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Two-Dimensional Irrotational Transonic Flows of a Compressible Fluid

Description: The methods of NACA TN No. 995 have been slightly modified and extended in include flows with circulation by considering the alteration of the singularities of the incompressible solution due to the presence of the hypergeometric functions in the analytic continuation of the solution. It was found that for finite Mach numbers the only case in which the nature of the singularity can remain unchanged is for a ratio of specific heats equal to -1. From a study of two particular flows it seems that … more
Date: June 1948
Creator: Kuo, Yung-Huai
Partner: UNT Libraries Government Documents Department
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Tables and charts of flow parameters across oblique shocks

Description: Shock-wave equations have been evaluated for a range of Mach number in front of the shock from 1.05 to 4.0. Mach number behind the shock, pressure ratio, derivation of flow, and angle of shock are presented on charts. Values are also included for density ratio and change in entropy.
Date: August 1948
Creator: Neice, Mary M.
Partner: UNT Libraries Government Documents Department
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Lifting-Surface-Theory Aspect-Ratio Corrections to the Lift and Hinge-Moment Parameters for Full-Span Elevators on Horizontal Tail Surfaces

Description: "A limited number of lifting-surface-theory solutions for wings with chordwise loadings resulting from angle of attack, parabolic-arc camber, and flap deflection are now available. These solutions were studied with the purpose of determining methods of extrapolating the results in such a way that they could be used to determine lifting-surface-theory values of the aspect-ratio corrections to the lift and hinge-moment parameters for both angle-of-attack and flap-deflection-type loading that coul… more
Date: 1948
Creator: Swanson, Robert S. & Crandall, Stewart M.
Partner: UNT Libraries Government Documents Department
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A Generalized Theoretical Investigation of the Hydrodynamic Pitching Moments Experienced by V-Bottom Seaplanes During Step-Landing Impacts and Comparisons With Experiment

Description: Note presenting a theoretical investigation made of the hydrodynamic pitching moments experienced by V-bottom seaplanes during step-landing impacts. The entire immersion process is analyzed from the instant of initial contact until the seaplane rebounds from the water surface.
Date: June 1948
Creator: Milwitzky, Benjamin
Partner: UNT Libraries Government Documents Department
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An analysis of the airspeeds and normal accelerations of Boeing B-247 and B-247D airplanes in commercial transport operation

Description: From Introduction: "The results of analyses of V-G data given in references 1 to 5 have shown that the flight loads of airplanes operated in commercial transport service are influenced by operating speeds and by forecasting and dispatching practices as reflected in differences between operations during the prewar and wartime periods. The available data are summarized and the flight results are compared with the results of analyses made in references 1 to 5."
Date: December 1948
Creator: Walker, Walter G. & Hadlock, Ivan K.
Partner: UNT Libraries Government Documents Department
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Friction Coefficients in the Inlet Length of Smooth Round Tubes

Description: Note presenting an experimental study of friction coefficients near the inlet of smooth, round tubes with bellmouth entrances. Four different combinations of approach section and bellmouth entry were used. Results regarding the apparent local friction coefficient, integrated friction coefficient, effect of induced turbulence, laminar inlet zone, developed friction coefficient, and application to discharge coefficients for rounded-entrance flow nozzles are provided.
Date: November 1948
Creator: Shapiro, Ascher H. & Smith, R. Douglas
Partner: UNT Libraries Government Documents Department
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Recommendations for numerical solution of reinforced-panel and fuselage-ring problems

Description: Report presenting procedures for solving the equations of equilibrium of reinforced panels and isolated fuselage rings as represented by the external loads and operations table established according to Southwell's method. By using these equations, the stress distribution can be easily determined.
Date: December 1948
Creator: Hoff, N. J. & Libby, Paul A.
Partner: UNT Libraries Government Documents Department
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Effect of Variables in Welding Technique on the Strength of Direct-Current Metal-Arc-Welded Joints in Aircraft Steel 2 - Repeated-Stress Tests of Joints in SAE 4130 Seamless Steel Tubing

Description: "A series of tests were made for the purposes of establishing the effects of several variables in welding technique on the fatigue strength of arc-welded joints in SAE 4130 seamless steel tubing. The variables included type of electrode, speed of welding, current, position, amount of preheat, and other factors which in turn controlled the weld contour, penetration, and depth of the heat-affected zone. A range of joint design was also investigated" (p. 1).
Date: April 1948
Creator: Voldrich, C. B. & Armstrong, E. T.
Partner: UNT Libraries Government Documents Department
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Theoretical comparison of several methods of thrust augmentation for turbojet engines

