National Advisory Committee for Aeronautics (NACA) - 420 Matching Results

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Addition of heat to a compressible fluid in motion

Description: From Introduction: "The purpose of this report is to summarize, without extended proofs, the results of a study of a simplified model of nonadiabiatic, compressible fluid flow, both subsonic and supersonic, and to state these results in a form that will make them immediately useful in providing a theoretical background for current technical problems of high-speed combustion.
Date: February 1945
Creator: Hicks, Bruce L
Partner: UNT Libraries Government Documents Department

Aerodynamic Characteristics of Four Republic Airfoil Sections from Tests in Langley Two-Dimensional Low-Turbulence Tunnels

Description: Four airfoils sections, designed by the Republic Aviation Corporation for the root and tip sections of the XF-12 airplane, were tested in the Langley two-dimensional low-turbulence tunnels to obtain their aerodynamic characteristics. Lift characteristics were obtained at Reynolds numbers of 3,000,000, 6,000,000, 9,000,000, and 14,000,000, whereas drag characteristics were obtained at Reynolds numbers of 3,000,000, 6,000,000, and 9,000,000. Pressure distributions were obtained for one of the root sections for several angles of attack at a Reynolds number of 2,600,000. Comparison of the root section that appeared best from the tests with the corresponding NACA 65-series section shows the Republic section has a higher maximum lift and higher calculated critical speeds, but a higher minimum drag. In addition, with standard roughness applied to the leading edge, the maximum lift of the Republic airfoil is lower than that of the NACA airfoil. Comparison of the Republic tip section with the corresponding NACA 65-series section shows the Republic airfoil has a lower maximum lift and a higher minimum drag than the NACA airfoil. The calculated critical speeds of the Republic section are slightly higher than those of the NACA section.
Date: September 27, 1945
Creator: Klein, Milton M.
Partner: UNT Libraries Government Documents Department

Air-flow and performance characteristics of the engine-stage supercharger of a double-row radial aircraft engine I: effect of operating variables

Description: From Introduction: "The tests reported herein, conducted during the early part of 1945, were made to determine the inherent charge-air distribution characteristics of the engine-stage supercharger of the double-row radial engine."
Date: August 1945
Creator: Mesrobian, John M.
Partner: UNT Libraries Government Documents Department

Airspeed fluctuations as a measure of atmospheric turbulence

Description: From Introduction: "Increments in structural loads due to atmospheric turbulence can be accurately expressed in terms of flight speed and effective gust velocities (reference 4). Data from which the effective gust velocities could be computed were also obtained during the flights of the XC-35 airplane. These data have been used to determine the significance of the fluctuations in the pilot's indicated-airspeed readings in relation to structural loads to due to atmospheric turbulence."
Date: July 1945
Creator: Tolefson, H B
Partner: UNT Libraries Government Documents Department

Analysis and modification of theory for impact of seaplanes on water

Description: From Summary: "An analysis of available theory on seaplane impact and a proposed modification thereto are presented. In previous methods the overall momentum of the float and virtual mass has been assumed to remain constant during the impact but the present analysis shows that this assumption is rigorously correct only when the resultant velocity of the float is normal to the keel."
Date: August 20, 1945
Creator: Mayo, Wilbur L.
Partner: UNT Libraries Government Documents Department

An analysis of jet-propulsion systems making direct use of the working substance of a thermodynamic cycle

Description: From Summary: "The results of the analysis showed that the combined efficiency, which is unacceptably low at speeds less than 300 miles per hour, becomes nearly equal to that of conventional power plants of current design at 500 miles per hour. It was also shown that the efficiency will be increased considerably as the physical limitations on cycle temperature and blower speed are raised and as the efficiencies of the system components are improved."
Date: February 1945
Creator: Rubert, Kennedy F
Partner: UNT Libraries Government Documents Department

An analysis of life expectancy of airplane wings in normal cruising flight

Description: From Summary: "In order to provide a basis for judging the relative importance of wing failure by fatigue and by single intense gusts, an analysis of wing life for normal cruising flight was made based on data on the frequency of atmospheric gusts. The independent variables considered in the analysis included stress-concentration factor, stress-load relation, wing loading, design and cruising speeds, design gust velocity, and airplane size. Several methods for estimating fatigue life from gust frequencies are discussed."
Date: January 1, 1945
Creator: Putnam, Abbott A
Partner: UNT Libraries Government Documents Department

An analysis of life expectancy of airplane wings in normal cruising flight

Description: From Summary: "The independent variables considered in the analysis included stress-concentration factor, stress-load relation, wing loading, design and cruising speeds, design gust velocity, and airplane size. Several methods for estimating fatigue life from gust frequencies are discussed."
Date: July 1945
Creator: Putnam, Abbott A
Partner: UNT Libraries Government Documents Department

An analysis of the dissipation of heat in conditions of icing from a section of the wing of the C-46 airplane

Description: From Introduction: "The performance of the heated wing of the C-46 airplane (reference 1), in conditions of icing, has been analyzed. The method of calculating the dissipation of heat, both by convection and by evaporation, from a heated surface exposed to conditions of icing is given in reference 2."
Date: 1945?~
Creator: Hardy, J K
Partner: UNT Libraries Government Documents Department

Analysis of V-G records from the SNJ-4 airplane

Description: Report discusses an attempt to adapt a method of analysis of V-G data to predict the occurrences of large values of airspeed and acceleration from an SNJ-4 airplane; the data are presented as "flight envelopes". The flight envelopes "predict that, on average, in a stated number of flight hours, one airspeed, one positive acceleration, and one negative acceleration will exceed the envelope with equal probability of the accelerations being experienced at any airspeed" (from Discussion). The analysis method shows promise for predicting flight loads and speeds for airplanes on which loads due to maneuvers predominate.
Date: December 1945
Creator: Wilkerson, M. & Bennett, S. A.
Partner: UNT Libraries Government Documents Department

