11 research outputs found

    The Effect of Boundary-layer Control by Suction and Several High-lift Devices on the Longitudinal Aerodynamic Characteristics of a 47.5 Degree Sweptback Wing-fuselage Combination

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    An investigation has been made in the Langley full-scale tunnel of a 47.5 degree sweptback wing-fuselage combination equipped for boundary-layer control by suction. The wing aspect ratio was 3.5, the taper ratio was 0.5, and the airfoil sections normal to the quarter-chord line were NACA 64(sub 1)-A112. The wing configurations tested included the wing with various combinations of extensible leading-edge and split flaps. The effect of Reynolds number, suction-slot location and suction flow coefficient on the aerodynamic characteristics was determined for the model at zero yaw over a range of angle of attack

    Langley Full-Scale Tunnel Investigation of a 1/3-Scale Model of the Chance Vought XF5U-1 Airplane

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    The results of an investigation of a 1/3-scale model of the Chance Vought XF5U-1 airplane in the Langley full-scale tunnel are presented in this report. The maximum lift and stalling characteristics of several model configurations, the longitudinal stability characteristics of the model, and the effectiveness of the control surfaces were determined with the propellers removed. The propulsive characteristics, the effect of propeller operation on the lift, and the static thrust of the model propellers were determined at several propeller-blade angles. The results with the propellers removed showed that the maximum lift coefficient of the complete model configuration was only 0.97 was compared with the value of 1.31 for the model configuration in which the engine-air ducts and canopy are removed. The model with the propellers removed (normal center-of-gravity position) has a positive static margin, stick fixed, varying from 5 to 13 percent of the mean aerodynamic chord throughout the unstalled range of lift coefficients. The unit horizontal tail is sufficiently powerful to trim the airplane with the propellers removed throughout the unstalled range of lift coefficients. The peak propulsive efficiencies for beta = 20 degrees and beta = 30 degrees were increased 7 percent at C(sub L) congruent to 0.67 and 20 percent at C(sub L) congruent to 0.74, respectively, with the propellers rotating upward in the center than with the propellers rotating downward in the center. Indications are that the minimum forward-flight speed of the airplane for full-power operation at sea level will be about 90 miles per hour. Decreasing the weight and increasing the power reduced this value of minimum speed and there were no indications from the results of a lower limit to the minimum speed

    Transportation in a 100% renewable energy system

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    20 pages, 1 figure, 11 tables, 4 appendices.-- Corrigendum to Transportation in a 100% renewable energy system, Energy Conversion and Management 185: 891 (2019). https://doi.org/10.1016/j.enconman.2018.12.036A 100% renewable economy would give a lasting solution to the challenges raised by climate change, energy security, sustainability, and pollution. The conversion of the present transport system appears to be one of the most difficult aspects of such renewable transition. This study reviews the technologies and systems that are being proposed or proven as alternative to fossil-fuel based transportation, and their prospects for their entry into the post-carbon era, from both technological and energetic viewpoints. The energetic cost of the transition from the current transportation system into global 100% renewable transportation is estimated, as well as the electrical energy required for the operation of the new renewable transportation sector. A 100% renewable transport providing the same service as global transport in 2014 would demand about 18% less energy. The main reduction is expected in road transport (69%), but the shipping and air sectors would notably increase their consumptions: 163% and 149%, respectively. The analysis concludes that a 100% renewable transportation is feasible, but not necessarily compatible with indefinite increase of resources consumption. The major material and energy limitations and obstacles of each transport sector for this transition are shownThis study has been supported by the MEDEAS project (“Modeling the Renewable Energy Transition in Europe”), European Union’s Horizon 2020 research and innovation program, grant agreement No. 691287EU of the Framework Program for Research and Innovation actions, H2020 LCE-21-2015Peer Reviewe
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