Description: "A theoretical investigation of tail-pipe burning, water injection at the compressor inlet, combination tail-pipe burning plus water injection, bleedoff, and rocket-assist methods thrust augmentation for turbojet engines was made for an engine representative of those in current use. The effect of augmented liquid ratio on augmented thrust ratio and the effects of altitude and flight Mach number on the performance of various methods were determined. The additional take-off weight involved by the… more
Date: October 27, 1948
Creator: Hall, Eldon W. & Wilcox, E. Clinton
Partner: UNT Libraries Government Documents Department
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Axial fatigue tests at zero mean stress of 24S-T and 75S-T aluminum-alloy strips with a central circular hole

Description: From Summary: "Axial fatigue tests at zero mean stress have been made on 0.032- and 0.064-inch 24S-T and 0.032-inch 75S-T sheet-metal specimens 1/4, 1/2, 1, and 2 inches wide without a hole and with central holes giving a range of hole diameter D to specimen width W from 0.01 to 0.95. No systematic difference was noted between the results for the 0.032-inch and the 0.064-inch specimens although the latter seemed the more consistent. In general the fatigue strength based on the minimum section d… more
Date: August 1948
Creator: Brueggeman, W. C. & Mayer, M., Jr.
Partner: UNT Libraries Government Documents Department
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Collection of Test Data for Lateral Control With Full-Span Flaps

Description: Report presenting a collection of available test data on lateral control with full-span flaps. Internal-control effectiveness and hinge-moment data were obtained from two-dimensional, three-dimensional, and flight tests. Results regarding slot-lip and flap-trailing-edge ailerons, spoiler-type ailerons other than slot-lip ailerons, ailerons with retractable-type flaps, and application of data to specific airplane design are provided.
Date: April 1948
Creator: Fischel, Jack & Ivey, Margaret F.
Partner: UNT Libraries Government Documents Department
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Characteristics of thin triangular wings with constant-chord partial-span control surfaces at supersonic speeds

Description: Report presenting a theoretical analysis of the characteristics of constant-chord partial-span control surfaces on thin triangular wings at supersonic speeds by use of methods based on the linearized theory for supersonic flow. Two cases were treated with the analysis. Results regarding lift coefficient, rolling-moment coefficient, and hinge-moment coefficient due to flap deflection, hinge-moment coefficient due to angle of attack, and the pitching-moment coefficient due to flap lift.
Date: July 1948
Creator: Tucker, Warren A. & Nelson, Robert L.
Partner: UNT Libraries Government Documents Department
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Aerodynamic Properties of Slender Wing-Body Combinations at Subsonic, Transonic, and Supersonic Speeds

Description: From Introduction: "In an incomprehensible medium, the mutual interference of a fuselage and wing of high-aspect ratio (to which lifting-line theory is applicable) has been treated by Lennertz, Wiselsberger, Pepper, and Multhopp in reference 1, 2, 3, and 4. It is the purpose of this note to treat the effect of on the aerodynamic loading of the mutual interference between a low-aspect-ratio pointed wing and a fuselage consisting of a slender body of revolution."
Date: July 1948
Creator: Spreiter, John R.
Partner: UNT Libraries Government Documents Department
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Wing-tunnel investigation of effects of forward movements of transition on section characteristics of a low-drag airfoil with a 0.24-chord sealed plain aileron

Description: Report presenting an investigation to determine the effects of forward movements of transition on the section characteristics of a 12-percent-thick low-drag airfoil section with a 0.24-chord sealed plain aileron. Section lift and aileron section hinge-moment and seal-pressure characteristics were determined at a specific Reynolds number for aerodynamically smooth surfaces and with fixed transition at two different points.
Date: May 1948
Creator: Racisz, Stanley F. & Cahill, Jones F.
Partner: UNT Libraries Government Documents Department
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Flight tests of an apparatus for varying dihedral effect in flight

