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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 631 records · Page 35
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Community Solar Subscription Credit Considerations and Case Study

Together New Orleans (TNO) requested technical assistance through the US Department of Energy's (DOE's) National Community Solar Partnership (NCSP). The National Community Solar Partnership is a coalition of community solar stakeholders working to expand access to affordable community solar to every U.S. household and enable subscribers and their communities to realize meaningful benefits, such as reduced energy burden, increased resilience, community ownership, and equitable workforce development. TNO asked for a subject matter expert from NCSP to review the Entergy New Orleans (ENO) proposed revised Rate Schedule for Community Solar Generating Facilities. TNO requested that the proposed methodology for subscription credits for applicable residential and non-residential rate schedules be reviewed to determine the expected credit rate. The aim behind the analysis is to provide TNO and engaged stakeholders with an informed understanding of the proposed rate schedule before making decisions on the appropriate rate design for community solar (CS) subscriptions. This report is an exploration of CS subscription credit rate calculation considerations using the CS program in New Orleans as a case study. The report provides a framework for modeling CS credit rates in addition to topics that may be helpful to address when undertaking program design or rule making.

14 SOLAR ENERGY↗
NASA NTRS1974

Heat Transfer and Fluid Mechanics Institute, 24th, Oregon State University, Corvallis, Ore., June 12-14, 1974, Proceedings

Recent theoretical and experimental studies in heat transfer and fluid mechanics, including some environmental protection investigations, are presented in a number of papers. Some of the topics covered include condensation heat transfer, a model of turbulent momentum and heat transfer at points of separation and reattachment, an explicit scheme for calculations of confined turbulent flows with heat transfer, heat transfer effects on a delta wing in subsonic flow, fluid mechanics of ocean outfalls, thermal plumes from industrial cooling water, a photochemical air pollution model for the Los Angeles air basin, and a turbulence model of diurnal variations in the planetary boundary layer. Individual items are announced in this issue.

Davis, L. R.↗
NASA NTRS1974

Specialists Meeting on Rotorcraft Dynamics, Moffett Field, Calif., February 13-15, 1974, Proceedings

Analysis of specific problems in rotorcraft dynamics. Topics include hingeless rotor theory, dynamic stall modelling, periodic systems identification, analysis of complex systems with phasing matrices, flapping stability, flap-lag dynamics at high advance ratios, finite element analysis and fuselage free-vibration characteristics, coupled rotor/frame vibration methods, gust response characteristics with unsteady stall effects, antiresonance theory, cyclic feathering motions and dynamic loads, control load envelope shaping, rotor aeroelasticity, use of Floquet theory, theory of proprotors and tilt-rotors, two-bladed teetering rotors, stability of air and ground resonance, vertical-plane pendulum absorbers, multicyclic jet-flap control, engine/frame interface dynamics, and others. The minutes of the question and answer periods following the presentations are presented in the supplement. Individual items are announced in this issue.

Source record↗
NASA NTRS1974

Investigation of the starting transients of high performance solid-propellant motors

The starting transients of solid propellant engines were investigated to develop design principles for predicting transients in high performance igniter and engine configurations. Research and diagnosis were conducted on the processes affecting ignition transients, such as heat flux, igniter, flame spreading over the surface, and nonsteady combustion gas dynamics. Abstracts of published reports related to this research are presented. Topics discussed include: development of an analytical model, analytical prediction of the entire ignition transient, transient behavior of pressure and regression rate during reignition after shut-down, and problems associated with restarting hybrid rocket engines.

Summerfield, M.↗
NASA NTRS1976

Elementary Applications of a Rotorcraft Dynamic Stability Analysis

A number of applications of a rotorcraft aeroelastic analysis are presented to verify that the analysis encompasses the classical solutions of rotor dynamics, and to examine the influence of certain features of the model. Results are given for the following topics: flapping frequency response to pitch control; forward flight flapping stability; pitch/flap flutter and divergence; ground resonance instability; and the flight dynamics of several representative helicopters.

