National Advisory Committee for Aeronautics (NACA) - 22 Matching Results

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Determination of Flight Paths of an SBD-1 Airplane in Simulated Diving Attacks, Special Report

Description: An investigation has been made to determine the motions of and the flight paths describe by a Navy dive-bombing airplane in simulated diving attacks. The data necessary to evaluate these items, with the exception of the atmospheric wind data, were obtained from automatic recording instruments installed entirely within the airplane. The atmospheric wind data were obtained from the ground by the balloon-theodolite method. The results of typical dives at various dive angles are presented in the form of time histories of the motion of the airplane as well as flight paths calculated with respect to still air and with respect to the ground.
Date: March 1943
Creator: Johnson, Harold I.
Partner: UNT Libraries Government Documents Department

An investigation of aircraft heaters IX: measured and predicted performance of two exhaust gas-air heat exchangers and an apparatus for evaluating exhaust gas-air heat exchangers

Description: Report presenting laboratory testing to determine the thermal output and pressure drop characteristics of the Airesearch and Solar fluted-type exhaust gas-air heat exchangers. The apparatus used in these tests consisted of a natural gas furnace of 3,000,000 Btu per hour thermal capacity, a centrifugal blower, and a system of ducting and various measuring devices. Results regarding the method of analysis, the Airesearch heat exchanger tests, the solar heat exchanger tests, and a comparison of the two heat exchangers are provided.
Date: March 1943
Creator: Boelter, L. M. K.; Miller, M. A.; Sharp, W. H.; Morrin, E. H.; Iversen, H. W. & Mason, W. E.
Partner: UNT Libraries Government Documents Department

Investigation of the longitudinal stability at high speeds of a 1/5-scale model of a tailless pursuit airplane

Description: From Summary: "Tests of a tailless pursuit airplane model at the Ames Aeronautical Laboratory have shown that in conditions corresponding to level flight at a Mach number less than 0.7 and at an altitude under 35,000 feet, no serious compressibility effects occurred and that no sudden adverse diving moments were encountered up to a Mach number of 0.74, the maximum speed of the tests. However, there were indications that the elevons might lose their effectiveness for longitudinal control during a pull-out from a steep dive."
Date: March 1943
Creator: Laitone, Edmund V.
Partner: UNT Libraries Government Documents Department

Torsion of flanged members with cross sections restrained against warping

Description: The longitudinal stresses and the stiffness of flange members - I-beams, channels, and Z-bars - were investigated when these members were subjected to torque with constraint against cross-sectional warping. Measured angles of rotation agreed with corresponding calculated values in which the torsion bending factor of the cross section was involved; the agreement was better for the I-beam and the Z-bar than for the channel. Longitudinal stresses measured at the mid-span were found to agree with the calculated values that involved unit warping as well as the torsion-bending factors: the channel showed the greatest discrepancy between measured and calculated values. When commonly given expressions for rotations and maximum longitudinal stresses in a twisted I-beam were applied to the channel and to the Z-bar, values were obtained that were in reasonably good agreement with values obtained by the method of torsion-bending constant and unit warping.
Date: March 1, 1943
Creator: Hill, H N
Partner: UNT Libraries Government Documents Department

Turbulent flow between rotating cylinders

Description: The turbulent air flow between rotating cylinders was investigated. The distributions of mean speed and of turbulence were measured in the gap between a rotating inner and a stationary outer cylinder. The measurements led to the conclusion that the turbulent flow in the gap cannot be considered two dimensional, but that a particular type of secondary motion takes place. It is shown that the experimentally found velocity distribution can be fully understood under the assumption that this secondary motion consists of three-dimensional ring-shape vortices. The vortices occur only in pairs, and their number and size depend on the speed of the rotating cylinder; the number was found to decrease with increasing speed. The secondary motion has an essential part in the transmission of the moment of momentum. In regions where the secondary motion is negligible, the momentum transfer follows the laws known for homologous turbulence. Ring-shape vortices are known to occur in the laminar flow between rotating cylinders, but it was hitherto unknown that they exist even at speeds that are several hundred times the critical limit.
Date: March 1, 1943
Creator: Shih-I, Pai
Partner: UNT Libraries Government Documents Department

XC-35 gust research project: Preliminary analysis of the lateral distribution of gust velocity along the span of an airplane

Description: Report presenting measurements of the lateral distribution of effective gust velocity along the span of the XC-35 airplane in a variety of weather conditions. Six standard shapes were determined from the distributions: triangular, rectangular, first trapezoidal, second trapezoidal, unsymmetrical, and double triangular.
Date: March 1943
Creator: Moskovitz, A. I.
Partner: UNT Libraries Government Documents Department