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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 811 records · Page 45
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Engineering Computational Practices (Rev. 1)

This manual will attempt to motivate the use of an automated build system for the purposes of computational science and engineering. As part of this motivation, the surrounding computational practices of version control, documen tation, compute environment management, and regression testing will also be addressed as applied to the practice of computational engineering. Specifically, this manual intends to motivate the adoption of these traditional software engineering practices for use in research and production engineering simulation projects. This manual is not the first such effort in the greater scientific computing community. In fact, the authors relied heavily on the lesson plans of the Software Carpentry, established to teach computing skills to researchers in 1998. As the intention for this manual is to lay out fundamental practices of engineering computing, it will not attempt to fully teach the underlying concepts and will instead reference the well designed lesson plans of the Software Carpentry. Where possible, this manual will explain to general computing practices and concepts and limit discussion of specific software implementations to examples or vehicles for practice in concrete application. The specific software taught by the Software Carpentry curriculum is an excellent starting point to learn the core concepts of computational engi neering. However, the authors have found that applications to engineering simulation and analysis require translation of these software development concepts into the language and workflows of computational engineers. Adopting these computational tools may require engineers to re-imagine their workflows in some combination of traditional engineer ing and software concepts. It has also been necessary to extend existing software build systems for engineering practices beyond the simple wrap ping of engineering software execution. Where necessary, examples of specific software and their method of extension to engineering simulations will be given, with reference to the User Manual for recommended practical use. Where this manual relies on specific implementation examples, it should be understood that the practicing engineer may find that different software is more amenable to their specific work. It is always the overall collection of computational practices is more important than any specific software implementation. The ability to recognize which concepts are implemented by a software package will make a practicing engineer agile to changing project needs, computing resources, numeric solvers, programming languages, and even available funding.

42 ENGINEERING↗
DOE OSTI2023

Basic Research Needs in Quantum Computing and Networking

Employing quantum mechanical resources in computing, information processing, and networking opens the door to potential exponential advantages over classical counterparts. However, quantifying and realizing such advantages poses extensive scientific and engineering challenges. Department of Energy (DOE) investments have driven steady progress in addressing such challenges. Recently developed quantum algorithms offer asymptotic exponential advantages in speed or accuracy for fundamental scientific problems. These problems include simulating physical systems, solving systems of linear equations, differential equations, and optimization problems. Empirical demonstrations on nascent quantum hardware suggest better performance on contrived computational tasks than classical analogs. However, the requirements for a quantum computer or network to demonstrate an end-to-end rigorously quantifiable performance improvement over classical analogs remains a grand challenge, especially for problems of practical value. In particular, what will be required for quantum technology to ultimately exhibit scalable, rigorous, and transformative performance advantages for practical applications? In July 2023, DOE’s Advanced Scientific Computing Research program in the Office of Science convened the Workshop on Basic Research Needs in Quantum Computing and Networking, where major opportunities and grand challenges were identified. The following five priority research directions (PRDs) were identified as a result of the workshop.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2026

Genesis Mission Data cards

As data-intensive research and artificial intelligence become central to DOE mission science, the need for machine-actionable dataset documentation has grown accordingly. However, many DOE-aligned communities, including the Office of Science, NNSA, and cross-laboratory collaborations, have developed independent metadata practices. This fragmentation creates friction for discovery, federation, and reuse across programs. To address these challenges, this talk introduces the Genesis Data Card: a shared metadata artifact developed in collaboration with a broad DOE community (Jefferson Lab and the National Lab of the Rockies, Oak Ridge, Sandia, Idaho, Berkeley, and Los Alamos). The Genesis Data Card aims to standardize dataset documentation across DOE-aligned initiatives while remaining extensible to discipline-specific needs. This talk will describe the data card template and the supporting code to validate completed data cards, using a companion LinkML schema. I'll walk through the design decisions behind the template, its alignment with existing standards, its treatment of sensitivity and governance metadata, and the phased roadmap toward lifecycle-integrated "xCards" that support autonomous discovery and reuse. The talk closes with current gaps, ongoing work, and how others can contribute datasets and feedback to the shared repository.

McSpadden, Helen [Thomas Jefferson National Accele↗
NASA NTRS1972

Mechanical systems readiness assessment.

Development of a methodology for applying structure-borne acoustics to the readiness assessment, fault isolation, and automatic checkout of mechanical devices. The twofold objective of the study was to determine the practical feasibility of implementing structure-borne acoustics on future space programs and to provide guidelines toward minimization of cost and effort in the implementation of this technique. It is concluded that the structure-borne acoustics technique lends itself to reducing checkout, operation, maintenance, and fault diagnosis of mechanical systems.

