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Results for “PENETRATION”

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 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Manual and automatic flight control during severe turbulence penetration

In this paper, updated pilot/display/aircraft analysis techniques are applied to the problem of turbulence upset. In the course of an investigation of standard operating procedures and current autopilot turbulence modes, it was found that an improved turbulence penetration system is needed. A simulation was conducted to evaluate the turbulence autopilot and flight director concepts. It was found that an energy management system comprising the integrated autopilot and thrust director provided the greatest decrease in pilot work load and improvement in performance.

Johnston, D. E.↗
NASA NTRS1976

Manual and automatic flight control during severe turbulence penetration

An analytical and experimental investigation of possible contributing factors in jet aircraft turbulence upsets was conducted. Major contributing factors identified included autopilot and display deficiencies, the large aircraft inertia and associated long response time, and excessive pilot workload. An integrated flight and thrust energy management director system was synthesized. The system was incorporated in a moving-base simulation and evaluated using highly experienced airline pilots. The evaluation included comparison of pilot workload and flight performance during severe turbulence penetration utilizing four control/display concepts: manual control with conventional full panel display, conventional autopilot (A/P-A) with conventional full panel display, improved autopilot (A/P-B) with conventional full panel display plus thrust director display, and longitudinal flight director with conventional full panel display plus thrust director display. Simulation results show improved performance, reduced pilot workload, and a pilot preference for the autopilot system controlling to the flight director command and manual control of thrust following the trim thrust director.

Johnston, D. E.↗
NASA NTRS1976

Basalt models for the Mars penetrator mission: Geology of the Amboy Lava Field, California

Amboy lava field (San Bernardino County, California) is a Holocene basalt flow selected as a test site for potential Mars Penetrators. A discussion is presented of (1) the general relations of basalt flow features and textures to styles of eruptions on earth, (2) the types of basalt flows likely to be encountered on Mars and the rationale for selection of the Amboy lava field as a test site, (3) the general geology of the Amboy lava field, and (4) detailed descriptions of the target sites at Amboy lava field.

Greeley, R.↗
NASA NTRS1977

Finite-element analysis of a weld-penetration problem

The stress concentration factor for a weld penetration defect is calculated by the finite-element method. A stress intensity factor is computed by use of the finite-element solution and the J-integral. The results are compared with experimental results.

Rogge, T. R.↗
NASA NTRS1979

Penetrating fire extinguisher

Fire extinguisher with replacable hard pointed tip is used to penetrate metal skins, wall panels, and other barriers and inject fire extinguishing chemicals.

Gray, N. C.↗
NASA NTRS1975

Building application of solar energy. Study no. 2: Representative buildings for solar energy performance analysis and market penetration

The following topics are discussed: (1) Assignment of population to microclimatic zones; (2) specifications of the mix of buildings in the SCE territory; (3) specification of four typical buildings for thermal analysis and market penetration studies; (4) identification of the materials and energy conserving characteristics of these typical buildings; (5) specifications of the HVAC functions used in each typical building, and determination of the HVAC systems used in each building; and (6) identification of the type of fuel used in each building.

Hirshberg, A. S.↗
NASA NTRS1979

Checking weld penetration

Fused wire in weld root area verifies weld penetration in electron-beam-welded joints. Method could be used in automotive, aircraft, and machinery manufacturing when electron-beam-welds cannot be inspected ultrasonically.

Macfarlane, D. I.↗
NASA NTRS1979

Building penetration analysis

The airborne exposure to carbon fibers experienced within a building may be substantially less than that outside the building. By their very nature, buildings provide a barrier to the free flow of airborne particulate contaminants through the air space they occupy. The objective of this report is an evaluation of the degree to which buildings and other structures will attenuate potential exposures to carbon fibers. Most if not all types of buildings, and all phenomena which may influence the extent to which fibers in outdoor air can penetrate structures are addressed.

Source record↗
NASA NTRS1979

Impulsive penetration and viscous interaction

How the magnetosheath plasma enters the entry layer and low latitude boundary layers, with the particle energy spectra almost unchanged is investigated. It was proposed by Lemaire that this is accomplished by impulsive penetration of plasma clouds of plasmoids. Once inside the magnetosphere, a plasmoid with its own momentum will polarize, to create its own electric field for continued motion. This voltage generator charges up the sides of the boundary layers, in the process creating the internal magnetospheric electric field. The entry layer particles will gradient and curvature drift, constituting still another generator, a current generator, to power magnetospheric plasma processes. This may be the explanation for the viscous interaction first proposed by Axford and Hines.

