167,956 research outputs found

    Grid spacing control with variation diminishing splines

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    Methods used to specify and control two and three dimensional grids on which numerical solutions of partial differential equations may be obtained were studied. While initially focusing on grid generation, the research will evolve into a consideration of the interaction of grid generation with the solution of a partial differential equation. The multisurface method of grid generation was used to continuously patch a grid onto an existing grid. In the resulting grid the elements of the Jacobian matrix must be continuous across the boundary between the original grid and the patched grid. Programs were written which accept as input the coordinates of the original grid and the desired new boundary, and then use the three-surface or four-surface version of the multisurface method to extend the original grid out to a new boundary

    Use of a transcendental approximation in transient conduction analysis

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    Variation method applied to transient thermal conductivity in semiinfinite slab with nonlinear boundary conditio

    Use of a transcendental approximation in transient conduction analysis

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    Boundary condition solution and transcendental approximation for transient heat conduction proble

    Study made of interaction between sound fields and structural vibrations

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    Study analyzes structural vibrations and the interactions between them and sound fields. It outlines a conceptual framework to analyze the vibrations of systems and their interactions, incorporating the results of earlier studies and establishing a unified basis for continuing research

    Advanced refractory alloy corrosion loop program Quarterly progress report, 15 Jul. - 15 Oct. 1970

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    Evaluation of T-111 refractory alloy Rankine system corrosion test loo

    Development of SCR Aircraft takeoff and landing procedures for community noise abatement and their impact on flight safety

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    Piloted simulator studies to determine takeoff and landing procedures for a supersonic cruise transport concept that result in predicted community noise levels which meet current Federal Aviation Administration (FAA) standards are discussed. The results indicate that with the use of advanced procedures, the subject simulated aircraft meets the FAA traded noise levels during takeoff and landing utilizing average flight crew skills. The advanced takeoff procedures developed involved violating three of the current Federal Aviation Regulations (FAR) noise test conditions. These were: (1) thrust cutbacks at altitudes below 214 meters (700 ft); (2) thrust cutback level below those presently allowed; and (3) configuration change, other than raising the landing gear. It was not necessary to violate any FAR noise test conditions during landing approach. It was determined that the advanced procedures developed do not compromise flight safety. Automation of some of the aircraft functions reduced pilot workload, and the development of a simple head-up display to assist in the takeoff flight mode proved to be adequate

    Advanced refractory alloy corrosion loop program Quarterly progress report, 15 Jan. 1970 - 15 Apr. 1970

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    Operation and evaluation of Rankine system corrosion test loop based on refractory alloy

    A simulator study for the development and evaluation of operating procedures on a supersonic cruise research transport to minimize airport-community noise

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    Piloted-simulator studies were conducted to determine takeoff and landing operating procedures for a supersonic cruise research transport concept that result in predicted noise levels which meet current Federal Aviation Administration (FAA) certification standards. With the use of standard FAA noise certification test procedures, the subject simulated aircraft did not meet the FAA traded-noise-level standards during takeoff and landing. However, with the use of advanced procedures, this aircraft meets the traded-noise-level standards for flight crews with average skills. The advanced takeoff procedures developed involved violating some of the current Federal Aviation Regulations (FAR), but it was not necessary to violate any FAR noise-test conditions during landing approach. Noise contours were also determined for some of the simulated takeoffs and landings in order to indicate the noise-reduction advantages of using operational procedures other than standard
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