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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 451 records · Page 25

All sources NASA NTRS DOE OSTI

DOE OSTI2019

Quality Guidelines for Energy System Studies: Process Modeling Design Parameters

The National Energy Technology Laboratory (NETL) conducts systems analysis studies that require a large number of inputs, from ambient conditions to parameters for Aspen Plus® (Aspen) process blocks. The sheer number of assumptions required makes it impractical to document all of them in each issued report. The purpose of this section of the Quality Guidelines for Energy System Studies (QGESS) is to document the assumptions most commonly used in system analysis studies and the basis for those assumptions. In order to develop the systems analysis models presented in various NETL reports, significant vendor data has been obtained, and this data enhances the model outputs. Much of the vendor data obtained is considered proprietary and not suitable for public release, or attribution to a specific vendor. As such, several sub-systems common in NETL reports and their processparameter data are not reported in this document to protect proprietary vendor information.

42 ENGINEERING↗

NASA NTRS1981

Silicon production process evaluations

The chemical engineering analysis of the preliminary process design of a process for producing solar cell grade silicon from dichlorosilane is presented. A plant to produce 1,000 MT/yr of silicon is analyzed. Progress and status for the plant design are reported for the primary activities of base case conditions (60 percent), reaction chemistry (50 percent), process flow diagram (35 percent), energy balance (10 percent), property data (10 percent) and equipment design (5 percent).

Source record↗

DOE OSTI2013

The NSLS-II Alignment Coordinate System Conventions

For NSLS-II construction activities, a construction coordinate system is established with certain connections to geodetic NY State Plane Coordinate System, while physicists design the lattice and layout of accelerator and beam lines in a relatively dependent virtual space with their beam following coordinate system. In engineering design process, mechanical drawing designers, and beam line experts may both have their own coordinate system in a self-convenient manner. This situation will bring out problems of consistency and eventually lead to potential chaos for survey and alignment work. Therefore, it prompts to establish coordinate conventions recognized by all the relevant groups in order to smooth the coordinate processing flow when executing the alignment task according to specific design. Here descriptions about several existing coordinate system will be delineated and the definition of accelerator alignment coordinate system will be emphasized. The rotation and translation mathematical parameters will be given to allow for easy transformation. All the units are in meters. A programming code has been written to deal with a key requirement of integrating components’ fiducials into storage ring coordinate system. The parameters and code can be validated and tested by relevant groups.

36 MATERIALS SCIENCE↗

NASA NTRS2020

An Experimental Approach to a Rapid Propulsion and Aeronautics Concepts Testbed

Modern aircraft design tools have limitations for predicting complex propulsion-airframe interactions. The demand for new tools and methods addressing these limitations is high based on the many recent Distributed Electric Propulsion (DEP) Vertical Take-Off and Landing (VTOL) concepts being developed for Urban Air Mobility (UAM) markets. We propose that low cost electronics and additive manufacturing can support the conceptual design of advanced autonomy-enabled concepts, by facilitating rapid prototyping for experimentally driven design cycles. This approach has the potential to reduce complex aircraft concept development costs, minimize unique risks associated with the conceptual design, and shorten development schedule by enabling the determination of many "unknown unknowns" earlier in the design process and providing verification of the results from aircraft design tools. A modular testbed was designed and built to evaluate this rapid design-build-test approach and to support aeronautics and autonomy research targeting UAM applications utilizing a complex, transitioning-VTOL aircraft configuration. The testbed is a modular wind tunnel and flight model. The testbed airframe is approximately 80% printed, with labor required for assembly. This paper describes the design process, fabrication process, ground testing, and initial wind tunnel structural and thermal loading of a proof-of-concept aircraft, the Langley Aerodrome 8 (LA-8).

McSwain, Robert G.↗

NASA NTRS1974

Cost-effectiveness of integrated analysis/design systems /IPAD/ An executive summary. II

Evaluation of the cost-effectiveness of integrated analysis/design systems with particular attention to Integrated Program for Aerospace-Vehicle Design (IPAD) project. An analysis of all the ingredients of IPAD indicates the feasibility of a significant cost and flowtime reduction in the product design process involved. It is also concluded that an IPAD-supported design process will provide a framework for configuration control, whereby the engineering costs for design, analysis and testing can be controlled during the air vehicle development cycle.

