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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 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Performance, physiological, and oculometer evaluation of VTOL landing displays

A methodological approach to measuring workload was investigated for evaluation of new concepts in VTOL aircraft displays. Physiological, visual response, and conventional flight performance measures were recorded for landing approaches performed in the NASA Visual Motion Simulator (VMS). Three displays (two computer graphic and a conventional flight director), three crosswind amplitudes, and two motion base conditions (fixed vs. moving base) were tested in a factorial design. Multivariate discriminant functions were formed from flight performance and/or visual response variables. The flight performance variable discriminant showed maximum differentation between crosswind conditions. The visual response measure discriminant maximized differences between fixed vs. motion base conditions and experimental displays. Physiological variables were used to attempt to predict the discriminant function values for each subject/condition trial. The weights of the physiological variables in these equations showed agreement with previous studies. High muscle tension, light but irregular breathing patterns, and higher heart rate with low amplitude all produced higher scores on this scale and thus represent higher workload levels.

North, R. A.↗
NASA NTRS1980

Plaid evaluation of visual access for PDP berthing and deployment

Tests were performed to evaluate visual access for berthing and deployment of the Plasma Diagnostic Package (PDP) in Space Transportation 4 Flight (STS-4). The Panel Layout Automated Interactive Design (PLAID), a 3 D computer graphics package, was used to construct models of the PDP, pallet, orbiter payload bay, the Remote Manipulator System (RMS), and other relevant elements to represent the STS-4 configuration. Several different assemblies were made, each one representing a snapshot of the PDP during berth/deploy maneuvers. Thirty-six views were produced during this test.

Brown, J. W.↗
NASA NTRS1979

Laser anemometer measurements at the exit of a T63 combustor

In the first practical application of laser anemometry to an actual gas turbine engine combustor, the mean velocity and turbulent intensity profiles were measured in a steady-flow combustion rig across an annulus simulating a turbine inlet; to establish a basis for comparison with similar measurements to be made in an operating engine and to confirm current turbine aerodynamics and heat transfer design assumptions. It was necessary to develop a new experimental technique for traversing the annulus due to differential thermal expansion of the cantilevered combustion rig and a new computer-graphics analysis technique for analyzing the velocity histograms due to the high background light intensity. The axial mean velocity and turbulent intensity were uniform across the annulus under all operating conditions and the flow had little or no swirl component. The isothermal mean velocity was doubled by the burning of fuel, however, the isothermal turbulent intensity was relatively unaffected.

Zimmerman, D. R.↗
NASA NTRS1980

Transmission in flow ducts with peripherally varying linings

A finite element Galerkin formulation is used for the calculation of acoustical modes in uniform ducts with arbitrary geometry, mean flow and lining configuration. Hermitian 'non-conforming' sub-parametric elements are used and the dimensionality of the resulting eigenmatrix is reduced by the use of a condensation scheme based on the compatible eigenvectors in the case with no mean flow. Results are presented for simple circular and rectangular configurations for which exact comparison results are readily calculable. Computer graphics routines required to interpret modal data are described and sample results shown.

Astley, R. J.↗
NASA NTRS1980

Dynamic decisions and work load in multitask supervisory control

A paradigm is developed for the problem of allocating in time a single resource to multiple simultaneous task demands which appear randomly, last for various periods, and offer varying rewards for service. Based upon a dynamic optimizing algorithm plus an estimator, and including response time and future discounting constraints, a model of the human decisionmaker is compared to experimental results for human subjects performing such a task at a computer-graphics terminal. Results indicate a reasonable fit, under various model parameters and task conditions, and suggest interesting hypotheses about the nature of human 'planning ahead' and mental work load.

Tulga, M. K.↗
NASA NTRS1980

Automated optical navigation with application to Galileo

This paper presents an overview of an automated optical navigation (AON) system, a lower-cost, faster, earth-based stepping stone to onboard systems. AON provides estimation (orbit determination) and maneuver subsystems which are automatically linked to provide the fast response required by the Galileo mission, AON's first user. A real-time interactive executive schedules the subsystems to run concurrently or sequentially and enables interactive computer-graphics displays designed to speed evaluation and certification of navigation solutions. A compact trajectory integrator provides a favorable combination of speed and accuracy. Resident on a low-cost minicomputer and coded primarily in HAL/S, the NASA standard language for flight software, AON approaches a prototype for autonomous onboard navigation systems of the future.

Klumpp, A. R.↗
NASA NTRS1981

Synthetic battery cycling

The use of interactive computer graphics is suggested as an aid in battery system development. Mathematical representations of simplistic but fully representative functions of many electrochemical concepts of current practical interest will permit battery level charge and discharge phenomena to be analyzed in a qualitative manner prior to the assembly and testing of actual hardware. This technique is a useful addition to the variety of tools available to the battery system designer as he bridges the gap between interesting single cell life test data and reliable energy storage subsystems.

Thaller, L. H.↗
NASA NTRS1980

Modelling of DNA-protein recognition

Computer model-building procedures using stereochemical principles together with theoretical energy calculations appear to be, at this stage, the most promising route toward the elucidation of DNA-protein binding schemes and recognition principles. A review of models and bonding principles is conducted and approaches to modeling are considered, taking into account possible di-hydrogen-bonding schemes between a peptide and a base (or a base pair) of a double-stranded nucleic acid in the major groove, aspects of computer graphic modeling, and a search for isogeometric helices. The energetics of recognition complexes is discussed and several models for peptide DNA recognition are presented.