Kitchel, D.↗
NASA NTRS1976

Disturbing effects of attitude control maneuvers on the orbital motion of the Helios spacecraft

The position of the spin axis of the Helios A spacecraft has been maintained and updated by a series of attitude control maneuvers, by means of a sequence of unbalanced jet forces which produce an additional disturbed motion of the spacecraft's center of mass. The character of this motion, its magnitude and direction was studied. For practical purposes of the orbit determination of the spacecraft, a computer program is given which shows how the components of the disturbing acceleration in the spacecraft-fixed reference frame can be easily computed.

Georgevic, R. M.↗
NASA NTRS1979

Axial-flow turbopumps

Monograph organizes and presents significant experience and knowledge accumulated by NASA in development and operational programs. It assists system designers. It reviews and assesses current design practices and from them establishes guidance for achieving greater consistency in design, increased reliability in end product, and greater efficiency in design effort.

Source record↗
NASA NTRS1979

Active flutter control for flexible vehicles, volume 1

An active flutter control methodology based on linear quadratic gaussian theory and its application to the control of a super critical wing is presented. Results of control surface and sensor position optimization are discussed. Both frequency response matching and residualization used to obtain practical flutter controllers are examined. The development of algorithms and computer programs for flutter modeling and active control design procedures is reported.

Mahesh, J. K.↗
NASA NTRS1981

A comprehensive model to determine the effects of temperature and species fluctuations on reactions in turbulent reacting flows

The joint probability distribution function (pdf), which is a modification of the bivariate Gaussian pdf, is discussed and results are presented for a global reaction model using the joint pdf. An alternative joint pdf is discussed. A criterion which permits the selection of temperature pdf's in different regions of turbulent, reacting flow fields is developed. Two principal approaches to the determination of reaction rates in computer programs containing detailed chemical kinetics are outlined. These models represent a practical solution to the modeling of species reaction rates in turbulent, reacting flows.

Antaki, P. J.↗
NASA NTRS1982

A study of microwave downcoverters operating in the K sub u band

A computer program for parametric amplifier design is developed with special emphasis on practical design considerations for microwave integrated circuit degenerate amplifiers. Precision measurement techniques are developed to obtain a more realistic varactor equivalent circuit. The existing theory of a parametric amplifier is modified to include the equivalent circuit, and microwave properties, such as loss characteristics and circuit discontinuities are investigated.

Fellers, R. G.↗
NASA NTRS1987

Surface contamination monitoring by the measurement of scattering distribution functions

This paper describes the use of Bidirectional Scattering Distribution Functions (BSDF) to quantify surface degradation, thus providing an effective method for contamination monitoring. This approach to contamination monitoring is based on the use of witness surfaces (mirrors or glass slides) located next to the critical surfaces. Contaminant accretion can be monitored during all phases of spacecraft fabrication, assembly, and testing. The method can be applied in other areas of contamination control such as monitoring of clean room environments. The BSDF can also prove extremely useful in establishing contamination control requirements and acceptability criteria. This paper describes the apparatus adopted to perform BSDF measurements and discusses some practical aspects of data collection. The results obtained in contamination monitoring programs performed at the NASA Goddard Space Flight Center are presented. Some possible new applications of this monitoring technique are also addressed.

Carosso, Paola A.↗
NASA NTRS1987

Cooperative analysis expert situation assessment research

For the past few decades, Rome Air Development Center (RADC) has been conducting research in Artificial Intelligence (AI). When the recent advances in hardware technology made many AI techniques practical, the Intelligence and Reconnaissance Directorate of RADC initiated an applications program entitled Knowledge Based Intelligence Systems (KBIS). The goal of the program is the development of a generic Intelligent Analyst System, an open machine with the framework for intelligence analysis, natural language processing, and man-machine interface techniques, needing only the specific problem domain knowledge to be operationally useful. The development of KBIS is described.

Mccown, Michael G.↗
NASA NTRS1989

A systems engineering management approach to resource management applications

The author presents a program management response to the following question: How can the traditional practice of systems engineering management, including requirements specification, be adapted, enhanced, or modified to build future planning and scheduling systems for effective operations? The systems engineering management process, as traditionally practiced, is examined. Extensible resource management systems are discussed. It is concluded that extensible systems are a partial solution to problems presented by requirements that are incomplete, partially immeasurable, and often dynamic. There are positive indications that resource management systems have been characterized and modeled sufficiently to allow their implementation as extensible systems.

