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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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Design data are presented for the graphical construction of two-dimensional sharp-edge-throat supersonic nozzles of minimum length for test-section Mach numbers from 1.20 to 10.00. The method of characteristics used in the design is briefly reviewed.
A method of interference is described in the present report which promises profitable application in aeronautical research. The physical foundation of the method and a simple method of adjustment are briefly discussed. The special technical construction of the instrument is described which guarantees its use also in the case of vibrations of the surrounding space and permits the investigation of unsteady phenomena. It is found that the interference method will make the small differences in density in the flow field around the body even at low speeds. (40 m/sec) optically measurable.
The design and initial construction of a mobile regenerative power system is described. The main components of the power system consists of a photovoltaic array, regenerative fuel cell and electrolyzer. The system is mounted on a modified landscape trailer and is completely self contained. An operational analysis is also presented that shows predicted performance for the system at various times of the year. The operational analysis consists of performing an energy balance on the system based on array output and total desired operational time.
Within NASA's Aviation Safety Program, NASA GRC participates in the Modeling and Simulation Project called ASMM. NASA GRC s focus is to characterize the propulsion systems performance from a fleet management and maintenance perspective by modeling and through simulation predict the characteristics of two classes of commercial engines (CFM56 and GE90). In prior years, the High Performance Computing and Communication (HPCC) program funded, NASA Glenn in developing a large scale, detailed simulations for the analysis and design of aircraft engines called the Numerical Propulsion System Simulation (NPSS). Three major aspects of this modeling included the integration of different engine components, coupling of multiple disciplines, and engine component zooming at appropriate level fidelity, require relatively tight coupling of different analysis codes. Most of these codes in aerodynamics and solid mechanics are written in Fortran. Refitting these legacy Fortran codes with distributed objects can increase these codes reusability. Aviation Safety s modeling and simulation use in characterizing fleet management has similar needs. The modeling and simulation of these propulsion systems use existing Fortran and C codes that are instrumental in determining the performance of the fleet. The research centers on building a CORBA-based development environment for programmers to easily wrap and couple legacy Fortran codes. This environment consists of a C++ wrapper library to hide the details of CORBA and an efficient remote variable scheme to facilitate data exchange between the client and the server model. Additionally, a Web Service model should also be constructed for evaluation of this technology s use over the next two- three years.
Software was developed to construct approximating NURBS curves for iced airfoil geometries. Users specify a tolerance that determines the extent to which the approximating curve follows the rough ice. The user can therefore smooth the ice geometry in a controlled manner, thereby enabling the generation of grids suitable for numerical aerodynamic simulations. Ultimately, this ability to smooth the ice geometry will permit studies of the effects of smoothing upon the aerodynamics of iced airfoils. The software was applied to several different types of iced airfoil data collected in the Icing Research Tunnel at NASA Glenn Research Center, and in all cases was found to efficiently generate suitable approximating NURBS curves. This method is an improvement over the current "control point formulation" of Smaggice (v.1.2). In this report, we present the relevant theory of approximating NURBS curves and discuss typical results of the software.
Through a prototype implementation (Tian et al., this meeting) the VSO has already demonstrated the capability of unifying geographically distributed data sources following the Web Services paradigm and utilizing mechanisms such as the Simple Object Access Protocol (SOAP). So far, four participating sites (Stanford, Montana State University, National Solar Observatory and the Solar Data Analysis Center) permit Web-accessible, time-based searches that allow browse access to a number of diverse data sets. Our latest work includes the extension of the simple, time-based queries to include numerous other searchable observation parameters. For VSO users, this extended functionality enables more refined searches. For the VSO, it is a proof of concept that more complex, distributed queries can be effectively constructed and that results from heterogeneous, remote sources can be synthesized and presented to users as a single, virtual data product.
One way of studying the risk to human health of low-level radiation exposure is to make biological experiments on living cell cultures. Two 210Po alpha-particle emitting devices, with 0.5 and 100 MBq activity, were designed and constructed to perform such experiments irradiating monolayers of cells. Estimates of dose rate at the cell surface were obtained from measurements by a PIPS alpha-particle spectrometer and from calculations by the SRIM 2000, Monte Carlo charged particle transport code. Particle fluence area distributions were measured by solid state nuclear track detectors. The design and dosimetric characterisation of the devices are discussed. c2002 Elsevier Science Ltd. All rights reserved.
The focus of my work this summer was fire safety, specifically determining fire signatures from the combustion of materials commonly found in the construction of spacecraft. This project was undertaken with the aim of addressing concerns for health and safety onboard spacecraft. Under certain conditions, burning electronics produce surprisingly large amounts of acrid smoke, release fine airborne particles and expel condensable aerosols. Similarly, some wire insulation and packing material evolves smoke when in contact with a hot surface. In the limited, enclosed space available on spacecraft, these combustion products may pose a nuisance at the very least - at worst, a hazard to health or equipment. There is also a concern for fire safety in early detection on spacecraft. Our goal for the summer was to determine the most effective methods to test the materials, develop a protocol for sampling, and generate samples for analysis. We restricted our testing to electronic components, packaging and insulation materials, and wire insulation materials.
