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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 487 records · Page 27
All sourcesNASA NTRSDOE OSTI
NASA NTRS2007

Miniature Intelligent Sensor Module

An electronic unit denoted the Miniature Intelligent Sensor Module performs sensor-signal-conditioning functions and local processing of sensor data. The unit includes four channels of analog input/output circuitry, a processor, volatile and nonvolatile memory, and two Ethernet communication ports, all housed in a weathertight enclosure. The unit accepts AC or DC power. The analog inputs provide programmable gain, offset, and filtering as well as shunt calibration and auto-zeroing. Analog outputs include sine, square, and triangular waves having programmable frequencies and amplitudes, as well as programmable amplitude DC. One innovative aspect of the design of this unit is the integration of a relatively powerful processor and large amount of memory along with the sensor-signalconditioning circuitry so that sophisticated computer programs can be used to acquire and analyze sensor data and estimate and track the health of the overall sensor-data-acquisition system of which the unit is a part. The unit includes calibration, zeroing, and signalfeedback circuitry to facilitate health monitoring. The processor is also integrated with programmable logic circuitry in such a manner as to simplify and enhance acquisition of data and generation of analog outputs. A notable unique feature of the unit is a cold-junction compensation circuit in the back shell of a sensor connector. This circuit makes it possible to use Ktype thermocouples without compromising a housing seal. Replicas of this unit may prove useful in industrial and manufacturing settings - especially in such large outdoor facilities as refineries. Two features can be expected to simplify installation: the weathertight housings should make it possible to mount the units near sensors, and the Ethernet communication capability of the units should facilitate establishment of communication connections for the units.

Beech, Russell S.↗
NASA NTRS1990

Potential for integrated optical circuits in advanced aircraft with fiber optic control and monitoring systems

Fiber optic technology is expected to be used in future advanced weapons platforms as well as commercial aerospace applications. Fiber optic waveguides will be used to transmit noise free, high speed data between a multitude of computers as well as audio and video information to the flight crew. Passive optical sensors connected to control computers with optical fiber interconnects will serve both control and monitoring functions. Implementation of fiber optic technology has already begun. Both the military and NASA have several programs in place. A cooperative program, called FOCSI (Fiber Optic Control System Integration), between NASA Lewis and the NAVY to build, environmentally test and flight demonstrate sensor systems for propulsion and flight control systems is currently underway. Integrated Optical Circuits (IOC's) are also being given serious consideration for use in advanced aircraft systems. IOC's will result in miniaturization and localization of components to generate, detect optical signals and process them for use by the control computers. In some complex systems IOC's may be required to perform calculations optically if the technology is ready, replacing some of the electronic systems used today. IOC's are attractive because they will result in rugged components capable of withstanding severe environments in advanced aerospace vehicles. Manufacturing technology developed for microelectronic integrated circuits applied to IOC's will result in cost effective manufacturing. This paper reviews the current FOCSI program and describes the potential role of IOC's in FOCSI applications.

Robert Baumbick↗
NASA NTRS1995

Semi-span model testing in the National Transonic Facility

The objectives of the present research are: (1) to develop a computational approach to support semi-span model test techniques in the NTF; and (2) to integrate this approach with the conduct of an experimental test program. To meet these objectives, the following approach is taken. A state-of-the-art three-dimensional Navier-Stokes solver is employed to compute the flow over both a full-span configuration and a semi-span configuration mounted on the sidewall of the tunnel. The computations are validated by making direct comparisons to experimental data for both configurations. Then, the semi-span computational results are compared to the full-span results to document how the flow over the semi-span configuration differs from that over the full-span configuration. The results of this comparative study will be used to provide a conceptual framework within which a semi-spa model test technique may be implemented in the NTF.

Chokani, Ndaona↗
NASA NTRS1989

Overview of the NASA program in computational structural mechanics

In order to meet the anticipated needs in modeling and analysis of advanced aerospace structures, NASA has developed a program focused on computational structural mechanics. The objective of this program is to advance the state-of-the-art in computational analysis to make accurate analysis of very large and complex structural problems routine. This will be accomplished by emphasizing two key areas: (1) the development of advanced analytical methods, extending beyond traditional approaches and, (2) the exploitation of the newest and most powerful parallel/multiprocessor computers available. Computational testbeds will be developed to serve as technology integrators and to promote/accelerate methodology research and development. An additional, and highly desirable, effect of the Computational Structural Mechanics (CSM) program would be to influence the design of future hardware and software systems to reflect the needs of structural analysis.