Hornstein, Rhoda Shaller↗
NASA NTRS1997

Summer Research Internships at Biosphere 2 Center

Through the support of NASA's Mission to Planet Earth, Biosphere 2 Center hosted 11 research interns for 6 to 8 weeks each during the summer of 1997. In addition, we were able to offer scholarships to 14 students for Columbia University summer field courses. These two types of programs engaged students in much of the range of activity of practicing Earth Scientists, with an emphasis on the collection and analysis of data in both the field and the laboratory. Research interns and students in the field courses also played an important part in the design and evolution of their research projects. In addition to laboratory and field research, students participated in weekly research seminars by resident and visiting scientists. Research interns were exposed to the geology and ecology of the region via short field trips to the Arizona Sonora Desert Museum, Mount Lemmon, Aravaipa Canyon and the Gulf of California, while field course students were exposed to laboratory-based research via intern-led hands-on demonstrations of their work. All students made oral and written presentations of their work during the summer, and two of the research interns have applied to present their results at the National Conference on Undergraduate Research in Maryland in April, 1998.

Broecker, Wallace S.↗
NASA NTRS2000

NASA's New Approach for Evaluating Risk Reduction Due to Space Shuttle Upgrades

As part of NASA's intensive effort to incorporate quantitative risk assessment (QRA) tools in the Agency's decision-making process concerning Space Shuttle risk, NASA has developed a powerful risk assessment tool called the Quantitative Risk Assessment System (QRAS). The QRAS is a tool designed to estimate Space Shuttle risk and evaluate Space Shuttle upgrades. This paper presents an overview of the QRAS with focus on its application for evaluating the risk reduction due to proposed Space Shuttle upgrades. The application includes a case study from the Space Shuttle main engine (SSME). The QRAS overview section of the paper includes the QRAS development process, the technical approach to model development, the QRA quantification methods and techniques, and observations concerning the complex modeling involved in QRAS. The application section of the paper describes a practical case study using QRAS models for evaluating critical Space Shuttle Program upgrades, specifically a proposed SSME nozzle upgrade. This paper presents the method for evaluating the proposed upgrade by comparing the current nozzle (old design with well-established probabilistic models) to the channel wall nozzle (new design at the preliminary design level).

Safie, Fayssal M.↗
NASA NTRS2000

A Parallel Genetic Algorithm for Automated Electronic Circuit Design

We describe a parallel genetic algorithm (GA) that automatically generates circuit designs using evolutionary search. A circuit-construction programming language is introduced and we show how evolution can generate practical analog circuit designs. Our system allows circuit size (number of devices), circuit topology, and device values to be evolved. We present experimental results as applied to analog filter and amplifier design tasks.

Lohn, Jason D.↗
NASA NTRS2001

Probabilistic Risk-Based Approach to Aeropropulsion System Assessment Developed

In an era of shrinking development budgets and resources, where there is also an emphasis on reducing the product development cycle, the role of system assessment, performed in the early stages of an engine development program, becomes very critical to the successful development of new aeropropulsion systems. A reliable system assessment not only helps to identify the best propulsion system concept among several candidates, it can also identify which technologies are worth pursuing. This is particularly important for advanced aeropropulsion technology development programs, which require an enormous amount of resources. In the current practice of deterministic, or point-design, approaches, the uncertainties of design variables are either unaccounted for or accounted for by safety factors. This could often result in an assessment with unknown and unquantifiable reliability. Consequently, it would fail to provide additional insight into the risks associated with the new technologies, which are often needed by decisionmakers to determine the feasibility and return-on-investment of a new aircraft engine.

Tong, Michael T.↗
NASA NTRS2003

Software for Managing Parametric Studies

The Information Power Grid Virtual Laboratory (ILab) is a Practical Extraction and Reporting Language (PERL) graphical-user-interface computer program that generates shell scripts to facilitate parametric studies performed on the Grid. (The Grid denotes a worldwide network of supercomputers used for scientific and engineering computations involving data sets too large to fit on desktop computers.) Heretofore, parametric studies on the Grid have been impeded by the need to create control language scripts and edit input data files painstaking tasks that are necessary for managing multiple jobs on multiple computers. ILab reflects an object-oriented approach to automation of these tasks: All data and operations are organized into packages in order to accelerate development and debugging. A container or document object in ILab, called an experiment, contains all the information (data and file paths) necessary to define a complex series of repeated, sequenced, and/or branching processes. For convenience and to enable reuse, this object is serialized to and from disk storage. At run time, the current ILab experiment is used to generate required input files and shell scripts, create directories, copy data files, and then both initiate and monitor the execution of all computational processes.

Yarrow, Maurice↗