Miller, R. E., Jr.↗

DOE OSTI2024

Design of Defensive Cybersecurity Architectures for High Temperature, Gas-Cooled Reactors

This report presents the design of defensive cybersecurity architectures (DCSAs) for High Temperature, Gas-Cooled Reactors (HTGRs). A DCSA is a cybersecurity design feature that places systems into security zones in a graded approach according to the importance of the functions performed by the systems. DCSA design efforts for advanced reactors may commence as early as the system-level design phase. This design approach is consistent with the draft regulatory guide for advanced reactor cybersecurity programs (DG-5075) and enables advanced reactor designers to consider the effects of security-by-design (SeBD) features on their DCSAs. Integration of DCSA design and other cybersecurity activities with the traditional design process as part of a SeBD framework may enable advanced reactor designers to improve the security posture of their plants while reducing implementation and operating costs. This report provides a DCSA template for an exemplar HTGR and describes a DCSA design process using event tree analysis so that the template may be optimized for a given HTGR design.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

NASA NTRS1994

Human factors certification in the development of future air traffic control systems

If human factors certification of aviation technologies aims to encompass the wide range of issues which need to be addressed for any new system, then human factors involvement must be present throughout the whole design process in a manner which relates to final certification. A certification process cannot simply be applied to the final product of design. Standards and guidelines will be required by designers at the outset of design for reference in preparing for certification. The most effective use of human factors principles, methods, and measures is made as part of an iterative design process, leading to a system which reflects these as far as possible. This particularly applies where the technology is complex and may be represented by a number of components or sub-systems. Some aspects of the system are best certified during early prototyping, when there is still scope to make changes to software or hardware. At this stage in design, financial and/or time pressures will not rule out the possibility of necessary changes, as may be the case later. Other aspects of the system will be best certified during the final phases of design when the system is in a more complete form and in a realistic environment.

Evans, Alyson E.↗

NASA NTRS1984

Error detection process - Model, design, and its impact on computer performance

An analytical model is developed for computer error detection processes and applied to estimate their influence on system performance. Faults in the hardware, not in the design, are assumed to be the potential cause of transition to erroneous states during normal operations. The classification properties and associated recovery methods of error detection are discussed. The probability of obtaining an unreliable result is evaluated, along with the resulting computational loss. Error detection during design is considered and a feasible design space is outlined. Extension of the methods to account for the effects of extant multiple faults is indicated.

Shin, K. G.↗

NASA NTRS1987

Thermal design, analysis and testing of the Halogen Occultation Experiment

This paper briefly introduces the Halogen Occultation Experiment (HALOE) and describes the thermal requirements in some detail. The thermal design of the HALOE is described, together with the design process and the analytical techniques used to arrive at this design. The flight hardware has undergone environmental testing in a thermal vacuum chamber to validate the thermal design. The HALOE is a unique problem in thermal control due to its variable solar loading, its extremely sensitive optical components and the high degree of pointing accuracy required. This paper describes the flight hardware, the design process and its verification.

Foss, Richard A.↗

NASA NTRS1989

Multidisciplinary optimization for engineering systems: Achievements and potential

The currently common sequential design process for engineering systems is likely to lead to suboptimal designs. Recently developed decomposition methods offer an alternative for coming closer to optimum by breaking the large task of system optimization into smaller, concurrently executed and, yet, coupled tasks, identified with engineering disciplines or subsystems. The hierarchic and non-hierarchic decompositions are discussed and illustrated by examples. An organization of a design process centered on the non-hierarchic decomposition is proposed.

Sobieszczanski-Sobieski, Jaroslaw↗

NASA NTRS1989

Multidisciplinary optimization for engineering systems - Achievements and potential

Sobieszczanski-Sobieski, Jaroslaw↗

DOE OSTI2014

Turbulent Flow Effects on the Biological Performance of Hydro-Turbines

The hydro-turbine industry uses Computational Fluid Dynamics (CFD) tools to predict the flow conditions as part of the design process for new and rehabilitated turbine units. Typically the hydraulic design process uses steady-state simulations based on Reynolds-Averaged Navier-Stokes (RANS) formulations for turbulence modeling because these methods are computationally efficient and work well to predict averaged hydraulic performance, e.g. power output, efficiency, etc. However, in view of the increasing emphasis on environmental concerns, such as fish passage, the consideration of the biological performance of hydro-turbines is also required in addition to hydraulic performance. This leads to the need to assess whether more realistic simulations of the turbine hydraulic environment -those that resolve unsteady turbulent eddies not captured in steady-state RANS computations- are needed to better predict the occurrence and extent of extreme flow conditions that could be important in the evaluation of fish injury and mortality risks. In the present work, we conduct unsteady, eddy-resolving CFD simulations on a Kaplan hydro-turbine at a normal operational discharge. The goal is to quantify the impact of turbulence conditions on both the hydraulic and biological performance of the unit. In order to achieve a high resolution of the incoming turbulent flow, Detached Eddy Simulation (DES) turbulence model is used. These transient simulations are compared to RANS simulations to evaluate whether extreme hydraulic conditions are better captured with advanced eddy-resolving turbulence modeling techniques. The transient simulations of key quantities such as pressure and hydraulic shear flow that arise near the various components (e.g. wicket gates, stay vanes, runner blades) are then further analyzed to evaluate their impact on the statistics for the lowest absolute pressure (nadir pressures) and for the frequency of collisions that are known to cause mortal injury in fish passing through hydro-turbines.

