The Kosenbluth-Ferraro-Dungey sheath
Rosenbluth-Ferraro-Dungey sheath model of interaction between cold collisionless plasma and vacuum magnetic field
Buffalano, C.↗
SEARCH · Engineering Papers
Results for “interactive model”
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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Discussion of paper by J. L. Blank and W. R. Sill, 'Response of the moon to the time- varying interplanetary magnetic field.'
Critique of magnetic response model for interaction of moon and interplanetary plasma magnetic field proposed by Blank and Sill
Fuller, B. D.↗
The role of the nervous system in the organization and integration of living systems
Neurophysiological model for interactions between nervous system, cellular mechanisms, and human behavior synthesis
Source record↗
Study of cosmic ray motion in cosmic space near the earth
Data are presented on experimental installations developed in the cosmic ray variations laboratory in Kazgu (Alma-Ata). Various experiments on modelling the interaction of plasma with the geomagnetic field as well as the plasma distribution in quiet and disturbed fields are described. The characteristics of the meson supertelescope using scintillators (effective area, 10 sq m) for vertical alignments designed to study microvariations of the cosmic rays and their interrelation with magnetospheric fluctuations and the study of solar wind parameters are given.
Budilov, V. K.↗
Use of computer modeling to investigate a dynamic interaction problem in the Skylab TACS quad-valve package
A valve opening-response problem encountered during development of a control valve for the Skylab thruster attitude control system (TACS) is described. The problem involved effects of dynamic interaction among valves in the quad-redundant valve package. Also described is a detailed computer simulation of the quad-valve package which was helpful in resolving the problem.
Hesser, R. J.↗
Cryogenic wind tunnels: Unique capabilities for the aerodynamicist
The cryogenic wind-tunnel concept as a practical means for improving ground simulation of transonic flight conditions. The Langley 1/3-meter transonic cryogenic tunnel is operational, and the design of a cryogenic National Transonic Facility is undertaken. A review of some of the unique capabilities of cryogenic wind tunnels is presented. In particular, the advantages of having independent control of tunnel Mach number, total pressure, and total temperature are highlighted. This separate control over the three tunnel parameters will open new frontiers in Mach number, Reynolds number, aeroelastic, and model-tunnel interaction studies.
Hall, R. M.↗
Alternative strategies for implementing silicon-ribbon technology for photovoltaic applications
Interactive computer models are being designed to support the development of technological and economic data required to define the potential of silicon sheet growth for large scale photovoltaic applications. Technology projection and sensitivity analysis suggest that single-ribbon growth systems offer the best potential for achieving low-cost silicon sheet material within the shortest period of time. Such systems must be highly reliable, be capable of near unattended growth, and feature automatic melt replenishment. Processing-technology improvement, such as the following, are the key elements for reducing the cost of silicon sheet material: (i) increasing ribbon width; (ii) speeding up the growth rate; and (iii) decreasing ribbon thickness. Such tasks should be pursued in that order to minimize sheet material cost. One interesting finding is that significant reductions in sheet material cost are achievable in the near future by increasing ribbon width to 5 cm.
Kran, A.↗
Dynamic analysis of a class of mixed lumped-distributed parameter systems via numerical techniques
The modeling via transfer matrices of mixed lumped-distributed parameter systems with feedback control is discussed and novel methods of obtaining information on the controlled system's dynamic response via numerical methods is presented. These methods utilize numerical searches in the complex plane for the roots of the transcendental characteristic equation to determine the closed loop system eigenvalues. The fast Fourier transform (FFT) algorithm is utilized but in the inverse fashion (from frequency domain to time domain). The information obtained is identical to that contained in a model in modal coordinates, and can be used to construct such a model. An interactive computer program to do the required calculation is described, as well as its application to a manipulator arm design problem.
Book, W. J.↗
Software development: Stratosphere modeling
A more comprehensive model for stratospheric chemistry and transport theory was developed for the purpose of aiding predictions of changes in the stratospheric ozone content as a consequence of natural and anthropogenic processes. This new and more advanced stratospheric model is time dependent and the dependent variables are zonal means of the relevant meteorological quantities which are functions of latitude and height. The model was constructed by the best mathematical approach on a large IBM S360 in American National Standard FORTRAN. It will be both a scientific tool and an assessment device used to evaluate other models. The interactions of dynamics, photochemistry and radiation in the stratosphere can be governed by a set of fundamental dynamical equations.
Chen, H. C.↗
Displacement thickness distributions in transonic flows about 3-D wings
The transonic 3-D inviscid small-perturbation solution of Bailey and Ballhaus is combined with a finite-difference solution for Prandtl's boundary-layer equations in order to include viscous effects. The inviscid-viscous interaction is modeled by means of the displacement surface, which can be thought of as the effective body surface seen by the inviscid flow. Displacement thickness, lift, and pressure distributions resulting from the combined solution are presented for transonic flows about the RAE 101 A wing and a Lockheed transport wing, both at small angles of attack. The influence of changing arbitrarily the start of transition on the displacement surface and lift is discussed for the RAE wing flow.
Kordulla, W.↗
Transmission of sound through high subsonic flows in non-uniform ducts
The transmission of sound through a near-sonic throat in a variable area duct is studied using the method of matched asymptotic expansions applied to a quasi-one-dimensional model. Nonlinear interactions between the mean flow and the acoustic perturbation in the throat region are shown to cause significant effects on the sound field upstream and downstream of the throat. Numerical results are presented for several special applications of the general nonlinear theory.