Johnson, W.↗
NASA NTRS1978

Helium glow detector experiment, MA-088

Of the two 584 A channels in the helium glow detector, channel #1 appeared to provide data with erratic count rates and undue susceptibility to dayglow and solar contamination possibly because of filter fatigue or failure. Channel #3 data appear normal and of high quality. For this reason only data from this last channel was analyzed and used for detailed comparison with theory. Reduction and fitting techniques are described, as well as applications of the data in the study of nighttime and daytime Hel 584 A emission. A hot model of the interstellar medium is presented. Topics covered in the appendix include: observations of interstellar helium with a gas absorption cell: implications for the structure of the local interstellar medium; EUV dayglow observations with a helium gas absorption cell; and EUV scattering from local interstellar helium at nonzero temperatures: implications for the derivations of interstellar medium parameters.

Bowyer, C. S.↗
NASA NTRS1981

Charge-exchange plasma environment for an ion drive spacecraft

A model was reviewed which describes the propagation of the mercury charge-exchange plasma and extended to describe the flow of the molybdenum component of the charge-exchange plasma. The uncertainties in the models for various conditions are discussed. Such topics as current drain to the solar array, charge-exchange plasma material deposition, and the effects of space plasma on the charge-exchange plasma propagation are addressed.

Kaufman, H. R.↗
NASA NTRS1983

Experimental study of main rotor/tail rotor/airframe interactions in hover. Volume 1: Text and figures

To assist in identifying and quantifying the relevant parameters associated with the complex topic of main rotor/fuselage/tail rotor interference, a model scale hover test was conducted in the Model Rotor Hover Facility. The test was conducted using the basic model test rig, fuselage skins to represent a UH-60A BLACK HAWK helicopter, 4 sets of rotor blades of varying geometry (i.e., twist, airfoils and solidity) and a model tail rotor that could be relocated to give changes in rotor clearance (axially, laterally, and vertically), can't angle and operating model (pusher or tractor). The description of the models and the tests, data analysis and summary (including plots) are included. The customary system of units gas used for principal measurements and calculations. Expressions in both SI units and customary units are used with the SI units stated first and the customary units afterwords, in parenthesis.

Balch, D. T.↗
NASA NTRS1983

Advances and trends in structural and solid mechanics; Proceedings of the Symposium, Washington, DC, October 4-7, 1982

The mechanics of materials and material characterization are considered, taking into account micromechanics, the behavior of steel structures at elevated temperatures, and an anisotropic plasticity model for inelastic multiaxial cyclic deformation. Other topics explored are related to advances and trends in finite element technology, classical analytical techniques and their computer implementation, interactive computing and computational strategies for nonlinear problems, advances and trends in numerical analysis, database management systems and CAD/CAM, space structures and vehicle crashworthiness, beams, plates and fibrous composite structures, design-oriented analysis, artificial intelligence and optimization, contact problems, random waves, and lifetime prediction. Earthquake-resistant structures and other advanced structural applications are also discussed, giving attention to cumulative damage in steel structures subjected to earthquake ground motions, and a mixed domain analysis of nuclear containment structures using impulse functions.

Noor, A. K.↗
NASA NTRS1984

PAN AIR modeling studies. II - Sideslip option, network gaps, three-dimensional forebody flow, and thick-trailing-edge representation

PAN AIR is a computer program that calculates linear potential flow about arbitrary configurations at both subsonic and supersonic Mach numbers. This paper is a follow-on of another paper entitled 'PAN AIR Modeling Studies', in which several studies were presented that exhibited PAN AIR's versatility for modeling diverse configurations. Results from four modeling studies of interest in modeling realistic aircraft shapes are presented. The topics addressed are (1) half-geometry option in sideslip, (2) network gaps, (3) three-dimensional forebody flows, and (4) trailing-edge representation.

Strande, S.↗
NASA NTRS1988

A summary of recent NASA/Army contributions to rotorcraft vibrations and structural dynamics technology

The requirement for low vibrations has achieved the status of a critical design consideration in modern helicopters. There is now a recognized need to account for vibrations during both the analytical and experimental phases of design. Research activities in this area were both broad and varied and notable advances were made in recent years in the critical elements of the technology base needed to achieve the goal of a jet smooth ride. The purpose is to present an overview of accomplishments and current activities of govern and government-sponsored research in the area of rotorcraft vibrations and structural dynamics, focusing on NASA and Army contributions over the last decade or so. Specific topics addressed include: airframe finite-element modeling for static and dynamic analyses, analysis of coupled rotor-airframe vibrations, optimization of airframes subject to vibration constraints, active and passive control of vibrations in both the rotating and fixed systems, and integration of testing and analysis in such guises as modal analysis, system identification, structural modification, and vibratory loads measurement.