42 ENGINEERING↗

NASA NTRS2002

Advances in space radiation shielding codes

Early space radiation shield code development relied on Monte Carlo methods and made important contributions to the space program. Monte Carlo methods have resorted to restricted one-dimensional problems leading to imperfect representation of appropriate boundary conditions. Even so, intensive computational requirements resulted and shield evaluation was made near the end of the design process. Resolving shielding issues usually had a negative impact on the design. Improved spacecraft shield design requires early entry of radiation constraints into the design process to maximize performance and minimize costs. As a result, we have been investigating high-speed computational procedures to allow shield analysis from the preliminary concept to the final design. For the last few decades, we have pursued deterministic solutions of the Boltzmann equation allowing field mapping within the International Space Station (ISS) in tens of minutes using standard Finite Element Method (FEM) geometry common to engineering design methods. A single ray trace in such geometry requires 14 milliseconds and limits application of Monte Carlo methods to such engineering models. A potential means of improving the Monte Carlo efficiency in coupling to spacecraft geometry is given.

manned↗

NASA NTRS1977

Integrated circuit process and design rule evaluation techniques

A technique is described for determining the applicability of a particular process for the fabrication of large-scale integrated (LSI) circuits. Test arrays were developed to isolate various critical processing steps in a fabrication sequence and a statistical evaluation of these steps was carried out that related yield or success in achieving a desired result to the number of times the results were attempted. It was found that, in general, yield is a sensitive function of physical dimensions as is the packing density of a particular array. It is, therefore, possible to generate an optimum set of physical dimensions or design rules that maximize the expected number of working circuits on a wafer.

Ipri, A. C.↗

NASA NTRS1987

Application of decomposition techniques to the preliminary design of a transport aircraft

A nonlinear constrained optimization problem describing the preliminary design process for a transport aircraft has been formulated. A multifaceted decomposition of the optimization problem has been made. Flight dynamics, flexible aircraft loads and deformations, and preliminary structural design subproblems appear prominently in the decomposition. The use of design process decomposition for scheduling design projects, a new system integration approach to configuration control, and the application of object-centered programming to a new generation of design tools are discussed.

Rogan, J. E.↗

NASA NTRS1989

Aerolastic tailoring and integrated wing design

Much has been learned from the TSO optimization code over the years in determining aeroelastic tailoring's place in the integrated design process. Indeed, it has become apparent that aeroelastic tailoring is and should be deeply embedded in design. Aeroelastic tailoring can have tremendous effects on the design loads, and design loads affect every aspect of the design process. While optimization enables the evaluation of design sensitivities, valid computational simulations are required to make these sensitivities valid. Aircraft maneuvers simulated must adequately cover the plane's intended flight envelope, realistic design criteria must be included, and models among the various disciplines must be calibrated among themselves and with any hard-core (e.g., wind tunnel) data available. The information gained and benefits derived from aeroelastic tailoring provide a focal point for the various disciplines to become involved and communicate with one another to reach the best design possible.

Love, Mike H.↗

DOE OSTI2015

Solving the Big Data (BD) Problem in Advanced Manufacturing (Subcategory for work done at Georgia Tech. Study Process and Design Factors for Additive Manufacturing Improvement)

3D printing originally known as additive manufacturing is a process of making 3 dimensional solid objects from a CAD file. This ground breaking technology is widely used for industrial and biomedical purposes such as building objects, tools, body parts and cosmetics. An important benefit of 3D printing is the cost reduction and manufacturing flexibility; complex parts are built at the fraction of the price. However, layer by layer printing of complex shapes adds error due to the surface roughness. Any such error results in poor quality products with inaccurate dimensions. The main purpose of this research is to measure the amount of printing errors for parts with different geometric shapes and to analyze them for finding optimal printing settings to minimize the error. We use a Design of Experiments framework, and focus on studying parts with cone and ellipsoid shapes. We found that the orientation and the shape of geometric shapes have significant effect on the printing error. From our analysis, we also determined the optimal orientation that gives the least printing error.

36 MATERIALS SCIENCE↗

NASA NTRS1984

STAEBL: Structural tailoring of engine blades, phase 2

The Structural Tailoring of Engine Blades (STAEBL) program was initiated at NASA Lewis Research Center in 1980 to introduce optimal structural tailoring into the design process for aircraft gas turbine engine blades. The standard procedure for blade design is highly iterative with the engineer directly providing most of the decisions that control the design process. The goal of the STAEBL program has been to develop an automated approach to generate structurally optimal blade designs. The program has evolved as a three-phase effort with the developmental work being performed contractually by Pratt & Whitney Aircraft. Phase 1 was intended as a proof of concept in which two fan blades were structurally tailored to meet a full set of structural design constraints while minimizing DOC+I (direct operating cost plus interest) for a representative aircraft. This phase was successfully completed and was reported in reference 1 and 2. Phase 2 has recently been completed and is the basis for this discussion. During this phase, three tasks were accomplished: (1) a nonproprietary structural tailoring computer code was developed; (2) a dedicated approximate finite-element analysis was developed; and (3) an approximate large-deflection analysis was developed to assess local foreign object damage. Phase 3 is just beginning and is designed to incorporated aerodynamic analyses directly into the structural tailoring system in order to relax current geometric constraints.

Hirschbein, M. S.↗