Analytical study of transmission of load from skin to stiffeners and rings of pressurized cabin structure

Description: From Introduction: "The investigations in this paper were made to obtain more generalized mathematical analyses of monocoque structure subjected to internal pressure. It is also assumed that the principle of superposition can be applied, so that stress analysis of a structure with combined internal pressure and external load can be made without excessive complication."
Date: October 1945
Creator: Pian, Theodore Hsueh-Huang
Partner: UNT Libraries Government Documents Department

Application of a numerical procedure to stress analysis of stringer-reinforced panels

Description: From Introduction: "In the present paper a numerical procedure for the stress analysis of flat-sheet and stringer combinations of arbitrary construction and loading is presented and applied to axially loaded panels and to the reinforced covers of box beams."
Date: March 1945
Creator: Kempner, Joseph
Partner: UNT Libraries Government Documents Department

An approximate determination of the power required to move control surfaces as related to control-booster design

Description: From Summary: "As a part of a general investigation of control boosters, preliminary calculations were made to indicate the sizes of control boosters necessary to move the controls of airplanes of various sizes. The analysis was based on the assumption that the controls were moved with a rapidity and amplitude equal to that measured with a fighter airplane in simulated combat. A corollary purpose consisted in determining the effect on reducing booster-power unit size of incorporating an energy accumulator in the booster system."
Date: September 1945
Creator: Johnson, Harold I.
Partner: UNT Libraries Government Documents Department

Attainment of a straight-line trajectory for a preset guided missile with special reference to effect of wind or target motion

Description: Report discusses the results of a study "of the requirements for the attainment of a straight-line trajectory for a preset guided missile in the presence of wind or target motion" (from Summary). Information about the straight-line trajectory, position of the launching airplane, straight-line collision course, and arrangement of the autopilot in the missile is provided. Recommendations are also made about the creation of a bombsight mounting for the pilot of the launching airplane in order to attain the desired straight-line collision course.
Date: August 1945
Creator: Ribner, Herbert S.
Partner: UNT Libraries Government Documents Department

Axial fatigue test at two stress amplitudes of 0.032-inch 24S-T sheet specimens with a circular hole

Description: Report presenting testing of the effect of applying a number of cycles of a high fatigue stress followed by a number of cycles of relatively low stress to failure has been investigated on 93 drilled specimens of a 24S-T sheet. The results indicated that any general formula for endurance must take sequence into consideration, which makes overly simple formulas inadequate to describe endurance over varying stress amplitudes.
Date: July 1945
Creator: Brueggeman, W. C.; Mayer, M., Jr. & Smith, W. H.
Partner: UNT Libraries Government Documents Department

Bearing strengths of 24S-T aluminum alloy plate

Description: Report presenting a series of tests to determine the bearing yield and ultimate strengths of samples of 1/4- and 2-inch-thick plate of aluminum alloy 24S-T and to establish nominal ratios of bearing-to-tensile properties for the commercial range of plate thicknesses. Results regarding individual bearing testing, ratios of average bearing to tensile properties, and ratios of bearing yield strength to tensile yield strength are provided.
Date: June 1945
Creator: Moore, R. L. & Wescoat, C.
Partner: UNT Libraries Government Documents Department

Bearing strengths of 75S-T aluminum-alloy sheet and extruded angle

Description: Report presenting an investigation to determine the bearing yield and ultimate strengths of 75S-T alloy in sheet form in both with- and across-grain directions and extruded angle in the longitudinal direction. Ratios of bearing to tensile properties were also determined.
Date: February 1945
Creator: Wescoat, C. & Moore, R. L.
Partner: UNT Libraries Government Documents Department

Bending and shear stresses developed by the instantaneous arrest of the root of a cantilever beam rotating with constant angular velocity about a transverse axis through the root

Description: From Summary: "A theoretical investigation was made of the behavior of a cantilever beam in rotational motion about a transverse axis through the root determining the stresses, the deflections, and the accelerations that occur in the beam as a result of the arrest of motion. The equations for bending and shear stress reveal that, at a given percentage of the distance from root to tip and at a given trip velocity, the bending stresses for a particular mode are independent of the length of the beam and the shear stresses vary inversely with the length. When examined with respect to a given angular velocity instead of a given tip velocity, the equations reveal that the bending stress is proportional to the length of the beam whereas the shear stress is independent of the length."
Date: June 1945
Creator: Stowell, Elbridge Z.; Schwartz, Edward B. & Houbolt, John C.
Partner: UNT Libraries Government Documents Department

Bending-torsion flutter calculations modified by subsonic compressibility corrections

Description: From Summary: "A number of calculations of bending-torsion wing flutter are made at two Mach numbers, m=0 (incompressible case) and m=0.7, and results are compared. The air forces employed for the case of m=0.7 are based on Frazer's recalculation of Possio's results, which are derived on the assumption of small disturbances to the main flow. For ordinary wings of normal density and of low bending frequency in comparison with torsion frequency, the compressibility correction to the flutter speed appears to be of the order of a few percent; whereas the correction to flutter speed for high-density wing sections, such as propeller sections, and to the wing-divergence speed in general, may be based on a rule using the (1 - m(2))1/4 factor and, for m=0.7, represents a decrease of the order of 17 percent."
Date: December 18, 1945
Creator: Garrick, I. E.
Partner: UNT Libraries Government Documents Department