A methodology is developed and implemented to mitigate the lengthy software development cycle typically associated with constructing a discrete adjoint solver for aerodynamic simulations. The approach is based on a complex-variable formulation that enables straightforward differentiation of complicated real-valued functions. An automated scripting process is used to create the complex-variable form of the set of discrete equations. An efficient method for assembling the residual and cost function linearizations is developed. The accuracy of the implementation is verified through comparisons with a discrete direct method as well as a previously developed handcoded discrete adjoint approach. Comparisons are also shown for a large-scale configuration to establish the computational efficiency of the present scheme. To ultimately demonstrate the power of the approach, the implementation is extended to high temperature gas flows in chemical nonequilibrium. Finally, several fruitful research and development avenues enabled by the current work are suggested.
The NASA Langley Research Center Low Speed Aeroacoustic Wind Tunnel is a premier facility for model-scale testing of jet noise reduction concepts at realistic flow conditions. However, flow inside the open jet test section is less than optimum. A Construction of Facilities project, scheduled for FY 05, will replace the flow collector with a new design intended to reduce recirculation in the open jet test section. The reduction of recirculation will reduce background noise levels measured by a microphone array impinged by the recirculation flow and will improve flow characteristics in the open jet tunnel flow. In order to assess the degree to which this modification is successful, background noise levels and tunnel flow are documented, in order to establish a baseline, in this report.
The Aviation Environmental Technical Branch produces many various types of aeronautical research that benefits the NASA mission for space exploration and in turn, produces new technology for our nation. One of the present goals of the Aviation Environmental Technical Branch is to create better engines for airplanes by testing supersonic jet propulsion and safe fuel combustion. During the summer of 2004, I was hired by Vincent Sattenvhite Chief executive of the Aviation Environmental Technical Branch to Assist Yves Lamothe with a fuel igniter circuit. Yves Lamothe is an electrical engineer who is currently working on safe fuel combustion testing. This testing is planned to determine the minimum ignition energy for fuel and air vapors of current and alternative fuels under simulated flight conditions. An air temperature bath will provide simulated flight profile temperatures and the heat fluxes to the test chamber. I was assigned with Yves to help complete the igniter circuit which consists of a 36k voltage supply an oscilloscope, and a high voltage transistor switch. During my tenure in the L.E.C.I.R.P. program I studied the basics of electricity and circuitry along with two other projects that I completed. In the beginning of my internship, I devote all of my time to research the aspects of circuitry so that I would be prepared for the projects that I was assigned to do. I read about lessons on; the basic physical concepts of electronics, Electrical units, Basic dc circuits, direct current circuit analysis, resistance and cell batteries, various types of magnetism , Alternating current basics, inductance, and power supplies. I received work sheets and math equations from my Mentor so that I could be able to apply these concepts into my work. After I complete my studies, I went on to construct a LED chaser circuit which displays a series of light patterns using a 555 timer. I incorporated a switch and motion detector into the circuit to create basic alarm system. This project challenged my ability to interpret a schematic and expand it. While I was still completing the LED chaser circuit I Also was given A Basic Stamp Toddler Robot to build and program. The Toddler robot can walk in 36 various styles using advanced robotics. I used many different programs to create movement and direction of the robot. Also the Toddler can use infrared vision to sense objects. This enables the robot to maneuver indefinitely without running into objects. During my tenure at the NASA Glen Research Center I definite utilized the NASA mission to educate. I learned valuable information to help in my up coming year as a freshman in college.
Over the last year, the Glenn Research Center's Icing Research Tunnel (IRT) underwent a major $5.2 million rehabilitation project as part of the Construction of Facilities program. The scope of the project included redesign and replacement of the 55-yr-old heat exchanger, the addition of fan outlet guide vanes for flow conditioning downstream of the 25-ft-diameter fan, and redesign and replacement of the C and D corner-turning vanes. The purpose of the rehabilitation was to replace old portions of the infrastructure and to improve the aerodynamic flow quality in the tunnel.
An electrostatic shielding concept for spacecraft radiation protection under NASA s Exploration Systems Research and Technology Program was evaluated for its effectiveness and feasibility. The proposed shield design is reminiscent of a classic quadrupole with positively and negatively charged spheres surrounding the spacecraft. The project addressed materials, shield configuration, power supply, and compared its effectiveness to that of a passive shield. The report herein concerns the identification of commercially available materials that could be used in sphere fabrication. It was found that several materials were needed to potentially construct the spheres for an electrostatic shield operating at 300 MV.
A series of six-hourly, synoptic, gridded, global surface wind fields with a resolution of 100 km has been generated using the data set of dealiased Seasat satellite scatterometer (SASS) winds produced as described by peteherych et al. (1984). This paper is an account of the construction of surface pressure fields from these SASS synoptic wind fields only, as carried out by differnt methods, and the comparison of these pressure fields with U.S. National Centers for Environmental Prediction (NCEP) analyses, with the pressure fields of the European Center for Medium Range Weather Forecasting (ECMWF) and with the special analyses of the Gulf of Alaska Experiment (GOASEX).
An all-solid-state, high-resolution and frequency-calibrated THz spectrometer based on optical heterodyne in low-temperature-grown (LTG) GaAs been constructed.
Soft-input soft-output building blocks (modules) are presented to construct and iteratively decode in a distributed fashion code networks, a new concept that includes, and generalizes, various forms of concatenated coding schemes.
The Construction and Resource Utilization eXplorer (CRUX) project aims to develop an integrated, flexible suite of instruments with data fusion software and an executive controller for the purpose of in situ resource assessment and characterization for future space exploration.
The Construction and Resource Utilization eXplorer (CRUX) project is developing a flexible integrated suite of instruments with data fusion software and an executive controller for in situ regolith resource assessment and characterization.