Description: Report presenting a new apparatus for varying the effective dihedral in flight by means of servo actuation of the ailerons in response to sideslip angle. Results regarding the characteristics of the effective-dihedral control in steady sideslips, in abrupt rudder kicks, and in lateral oscillations are provided.
Date: December 1948
Creator: Kauffman, William M.; Smith, Allan; Liddell, Charles J., Jr. & Cooper, George E.
Partner: UNT Libraries Government Documents Department
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A Generalized Theoretical and Experimental Investigation of the Motions and Hydrodynamic Loads Experienced by V-Bottom Seaplanes During Step-Landing Impacts

Description: Note presenting a theoretical investigation made of the motions and hydrodynamic loads experienced by V-bottom seaplanes during the course of a step-landing impact. In the analysis, the primary flow about the immersed portion of a keeled float or hull is considered to occur in transverse flow planes and the virtual-mass concept is applied to calculate the reaction of the water to the motion of the seaplane. The results are presented in the form of dimensionless curves which may be used to predi… more
Date: February 1948
Creator: Milwitzky, Benjamin
Partner: UNT Libraries Government Documents Department
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A rapid compression machine suitable for studying short ignition delays

Description: Report presenting an examination of a machine developed to study the ignition delay of fuels by means of a rapid adiabatic compression. The essential features of the machine are that the compression is completed in about 0.006 second, provision is made for obtaining simultaneous records of piston motion and cylinder pressure, and the combustion cylinder is unlubricated. An extensive explanation of the components of the machine and its applicability to different scenarios are provided.
Date: February 1948
Creator: Leary, W. A.; Taylor, E. S.; Taylor, C. F. & Jovellanos, J. U.
Partner: UNT Libraries Government Documents Department
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Stability derivatives of thin rectangular wings at supersonic speeds: Wing diagonals ahead of tip mach lines

Description: Report presenting theoretical results for the surface-velocity-potential functions, surface-pressure distributions, and stability derivatives for various motions at supersonic speeds of thin flat rectangular wings without dihedral. The investigation included steady and accelerating vertical and longitudinal motions and steady rolling, yawing, sideslipping, and pitching for Mach numbers are provided.
Date: November 1948
Creator: Harmon, Sidney M.
Partner: UNT Libraries Government Documents Department
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Calculation of the Effect of Thrust-Axis Inclination on Propeller Disk Loading and Comparison With Flight Measurements

Description: Note presenting an analysis based on simple geometry of the effect of thrust-axis inclination on propeller disk loading. Calculations are in excellent agreement with available flight measurements, so that the analysis is indicated to be adequate for predicting the primary effects of inclination. Because of the possible large effects of wing and fuselage interference, flow angles at the propeller should be determined by survey for most accurate results.
Date: October 1948
Creator: Vogeley, A. W.
Partner: UNT Libraries Government Documents Department
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Two-dimensional compressible flow in conical mixed-flow compressors

Description: Report presenting a general method of analysis developed for the two-dimensional, steady, compressible flow through mixed-flow compressors in which the center line of the passage generates a right circular cone about the axis of the compressor. The two-dimensional, radial-discharge compressor is a special case in which the cone angle is equal to 180 degrees. The general analysis also applies to inward-flow turbines.
Date: November 1948
Creator: Stanitz, John D.
Partner: UNT Libraries Government Documents Department
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An Improved Photoelastic Method for Determining Plane Stresses

Description: Note presenting an improved photoelastic method that has been developed for determining stress concentrations which occur in nonisotropic materials under load. Drucker's method has been extended by means of an additional oblique photograph, and simpler equations for relating fringe order to principal stresses were obtained. The conclusion indicates that the improved oblique method of photoelastic analysis yields reasonably accurate results over regions of the photoelastic model which are not su… more
Date: January 1948
Creator: Norris, C. B. & Voss, A. W.
Partner: UNT Libraries Government Documents Department
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Effect of Simulated Service Conditions on Plastics During Accelerated and 2-Year Weathering Tests

Description: "The effects of outdoor weathering for 2 years and of an accelerated weathering test on the weight, dimensional stability, and flexural properties of selected reinforced plastics were investigated. The results of all tests, both in this report and the previous report (NACA TN No. 1240), indicate that none of the laboratory aging tests correlated with outdoor weathering with respect to all properties and all materials" (p. 1).
Date: May 1948
Creator: Crouse, W. A.; Caudill, D. C. & Reinhart, F. W.
Partner: UNT Libraries Government Documents Department
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