Rein, R.↗
NASA NTRS1981

Numerical stability of an explicit finite difference scheme for the solution of transient conduction in composite media

A theoretical evaluation of the stability of an explicit finite difference solution of the transient temperature field in a composite medium is presented. The grid points of the field are assumed uniformly spaced, and media interfaces are either vertical or horizontal and pass through grid points. In addition, perfect contact between different media (infinite interfacial conductance) is assumed. A finite difference form of the conduction equation is not valid at media interfaces; therefore, heat balance forms are derived. These equations were subjected to stability analysis, and a computer graphics code was developed that permitted determination of a maximum time step for a given grid spacing.

Campbell, W.↗
NASA NTRS1982

User's guide for SKETCH

A user's guide for the computer program SKETCH is presented. The removal of hidden lines from images of solid objects is a problem in computer graphics which is solved by SKETCH.

Hedgley, D. R., Jr.↗
NASA NTRS1982

Application of a computerized vibroacoustic data bank for random vibration criteria development

A computerized data bank system was developed for utilization of large amounts of vibration and acoustic data to formulate component random vibration design and test criteria. This system consists of a computer, graphics tablets, and a dry silver hard copier which are all desk top type hardware and occupy minimal space. Currently, the data bank contains data from the Saturn 5 and Titan 3 flight and static test programs. The vibration and acoustic data are stored in the form of power spectral density and one third octave band plots over the frequency range from 20 to 2000 Hz. The data were stored by digitizing each spectral plot by tracing with the graphics tablet. The digitized data were statistically analyzed, and the resulting 97.5 percent confidence levels were stored on tape along with the appropriate structural parameters. Standard extrapolation procedures were programmed for prediction of component random vibration test criteria for new launch vehicle and payload configurations. A user's manual is included to guide potential users through the programs.

Ferebee, R. C.↗
NASA NTRS1981

The Montana experience

The development and capabilities of the Montana geodata system are discussed. The system is entirely dependent on the state's central data processing facility which serves all agencies and is therefore restricted to batch mode processing. The computer graphics equipment is briefly described along with its application to state lands and township mapping and the production of water quality interval maps.

Dundas, T. R.↗
NASA NTRS1982

Synthetic battery cycling techniques

Synthetic battery cycling makes use of the fast growing capability of computer graphics to illustrate some of the basic characteristics of operation of individual electrodes within an operating electrochemical cell. It can also simulate the operation of an entire string of cells that are used as the energy storage subsystem of a power system. The group of techniques that as a class have been referred to as Synthetic Battery Cycling is developed in part to try to bridge the gap of understanding that exists between single cell characteristics and battery system behavior.

Leibecki, H. F.↗
NASA NTRS1981

Synthetic battery cycling

The trend in energy storage is toward systems with high-voltage and high-power outputs. These conditions accentuate the cumulative effects of small differences in characteristics from cell to cell in any large multicell battery. These considerations are of particular concern with a number of emerging electrochemical concepts where convenient overcharge reactions do not exist. The use of interactive computer graphics is suggested as an aid in battery system development. Mathematical representations of simplistic but fully representative functions of many electrochemical concepts of current practical interest will permit battery-level charge and discharge phenomena to be analyzed in a qualitative manner prior to the assembly and testing of actual hardware. This technique will be a useful addition to the variety of tools available to the battery system designer as he bridges the gap between interesting single-cell life test data and reliable energy storage subsystems.

Thaller, L. H.↗
NASA NTRS1982

Synthetic battery cycling techniques

The group of techniques that as a class are referred to as synthetic battery cycling are described with reference to spacecraft battery systems. Synthetic battery cycling makes use of the capability of computer graphics to illustrate some of the basic characteristics of operation of individual electrodes within an operating electrochemical cell. It can also simulate the operation of an entire string of cells that are used as the energy storage subsystem of a power system.

Leibecki, H.↗
NASA NTRS1983

Analysis of pilot control strategy

Methods for nonintrusive identification of pilot control strategy and task execution dynamics are presented along with examples based on flight data. The specific analysis technique is Nonintrusive Parameter Identification Procedure (NIPIP), which is described in a companion user's guide (NASA CR-170398). Quantification of pilot control strategy and task execution dynamics is discussed in general terms followed by a more detailed description of how NIPIP can be applied. The examples are based on flight data obtained from the NASA F-8 digital fly by wire airplane. These examples involve various piloting tasks and control axes as well as a demonstration of how the dynamics of the aircraft itself are identified using NIPIP. Application of NIPIP to the AFTI/F-16 flight test program is discussed. Recommendations are made for flight test applications in general and refinement of NIPIP to include interactive computer graphics.

Heffley, R. K.↗
NASA NTRS1982

Introduction to the concepts of TELEDEMO and TELEDIMS

An introduction to the system concepts: TELEDEMO and TELEDIMS is provided. TELEDEMO is derived primarily from computer graphics and, via incorporation of sophisticated image data compression, enables effective low cost teleconferencing at data rates as low as 1K bit/second using dial-up phone lines. Combining TELEDEMO's powerful capabilities for the development of presentation material with microprocessor-based Information Management Systems (IMS) yields a truly all electronic IMS called TELEDIMS.

Rice, R. F.↗