Hirschbein, Murray↗
NASA NTRS2000

Space Solar Power Multi-body Dynamics and Controls, Concepts for the Integrated Symmetrical Concentrator Configuration

Orbiting space solar power systems are currently being investigated for possible flight in the time frame of 2015-2020 and later. Such space solar power (SSP) satellites are required to be extremely large in order to make practical the process of collection, conversion to microwave radiation, and reconversion to electrical power at earth stations or at remote locations in space. These large structures are expected to be very flexible presenting unique problems associated with their dynamics and control. The purpose of this project is to apply the expanded TREETOPS multi-body dynamics analysis computer simulation program (with expanded capabilities developed in the previous activity) to investigate the control problems associated with the integrated symmetrical concentrator (ISC) conceptual SSP system. SSP satellites are, as noted, large orbital systems having many bodies (perhaps hundreds) with flexible arrays operating in an orbiting environment where the non-uniform gravitational forces may be the major load producers on the structure so that a high fidelity gravity model is required. The current activity arises from our NRA8-23 SERT proposal. Funding, as a supplemental selection, has been provided by NASA with reduced scope from that originally proposed.

Glaese, John R.↗
NASA NTRS2015

The NASA Electronic Parts and Packaging (NEPP) Program: Overview and the New Tenets for Cost Conscious Mission Assurance on Electrical, Electronic, and Electromechanical (EEE) Parts

The NEPP Program focuses on the reliability aspects of electronic devices (integrated circuits such as a processor in a computer). There are three principal aspects of this reliability: 1) Lifetime, inherent failure and design issues related to the EEE parts technology and packaging; 2) Effects of space radiation and the space environment on these technologies, and; 3) Creation and maintenance of the assurance support infrastructure required for mission success. The NEPP mission is to provide guidance to NASA for the selection and application of microelectronics technologies, to improve understanding of the risks related to the use of these technologies in the space environment, and to ensure that appropriate EEE parts research is performed to meet NASA mission assurance needs. NEPPs FY15 goals are to represent the NASA voice to the greater aerospace EEE parts community including supporting anti-counterfeit and trust, provide relevant guidance to cost-effective missions, aid insertion of advanced (and commercial) technologies, resolve unexpected parts issues, ensure access to appropriate radiation test facilities, and collaborate as widely as possible with external entities. In accordance with the changing mission profiles throughout NASA, the NEPP Program has developed a balanced portfolio of efforts to provide agency-wide assurance for not only traditional spacecraft developments, but also those in-line with the new philosophies emerging worldwide. In this presentation, we shall present an overview of this program and considerations for EEE parts assurance as applied to cost conscious missions.

space radiation↗
NASA NTRS1986

System level verification applying the Space Shuttle experience to the Space Station

The applicability of the verification process for the Shuttle guidance, navigation and control (GNC) and data management system (DMS) for the development of the Space Station are described. Shuttle avionics hardware/software integration was delayed to finalize the hardware design before detailed definition and testing of the software. A block diagram is provided of the flight simulation laboratory used to test the GNC programs before flight data were available. The Station will have distributed computers, unlike the Orbiter, and will only be assembled fully in space. Standardized integration simulation test equipment are being defined to guide the development of hardware and software. The simulation capability may become part of nominal in-flight operations to initiate new capabilities as they are added to the Station. The Station GNC and DMS systems development will be somewhat simplified relative to those of the Shuttle because ascent and reentry will not be considered for the Station.

Gilbert, David W.↗
NASA NTRS1988

Programming model for distributed intelligent systems

A programming model and architecture which was developed for the design and implementation of complex, heterogeneous measurement and control systems is described. The Multigraph Architecture integrates artificial intelligence techniques with conventional software technologies, offers a unified framework for distributed and shared memory based parallel computational models and supports multiple programming paradigms. The system can be implemented on different hardware architectures and can be adapted to strongly different applications.

Sztipanovits, J.↗
NASA NTRS1998

Multidisciplinary Design Technology Development: A Comparative Investigation of Integrated Aerospace Vehicle Design Tools

