21,877 research outputs found

    Use of optimization to predict the effect of selected parameters on commuter aircraft performance

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    The relationships between field length and cruise speed and aircraft direct operating cost were determined. A gradient optimizing computer program was developed to minimize direct operating cost (DOC) as a function of airplane geometry. In this way, the best airplane operating under one set of constraints can be compared with the best operating under another. A constant 30-passenger fuselage and rubberized engines based on the General Electric CT-7 were used as a baseline. All aircraft had to have a 600 nautical mile maximum range and were designed to FAR part 25 structural integrity and climb gradient regulations. Direct operating cost was minimized for a typical design mission of 150 nautical miles. For purposes of C sub L sub max calculation, all aircraft had double-slotted flaps but with no Fowler action

    Use of optimization to predict the effect of selected parameters on commuter aircraft performance

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    An optimizing computer program determined the turboprop aircraft with lowest direct operating cost for various sets of cruise speed and field length constraints. External variables included wing area, wing aspect ratio and engine sea level static horsepower; tail sizes, climb speed and cruise altitude were varied within the function evaluation program. Direct operating cost was minimized for a 150 n.mi typical mission. Generally, DOC increased with increasing speed and decreasing field length but not by a large amount. Ride roughness, however, increased considerably as speed became higher and field length became shorter

    Electric-arc heater Patent

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    Magnetically diffused radial electric arc heate

    Orbital surveys and state resource management

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    The resource management implications of satellite earth resource surveys for the state of Ohio are discussed. Discussions cover environmental problems, planning future developments, and short- and long-range benefits of such resource management

    A magnetically rotated electric arc air heater employing a strong magnetic field and copper electrodes

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    Magnetically rotated electric arc air heater using strong magnetic field and copper electrode

    The Envelope of Holomorphy of a Two-Manifold in C2

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    Paper by L. R. Hunt and R. O. Wells, Jr

    A study of possible sea state information in the sample and hold gate statistics for the GEOS-3 satellite altimeter

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    The statistical variations in the sample gate outputs of the GEOS-3 satellite altimeter were studied for possible sea state information. After examination of a large number of statistical characteristics of the altimeter waveforms, it was found that the best sea predictor for H-1/3 in the range of 0 to 3 meters was the 75th percentile of sample and hold gate number 11

    Solar radiation observation stations with complete listing of data archived by the National Climatic Center, Asheville, North Carolina and initial listing of data not currently archived

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    A listing is provided of organizations taking solar radiation data, the 166 stations where observations are made, the type of equipment used, the form of the recorded data, and the period of operation of each station. Included is a listing of the data from 150 solar radiation stations collected over the past 25 years and stored by the National Climatic Center

    An experimental study of the temporal statistics of radio signals scattered by rain

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    A fixed-beam bistatic CW experiment designed to measure the temporal statistics of the volume reflectivity produced by hydrometeors at several selected altitudes, scattering angles, and at two frequencies (3.6 and 7.8 GHz) is described. Surface rain gauge data, local meteorological data, surveillance S-band radar, and great-circle path propagation measurements were also made to describe the general weather and propagation conditions and to distinguish precipitation scatter signals from those caused by ducting and other nonhydrometeor scatter mechanisms. The data analysis procedures were designed to provide an assessment of a one-year sample of data with a time resolution of one minute. The cumulative distributions of the bistatic signals for all of the rainy minutes during this period are presented for the several path geometries
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