Kvaternik, Raymond G.↗
NASA NTRS1988

Applications of nonlinear systems theory to control design

For most applications in the control area, the standard practice is to approximate a nonlinear mathematical model by a linear system. Since the feedback linearizable systems contain linear systems as a subclass, the procedure of approximating a nonlinear system by a feedback linearizable one is examined. Because many physical plants (e.g., aircraft at the NASA Ames Research Center) have mathematical models which are close to feedback linearizable systems, such approximations are certainly justified. Results and techniques are introduced for measuring the gap between the model and its truncated linearizable part. The topic of pure feedback systems is important to the study.

Hunt, L. R.↗
NASA NTRS1988

Applications of nonlinear systems theory to control design

For most applications in the control area, the standard practice is to approximate a nonlinear mathematical model by a linear system. Since the feedback linearizable systems contain linear systems as a subclass, the procedure of approximating a nonlinear system by a feedback linearizable one is examined. Because many physical plants (e.g., aircraft at the NASA Ames Research Center) have mathematical models which are close to feedback linearizable systems, such approximations are certainly justified. Results and techniques are introduced for measuring the gap between the model and its truncated linearizable part. The topic of pure feedback systems is important to the study.

Hunt, L. R.↗
NASA NTRS1989

The case for Mars III: Strategies for exploration - Technical

Papers on issues related to Mars exploration are presented, covering topics such as the social implications of manned missions to Mars, mission strategies, mission designs, the economics of a Mars mission, Space Station support for a Mars mission, a Diagnostic and Environmental Monitoring System, and a zero-g CELSS/recreation facility for an earth/Mars crew shuttle. Other topics include biomedical concerns and fitness in spaceflight, spaceflight environment habitability, the Mars Rover/Sample Return Mission, a rooitic Mars surface sampler, a Mars Orbiter, and scientific goals of Mars exploration. Additional topics include Space Station evolution, mission options, modeling advanced space systems, computer support for Mars missions, launch system options, advanced propulsion techniques, the utilization of resources on Mars, the development of a Martian base, and options for mobility on Mars.

Stoker, Carol R.↗
NASA NTRS1990

A methodology for evaluating the reliability and risk of structures under complex service environments

The theoretical basis and numerical implementation of NESSUS (Numerical Evaluation of Stochastic Structures Under Stress), a computer code for probabilistic structural analysis of aerospace components, are described, with an emphasis on the use of NESSUS for reliability and risk assessment. Topics addressed include the structure of probabilistic models of fatigue-crack initiation, risk/cost evaluation, fatigue-fracture analysis, and fatigue-crack initiation. Numerical results from typical applications are presented in graphs and briefly characterized. The usefulness of NESSUS predictions for establishing inspection and retirement schedules and for component certification is indicated.

Shiao, Michael C.↗
NASA NTRS1987

CFD validation experiments at McDonnell Aircraft Company

Information is given in viewgraph form on computational fluid dynamics (CFD) validation experiments at McDonnell Aircraft Company. Topics covered include a high speed research model, a supersonic persistence fighter model, a generic fighter wing model, surface grids, force and moment predictions, surface pressure predictions, forebody models with 65 degree clipped delta wings, and the low aspect ratio wing/body experiment.

Verhoff, August↗
NASA NTRS1996

Studying Turbulence Using Numerical Simulation Databases: Proceedings of the 1996 Summer Program - Part 6

Topics considered include: New approach to turbulence modeling; Second moment closure analysis of the backstep flow database; Prediction of the backflow and recovery regions in the backward facing step at various Reynolds numbers; Turbulent flame propagation in partially premixed flames; Ensemble averaged dynamic modeling. Also included a study of the turbulence structures of wall-bounded shear flows; Simulation and modeling of the elliptic streamline flow.

Source record↗