Myers, M. K.↗
Computation of turbulent near wake for asymmetric airfoils
A numerical procedure for studying the turbulent near wake of two dimensional airfoil sections is presented. The Reynolds Navier-Stokes equations were written for flow about bodies of arbitrary geometry and solved on an arbitrary nonuniform curvilinear computational mesh. Eddy viscosity and Reynolds stress turbulence transport models are considered. Specific examples are shown for airfoil section by using an algebraic viscosity model with streamwise relaxation and the interactive Reynolds stress model.
Deiwert, G. S.↗
Temperature and velocity measurements in premixed turbulent flames
Turbulent flame speed data for premixed flames of methane-air, propane-air and ethylene-air mixtures stabilized in grid turbulence are reported and discussed. It is shown that turbulence effects on flame speed cannot be fully correlated by the turbulence length scale and r.m.s. velocity in the cold flow. Rather there appear to be significant flame-flow-turbulence interactions affecting both turbulence level in the reaction zone and measured flame speeds. Results of detailed velocity measurements, including autocorrelations, by laser velocimetry are used to elucidate the nature of these interactions. It is concluded that flame speed experiments must be designed and conducted to provide sufficient information (e.g., boundary conditions) to allow for reconstruction of the flow field and these interactions by modelers if the data are to be of value in turbulent combustion model development and evaluation.
Dandekar, K. V.↗
Electrohydrodynamic (EHD) stimulation of jet breakup
Electrohydrodynamic (EHD) excitation of liquid jets offers an alternative to piezoelectric excitation without the complex frequency response caused by piezoelectric and mechanical resonances. In an EHD exciter, an electrode near the nozzle applies an alternating Coulomb force to the jet surface, generating a disturbance which grows until a drop breaks off downstream. This interaction is modelled quite well by a linear, long wave model of the jet together with a cylindrical electric field. The breakup length, measured on a 33 micrometer jet, agrees quite well with that predicted by the theory, and increases with the square of the applied voltage, as expected. In addition, the frequency response is very smooth, with pronounced nulls occurring only at frequencies related to the time which the jet spends inside the exciter.
Crowley, J. M.↗
An investigation of MAGSAT and complementary data emphasizing precambrian shields and adjacent areas of West Africa and South America
The problems associated with the use of an interactive magnetic modeling program are reported and a publication summarizing the MAGSAT anomaly results for Africa and the possible tectonic associations of these anomalies is provided. An overview of the MAGSAT scalar anomaly map for Africa suggested a correlation of MAGSAT anomalies with major crustal blocks of uplift or depression and different degrees of regional metamorphism. The strongest MAGSAT anomalies in Africa are closely correlated spatially with major tectonic features. Results indicate that the Bangui anomaly may be caused by a central old Precambrian shield, flanked to the north and south by two relatively young sedimentary basins.
Hastings, D. A.↗
Planetary magnetospheres - The in situ astrophysical laboratories
Descriptions of the behavior, mechanisms, and effects of the magnetospheres of the inner six planets of the solar system are presented. The components of the earth's magnetosphere are detailed, including mention of the field-aligned current connecting the ionosphere of the earth to the magnetosphere, which is a situation in which a current travels along a magnetic field line. Similarities and differences are noted for known aspects of the magnetospheres of Venus, Mars, and Mercury, with the solar wind-planet interactions being modeled by gas dynamic calculations. Particular attention is given to the Jupiter magnetosphere as analog for the magnetospheres of astrophysical objects. Voyager 1 and 2 data are cited for evidence of upstream ion increases originating from the Jovian magnetosphere. Finally, the mechanisms of the Io plasma torus are examined.
Krimigis, S. M.↗
Quadrennial International Ozone Symposium, Boulder, CO, August 4-9, 1980, Proceedings. Volumes 1 & 2
Recent developments in observational techniques are examined, taking into account a review of some unresolved problems in the measurement/estimation of total ozone and the vertical ozone profile, the sensitivity of Dobson total ozone estimations to wavelength band calibration uncertainties, errors in Dobson total measurements arising from aerosol attenuation, and optical stop and focussing effects in the Dobson instrument. Other subjects considered are related to total ozone observations, tropospheric ozone, upper air ozone observations, observations of trace gases in the atmosphere, ozone photochemistry and directly related photochemical models, the interaction of ozone and atmospheric circulation, ozone effects on climate, and solar activity and ozone variations. Programs and recommendations involving ozone theory and observations are also discussed, giving attention to current problems of ozone chemistry, the upper atmosphere research satellite program, a French contribution to ozone related studies, and ozone and the middle atmosphere program.
London, J.↗
A simulation study of crew performance in operating an advanced transport aircraft in an automated terminal area environment
A simulation study assessing crew performance operating an advanced transport aircraft in an automated terminal area environment is described. The linking together of the Langley Advanced Transport Operating Systems Aft Flight Deck Simulator with the Terminal Area Air Traffic Model Simulation was required. The realism of an air traffic control (ATC) environment with audio controller instructions for the flight crews and the capability of inserting a live aircraft into the terminal area model to interact with computer generated aircraft was provided. Crew performance using the advanced displays and two separate control systems (automatic and manual) in flying area navigation routes in the automated ATC environment was assessed. Although the crews did not perform as well using the manual control system, their performances were within acceptable operational limits with little increase in workload. The crews favored using the manual control system and felt they were more alert and aware of their environment when using it.
Houck, J. A.↗