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Charts for the Computation of Equilibrium Composition of Chemical Reactions in the Carbon-Hydrogen-Nitrogen System at Temperatures from 2000 to 5000 Degrees K

Description: Charts are provided for the estimation and progressive adjustment of two independent variables on which the calculations are based. Additional charts are provided for the graphical calculation of the composition.
Date: July 1948
Creator: Huff, Vearl N. & Calvert, Clyde S.
Partner: UNT Libraries Government Documents Department

The Method of Characteristics for the Determination of Supersonic Flow Over Bodies of Revolution at Small Angles of Attack

Description: Note presenting the use of the method of characteristics for the determination of the supersonic-flow properties around bodies of revolution at a small angle of attack. The system developed considers the effect of the variation of entropy due to the curved shock and determines a flow that exactly satisfies the boundary conditions in the limits of the simplifications assumed.
Date: February 1949
Creator: Ferri, Antonio
Partner: UNT Libraries Government Documents Department

A New Method of Analyzing Extreme-Value Data

Description: Note presenting a method for analyzing extreme-value data which may arise in a wide variety of applications. Discussion of the method is preceded by the necessary statistical theory which also furnishes a basis for evaluating the new method in relation to existing ones. Several appendices are also included for mathematical developments not included in the text.
Date: January 1954
Creator: Lieblein, Julius
Partner: UNT Libraries Government Documents Department

On the Use of a Damped Sine-Wave Elevator Motion for Computing the Design Maneuvering Horizontal-Tail Load

Description: Note presenting a damped sine-wave elevator motion used as a basis for computing the design maneuvering load on the horizontal tail. The results indicated that the maneuvering tail-load variation computed by operational methods with the assumed damped sine-wave elevator motion agreed closely with the loads computed by a method currently used by the US Air Force.
Date: January 1953
Creator: Sadoff, Melvin
Partner: UNT Libraries Government Documents Department

Preliminary Wind-Tunnel Investigation at Low Speed of Stability and Control Characteristics of Swept Back Wings

Description: Note presenting tests conducted on untapered constant-span wings of 0, 30, 45, and 60 degrees sweepback. The purpose of the tests was to investigate the effect of sweepback on stability and control characteristics. The data showed large changes in longitudinal stability at moderate lift coefficients for the 45 and 60 degree sweptback wings.
Date: April 1946
Creator: Letko, William & Goodman, Alex
Partner: UNT Libraries Government Documents Department

Principle and Application of Complementary Energy Method for Thin Homogeneous and Sandwich Plates and Shells With Finite Deflections

Description: Note presenting the principle of complementary energy in the nonlinear elasticity theory, which is shown to be derivable from the principle of potential energy by a Legendre type of transformation. The expression of the complementary energy is derived for homogeneous and sandwich plates and shells with large deflections. The stress-strain relations are derived for homogeneous shells, sandwich plates, and sandwich shells.
Date: February 1952
Creator: Wang, Chi-Teh
Partner: UNT Libraries Government Documents Department

The Aerodynamic Effect of a Retractable Landing Gear

Description: "Tests were conducted in the N.A.C.A. full scale wind tunnel at the request of the Army Air Corps to determine the effect of retractable landing gear openings in the bottom surface of a wing upon the characteristics of a Lockheed Altair airplane. The tests were extended to include the determination of the lift and drag characteristics throughout the angle-of-attack range with the landing gear both retracted and extended. Covering the wheel openings in the wing with sheet metal when the wheels were extended reduced the drag only 2 percent at a lift coefficient of 1.0, which was assumed for the take-off condition" (p. 1).
Date: March 1933
Creator: DeFrance, Smith J.
Partner: UNT Libraries Government Documents Department

Airplane Balance

Description: The authors argue that the center of gravity has a preponderating influence on the longitudinal stability of an airplane in flight, but that manufacturers, although aware of this influence, are still content to apply empirical rules to the balancing of their airplanes instead of conducting wind tunnel tests. The author examines the following points: 1) longitudinal stability, in flight, of a glider with coinciding centers; 2) the influence exercised on the stability of flight by the position of the axis of thrust with respect to the center of gravity and the whole of the glider; 3) the stability on the ground before taking off, and the influence of the position of the landing gear. 4) the influence of the elements of the glider on the balance, the possibility of sometimes correcting defective balance, and the valuable information given on this point by wind tunnel tests; 5) and a brief examination of the equilibrium of power in horizontal flight, where the conditions of stability peculiar to this kind of flight are added to previously existing conditions of the stability of the glider, and interfere in fixing the safety limits of certain evolutions.
Date: June 1921
Creator: Huguet, L.
Partner: UNT Libraries Government Documents Department

Analysis of a Strut With a Single Elastic Support in the Span, With Applications to the Design of Airplane Jury-Strut Systems

Description: Report presenting an analysis of a wing brace with a small auxiliary strut, which is attached to the wing spar at the upper end. The design is quite effective but has some difficult analysis problems. The report is broken into two parts; one is a theoretical investigation and one is an experimental investigation.
Date: May 1935
Creator: Schwartz, A. Murray & Bogert, Reid
Partner: UNT Libraries Government Documents Department