This research effort is a joint program between the Departments of Aerospace and Mechanical Engineering and the Computer Science and Engineering Department at the University of Notre Dame. Three Principal Investigators; Drs. Renaud, Brockman and Batill directed this effort. During the four and a half year grant period, six Aerospace and Mechanical Engineering Ph.D. students and one Masters student received full or partial support, while four Computer Science and Engineering Ph.D. students and one Masters student were supported. During each of the summers up to four undergraduate students were involved in related research activities. The purpose of the project was to develop a framework and systematic methodology to facilitate the application of Multidisciplinary Design Optimization (N4DO) to a diverse class of system design problems. For all practical aerospace systems, the design of a systems is a complex sequence of events which integrates the activities of a variety of discipline "experts" and their associated "tools". The development, archiving and exchange of information between these individual experts is central to the design task and it is this information which provides the basis for these experts to make coordinated design decisions (i.e., compromises and trade-offs) - resulting in the final product design. Grant efforts focused on developing and evaluating frameworks for effective design coordination within a MDO environment. Central to these research efforts was the concept that the individual discipline "expert", using the most appropriate "tools" available and the most complete description of the system should be empowered to have the greatest impact on the design decisions and final design. This means that the overall process must be highly interactive and efficiently conducted if the resulting design is to be developed in a manner consistent with cost and time requirements. The methods developed as part of this research effort include; extensions to a sensitivity based Concurrent Subspace Optimization (CSSO) MDO algorithm; the development of a neural network response surface based CSSO-MDO algorithm; and the integration of distributed computing and process scheduling into the MDO environment. This report overviews research efforts in each of these focus. A complete bibliography of research produced with support of this grant is attached.

Renaud, John E.↗
NASA NTRS1978

Synthesis of aircraft structures using integrated design and analysis methods

A systematic research is reported to develop and validate methods for structural sizing of an airframe designed with the use of composite materials and active controls. This research program includes procedures for computing aeroelastic loads, static and dynamic aeroelasticity, analysis and synthesis of active controls, and optimization techniques. Development of the methods is concerned with the most effective ways of integrating and sequencing the procedures in order to generate structural sizing and the associated active control system, which is optimal with respect to a given merit function constrained by strength and aeroelasticity requirements.

Sobieszczanski-Sobieski, J.↗
NASA NTRS1997

Structural Analysis and Design Software

Collier Research and Development Corporation received a one-of-a-kind computer code for designing exotic hypersonic aircraft called ST-SIZE in the first ever Langley Research Center software copyright license agreement. Collier transformed the NASA computer code into a commercial software package called HyperSizer, which integrates with other Finite Element Modeling and Finite Analysis private-sector structural analysis program. ST-SIZE was chiefly conceived as a means to improve and speed the structural design of a future aerospace plane for Langley Hypersonic Vehicles Office. Including the NASA computer code into HyperSizer has enabled the company to also apply the software to applications other than aerospace, including improved design and construction for offices, marine structures, cargo containers, commercial and military aircraft, rail cars, and a host of everyday consumer products.

Source record↗
NASA NTRS1968

Predicted vibration responses of Apollo structure and effects of pressure correlation lengths on response

Progressive wove and reverberant acoustic fields ore often used in the laboratory for qualification testing of aerospace structures that are subjected to unsteady aerodynamic environments which occur during flight through the atmosphere. Acoustic simulation of these in-flight environments i s achieved i f the structural vibration response to acoustic excitation is equivalent, over the frequency range of interest, to the response caused by aerodynamic turbulence. To determine the degree of response simulation that could be expected for such qualification testing of the Apollo Spacecraft, responses of a segment of the Apollo structure were estimated theoretically for both acoustic and flight environments. The vibration analysis presented in this report was performed for the Spacecraft Lunar Module Adaptor; and the three environments treated are turbulence at Mach 1 and Mach 2, a reverberant acoustic field, and a modified acoustic progressive wave field. The progressive wave field is assumed to be generated within a specially designed shroud of sixteen axially oriented ducts which is constructed around and contoured to the external skin of the vehicle. Each duct is open on the side adjacent to the skin and is driven acoustically at one end by an independent noise source, thus allowing for different pressure correlation patterns around the circumference of the vehicle. The purpose of the analysis was to determine the effects of surface pressure correlation lengths on the response characteristics of representative Apollo structure, and to select on this basis, the optimum acoustic environment for structural vibration qualification tests of the Apollo in the Spacecraft Acoustic Laboratory at MSC. The method of analysis employed consists of determining, independently, the space average, mean-square acceleration spectral density for each of the significant modes of vibration of an equivalent cylindrical shell, and then expressing the total structural response as a linear summation of these modal responses. Approximately 570 classical modes of a pinned-end cylinder were used in order to find the spectral response characteristics of the structure throughout the frequency range of 10 - 1,000 Hz. The effective forcing functions or joint acceptances of the various modes of vibration were computed and are presented graphically for each of the pressure excitation environments. A brief development of the response equations used is presented in the report. Space average acceleration response spectra were computed for twelve different cases including aerodynamic turbulence at Mach 1 and Mach 2, reverberant acoustic field, five duct correlation patterns, two cases of an axially damped progressive wave field, and two cases in which the structural damping constant was varied from the expected value. The response spectra were computed and plotted by a high speed digital computer far a flat excitation pressure spectrum; and the response spectra were numerically integrated to give one-third octave bond average responses. A complete set of digital computer programs has been developed for both flat plate and cylindrical shell structures for the above environments, and each requires run times of three minutes or less. Thus, the work presented herein, along with the results, constitutes a practical advancement to the existing state-of-the-art of vibration prediction.