Heikkila, W. J.↗
NASA NTRS1980

Direct effects of lightning on an aircraft during intentional penetrations of thunderstorms

An armored T-28 aircraft was struck by lightning on two different days while participating in the 1979 severe environmental storm and mesoscale experiment in Oklahoma. The T-28, which is specially armored and instrumented, was making intentional penetrations of thunderstorms and was struck twice on 30 May and once on 5 June. Various degrees of damage, mainly in the form of large burn spots and holes, resulted to the aircraft.

Musil, D. J.↗
NASA NTRS1980

Energetic particle penetrations into the inner magnetosphere

The nose structures observed on 90-deg pitch angle ion spectrograms characteristic of energetic particle injection into the ring current region of the inner magnetosphere in the afternoon to midnight sector are examined in detail on the basis of Explorer 45 data. A statistical analysis of the time dependence of nose structures yields a highest probability of occurrence at around 2000 MLT, and most events are found to occur on successive passes. The appearance of nose events is also related to an enhancement or change in configuration of the geoelectric field which alters magnetospheric convection patterns to drive an ion front close to the earth, where it can be observed by Explorer 45. The observed characteristics of nose structures are interpreted in terms of adiabatic charged particle motions in the magnetosphere in a Volland-Stern convection electric field model, which is also applied to explain the energy spectra and dispersion in penetration distances of electrons and ions observed in the postmidnight to morning sectors.

Ejiri, M.↗
NASA NTRS1981

Electron penetration of spacecraft thermal insulation

The external thermal blanket with 13 mils of polyethylene which has the known range and stopping power as a function of electron energy is investiated. The most recent omnidirectional peak Jovian electron flux at 5 Jupiter radii is applied, the electron current penetrating the thermal blanket is calculated and allowed to impinge on a typical 20 mil polyethylene insulator surrounding a wire. The radiation dose rate to the insulator is then calculated and the electrical conductivity found. The results demonstrate that the increased electronic mobility is sufficient to keep the maximum induced electric field two orders of magnitude below the critical breakdown strength.

Powers, W. L.↗
NASA NTRS1982

High temperature penetrator assembly with bayonet plug and ramp-activated lock

A penetration apparatus, for very high temperature applications in which a base plug is inserted into an opening through a bulkhead is described. The base plug has a head shape and is seated against the highest temperature surface of the bulkhead, which may be the skin of the nose cone or other part of a space vehicle intended for nondestructive atmospheric reentry. From the second side of the bulkhead at which the less severe environment is extant, a bayonet plug is inserted into the base plug and engages an internal shoulder at about 90 deg rotation. The bayonet plug has an integral flanged portion and a pair of ramping washers which are located between the flange and the second bulkhead surface with a spacing washer as necessary.

Wood, K. E.↗
NASA NTRS1982

Nonlinear modal analysis of penetrative convection

It is pointed out that thermal convection in many astrophysical and geophysical settings occurs in an unstable layer bounded above and below by regions which are stably stratified. The convective motions may extend a substantial distance into the adjacent stable zones. If the motions have little direct effect upon the mean stratification of the stable zone, then they are usually referred to as convective overshooting. The primary objective of the present investigation is to study the dynamics of overshooting at very large Rayleigh numbers, mainly with stellar applications in mind. Numerically this is only feasible if severe simplifications are made in the description of what are likely to be turbulent motions. The approach employed in the investigation utilizes nonlinear modal equations in which the vertical and temporal structure of the convection is described accurately at the expense of the horizontal structure. A summary of the salient properties of penetrative convection is provided on the basis of the results of the conducted studies.

Zahn, J.-P.↗
NASA NTRS1983

Comments on some problems in computational penetration mechanics

Three problem areas in the computer simulation of large-scale penetration mechanics problems are briefly discussed. These are numerical instabilities due to incomplete integration of the momentum or continuity equations, constitutive modelling, and friction effects.

Oden, J. T.↗
NASA NTRS1984

Analysis of SIR-B radar illumination of geometry for depth of penetration and surface feature and vegetation detection, Nevada and California

The measurement capability provided by the Shuttle Imaging Radar (SIR-B) was used to determine: (1) the relationships between radar illumination geometry and depth of penetration in different climatic and physiographic environments in Nevada; and, (2) the relationships between radar illumination geometry and detection and analysis of structural features in different climatic and physiographic environments in Nevada.

Taranik, J. V.↗