Bending of Rectangular Plates With Large Deflections

Description: Note presenting Von Kármán's equations for thin plates with large deflections are solved for the special cases of rectangular plates with ratios of length to width of 1.5 and 2 and loaded by uniform normal pressure. The boundary conditions are such to approximate panels with riveted edges under normal pressure greater than that of the surrounding panels.
Date: April 1948
Creator: Wang, Chi-Teh
Partner: UNT Libraries Government Documents Department

Bending Stresses Due to Torsion in Cantilever Box Beams

Description: "The paper beings with a brief discussion on the origin of the bending stresses in cantilever box beams under torsion. A critical survey of existing theory is followed by a summary of design formulas; this summary is based on the most complete solution published but omits all refinements considered unnecessary at the present state of development. Strain-gage tests made by NACA to obtained some experimental verification of the formulas are described next. Finally, the formulas are applied to a series of box beams previously static-tested by the U.S. Army Air Corps; the results show that the bending stresses due to torsion are responsible to a large extent for the free-edge type of failure frequently experienced in these tests" (p. 1).
Date: June 1935
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department

The Behavior of Thin-Will Monocoque Cylinders Under Torsional Vibration

Description: "Curves of forced frequency against amplitude are presented for the conditions where the forced frequency is both increased and decreased into the resonant range. On the basis of these curves it is shown that the practical resonance frequency is the point where wrinkling first occurs and that the resonance frequency will be subject to considerable travel once permanent wrinkles appear in the vibrating shell. The decreasing mode of striking resonance is found to be by far the most destructive condition" (p. 1).
Date: August 1937
Creator: Pekelsma, Robert E.
Partner: UNT Libraries Government Documents Department

A Method of Designing Turbomachine Blades With a Desirable Thickness Distribution for Compressible Flow Along an Arbitrary Stream Filament of Revolution

Description: Note presenting a rapid method for designing turbomachine blades of a given turning and a desirable blade-thickness distribution for a compressible non-viscous fluid flow along an arbitrary stream filament of revolution. The method is illustrated with the design of several turbine cascades of highly cambered thick blades.
Date: September 1951
Creator: Wu, Chung-Hua & Brown, Curtis A.
Partner: UNT Libraries Government Documents Department

Nondestructive Measurement of Residual and Enforced Stresses by Means of X-Ray Diffraction 2: Some Applications to Aircraft Problems

Description: Note presenting tests on the use of x-ray diffraction methods for determining surface stress distributions in notched tensile bars and in the vicinity of a welded joint in aircraft steel tubing. Data on the effects of stress and degree of notching on the principal stresses and stress-concentration factors for flat notched tensile-test specimens were obtained.
Date: November 1945
Creator: Sachs, George; Smith, Charles S.; Lubahn, Jack D.; Davis, Gordon E. & Ebert, Lynn J.
Partner: UNT Libraries Government Documents Department

An Exploration of the Longitudinal Tensile and Compressive Properties Throughout an Extruded Shape of 24S-T Aluminum Alloy

Description: Note presenting an investigation of tensile and compressive properties of specimens cut from an extruded shape of 24S-T aluminum alloy. The tensile strengths, tensile yield strengths, elongations, and compressive yield strengths of both the uncrystallized and recrystallized portions were determined. The strength of a cross section of an extruded shape is the weighted average of the strengths of the unrecrystallized and the recrystallized areas.
Date: December 1942
Creator: Paul, D. A.
Partner: UNT Libraries Government Documents Department

Measurements of Lift Fluctuations Due to Turbulence

Description: Note presenting a study of the fluctuating lift of a rigid wing in turbulent flow and the power spectra of the lift and turbulent fluctuations. Using these measurements, the aerodynamic admittance of the wing was obtained. Results regarding the infinite wing and aspect-ratio effect are provided.
Date: March 1957
Creator: Lamson, P.
Partner: UNT Libraries Government Documents Department

Measurements of Recovery Factors and Coefficients of Heat Transfer in a Tube for Subsonic Flow of Air

Description: Note presenting measurements of heat flow to air at subsonic velocities and substantially constant Reynolds number, which show that the heat-transfer coefficient is independent of the difference between the temperature of the heated wall and the adiabatic wall temperature. Recovery factors are measured at the pipe wall for adiabatic flow.
Date: June 1945
Creator: McAdams, William H.; Nicolai, Lloyd A. & Keenan, Joseph H.
Partner: UNT Libraries Government Documents Department

Flight Measurements of the Flying Qualities of Five Light Airplanes

Description: Note presenting results of an investigation made to determine measurements of stability, controllability, and stalling characteristics of five light airplanes. Results regarding the longitudinal stability and control characteristics, lateral stability and control characteristics, stalling characteristics, spinning characteristics, and effect of slots on flying qualities are provided.
Date: May 1948
Creator: Hunter, Paul A.
Partner: UNT Libraries Government Documents Department

The Flow About a Section of a Finite-Aspect-Ratio NACA 0018 Airfoil on a Transonic Bump

Description: Note presenting pressure distributions on a semispan rectangular wing model with an NACA 0015 airfoil section and a moderate aspect ratio at one spanwise station in tests made on a transonic bump in the 16-foot high-speed wind tunnel. The results indicated that at a fixed angle of attack, a region developed over the airfoil wherein the Mach number at each point remained essentially constant as the free-stream Mach number was increased above the critical.
Date: October 1953
Creator: Mellenthin, Jack A.
Partner: UNT Libraries Government Documents Department