R W White↗
NASA NTRS1976

A new role for structures technology in aircraft configuration development

It is pointed out that decisions made during configuration development determine nearly 60% of the total program cost. The key to the new Structures Technology role considered is the development of integrated computer systems for structural design and analysis. Such systems make it possible to include structural sizing within the scope of preliminary configuration development. Analysis models are discussed, taking into account approaches used to determine the structural weight of an aircraft in the preliminary design stage, a finite element representation for a supersonic arrow wing transport, and the aerodynamic model. Attention is given to automated design considerations and a study which was conducted to reduce the aerodynamic drag of a supersonic transport by blending the structure of the wing and fuselage.

Nisbet, J. W.↗
NASA NTRS1980

A general logic structure for custom LSI'S

Structure composed of standardized-circuit arrays reduces cost and complexity of fabricating special integrated circuits. Desired circuits are formed from basic mask, custom cuts, and contact points. Interactive computer program speeds design.

Sievers, M. W.↗
NASA NTRS1979

Design, processing and testing of LSI arrays, hybrid microelectronics task

Mathematical cost models previously developed for hybrid microelectronic subsystems were refined and expanded. Rework terms related to substrate fabrication, nonrecurring developmental and manufacturing operations, and prototype production are included. Sample computer programs were written to demonstrate hybrid microelectric applications of these cost models. Computer programs were generated to calculate and analyze values for the total microelectronics costs. Large scale integrated (LST) chips utilizing tape chip carrier technology were studied. The feasibility of interconnecting arrays of LSU chips utilizing tape chip carrier and semiautomatic wire bonding technology was demonstrated.

Himmel, R. P.↗
NASA NTRS1983

Thermal-structural analysis of large space structures - An assessment of recent advances

Recent advances in modeling, analyzing, and understanding the thermal-structural responses of large space structures are reviewed, and uncertainties in the thermal-structural analysis are identified. Typical heat-load, thermal, and structural analyses requirements for large space structures are discussed using a design for a future large spacecraft as an example. The current status of heating, thermal, and structural analyses is then reviewed, and computer programs used in research and design are discussed. The need to develop efficient methods for integrating the interdisciplinary analyses is emphasized.

Thornton, E. A.↗
NASA NTRS1986

Effects of the low Earth orbital environment on spacecraft materials

It is evident from space flights during the last three years that the low Earth orbital (LEO) environment interacts with spacecraft surfaces in significant ways. One manifestation of these interactions is recession of, in particular, organic-polymer-based surfaces presumably due to oxidation by atomic oxygen, the major component of the LEO environment. Three experiments have been conducted on Space Shuttle flights 5, 8 and 41-G to measure reaction rates and the effects of various parameters on reaction rates. Surface recession on these flights indicates reaction efficiencies approximately 3 x 10(-24) cu cm/atoms for unfilled organic polymers. Of the metals, silver and osmium are very reactive. Effects on spacecraft or experiment surfaces can be evaluated using the derived reaction efficiencies and a definition of the total exposure to atomic oxygen. This exposure is obtained using an ambient density model, solar activity data and spacecraft parameters of altitude, attitude and operational date. Oxygen flux on a given surface is obtained from the ambient density and spacecraft velocity and can then be integrated to provide the total exposure or fluence. Such information can be generated using simple computational programs and can be converted to various formats. Overall, the extent of damage is strongly dependent on the type of surface and total exposure time.

Leger, L. J.↗
NASA NTRS1988

IDEAL: A methology for developing information systems

As a result of improved capabilities obtained through current computer technologies, application programs and expert systems, Enterprises are being designed or upgraded to be highly integrated and automated information systems. To design or modify Enterprises, it is necessary to first define what functions are to be performed within the Enterprise, identify which functions are potential candidates for automation, and what automated or expert systems are available, or must be developed, to accomplish the selected function. Second, it is necessary to define and analyze the informational requirements for each function along with the informational relationships among the functions so that a database structure can be established to support the Enterprise. To perform this type of system design, an integrated set of analysis tools is required to support the information analysis process. The IDEAL (Integrated Design and Engineering Analysis Languages) methodology provides this integrated set of tools and is discussed.

Evers, Ken H.↗