habitat venting (0.5 kg/sec) are also important. Second, the paper discusses criteria that need to be considered when determining the site of a lunar astronomical facility. These are longitude and latitude (equatorial sites are favored), topography (important to be relatively flat for ease of installation), distance from a lunar base (to be free of seismic noise, dust, and gases), the site's value to lunar geoscience (other factors being equal, a geologically diverse site is better), and its value as a materials resource (mining and observatories are incompatible).
A computational heat transfer methodology was developed to study the dual-engine linear aerospike plume induced base-heating environment during one power-pack out, in ascent flight. One power-pack out results in reduction of power levels for both engines. That, in turn, reduces the amount of base-bleed and changes the distribution of base-bleed on the two pillows. Hence, the concern of increased base-heating during power-pack out. The thermo-flowfield of the entire vehicle was computed. The computational methodology for the convective heating is based on a three-dimensional, finite-volume, viscous, chemically reacting, and pressure-based computational fluid dynamics formulation. The computational methodology for the radiative heating is based on a three-dimensional, finite-volume, and spectral-line-based weighted-sum-of-gray-gases absorption computational radiation heat transfer formulation. A separate radiation model was used for diagnostic purposes. The computational methodology was systematically benchmarked. In this study, near-base radiative heat fluxes were computed and they compared well with those measured from an installed linear aerospike engine tests. The base-heating environment of 18 trajectory points selected from three power-pack out ascent scenarios was computed and is presented here. The power-pack out condition has the most impact on convective base-heating when it happens early in flight. The some of its impact comes from the asymmetric and reduced base-bleed.
The economic analysis of the solar energy system that was installed at Akron, Ohio is developed for this and four other sites typical of a wide range of environmental and economic conditions. The analysis is accomplished based on the technical and economic models in the f chart design procedure with inputs based on the characteristics of the installed parameters of present worth of system cost over a projected twenty year life: life cycle savings, year of positive savings and year of payback for the optimized solar energy system at each of the analysis sites. The sensitivity of the economic evaluation to uncertainties in constituent system and economic variables is also investigated. Results show that only in Albuquerque, New Mexico, where insolation is 1828 Btu/sq ft/day and the conventional energy cost is high, is this solar energy system marginally profitable.
Published and unpublished information relating to encapsulation systems and materials properties was collected by searching the literature and appropriate data bases (over 1,300 documents were selected and reviewed) and by personal contacts including site and company visits. A data tabulation summarizing world experience with terrestrial photovoltaic arrays (50 installations) is presented in the report. Based on criteria of properties, processability, availability, and cost, candidate materials were identified which have potential for use in encapsulation systems for arrays with a lifetime of over 20 years high reliability, an efficiency greater than 10 percent, a total price less than $500/kW, and a production capacity of 500,000 kW/yr. The recommended materials (all commercially available) include, depending upon the device design, various borosilicate and soda-lime glasses and numerous polymerics suitable for specific encapsulation system functions.
Reporting technique and method of sequencing operations based on parts availability and installation