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Development and Construction of an Interferometer for Optical Measurements of Density Fields

Description: "A method of interference is described in the present report which promises profitable application in aeronautical research. The physical foundation of the method and a simple method of adjustment are briefly discussed. The special technical construction of the instrument is described which guarantees its use also in the case of vibrations of the surrounding space and permits the investigation of unsteady phenomena" (p. 1).
Date: September 1947
Creator: Zobel
Partner: UNT Libraries Government Documents Department

NACA Conference on Aircraft Loads, Structures, and Flutter

Description: "This document contains reproductions of technical papers on some of the most recent research results on aircraft loads, flutter, and structures from the NACA laboratories. These papers were presented by members of the staff of the NACA laboratories at the Conference held at the Langley Aeronautical Laboratory March 5, 6, and 7, 1957. The primary purpose of this Conference was to convey to contractors of the military services and others concerned with the design of aircraft these recent research results and to provide those attending an opportunity to discuss the results" (p. 6).
Date: March 5, 1957
Partner: UNT Libraries Government Documents Department

NACA: University Conference on Aerodynamics: A Compilation of the Papers Presented

Description: This document contains reproductions of the technical papers presented at the NACA - University Conference on Aerodynamics held at the Langley Aeronautical Laboratory on June 21, 22, and 23, 1948. The conference was held in recognition of the difficulties, imposed by security restrictions, in keeping abreast of the rapid advances in aerodynamics. The papers were prepared to review the status of a number of fields of interest, to summarize the more important wartime advances that are no longer classified, and to orient reference material for further study.
Date: 1948-06-21/1948-06-23
Partner: UNT Libraries Government Documents Department

Pressure Distribution Measurements on a Turbine Rotor Blade Passing Behind a Turbine Nozzle Lattice

Description: "As a turbine rotor turns, the blades traverse the wake zones of the nozzle vanes. A periodic fluctuation of the pressure distribution around the circumference of the rotor blade is therefore caused. It was desired to investigate quantitatively this effect. At the same time, the magnitude of the force acting upon one profile of the rotor-blade lattice at various positions of this lattice relative to the nozzle lattice was to be determined" (p. 1).
Date: September 1947
Creator: Hausenblas
Partner: UNT Libraries Government Documents Department

NACA Conference on Aerodynamics of High Speed Aircraft

Description: "This document contains reproductions of technical papers presented by staff members of the NACA Laboratories at the NACA Conference on Aerodynamics of High-Speed Aircraft held at the Langley Aeronautical Laboratory November 1, 2, and 3, 1955. The primary purpose of the conference was to convey to contractors of the military services and others concerned with the design of aircraft the results of recent research and to provide those attending with an opportunity to discuss these results. The papers in this document are in the same form in which they were orally presented at the conference to facilitate their prompt distribution" (p. vii).
Date: 1955-11-01/1955-11-03
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

Preliminary Indications of the Cooling Achieved by Ejecting Water Upstream From the Stagnation Point of Hemispherical, 80 Degree Conical, and Flat-Faced Nose Shapes at a Stagnation Temperature of 4,000 F

Description: Memorandum presenting an investigation of the effectiveness of water-vaporization cooling that would be obtained by ejecting water upstream from the stagnation point conducted in a liquid-fuel rocket jet as a stagnation temperature of 4000 degrees Fahrenheit.
Date: October 23, 1957
Creator: Rashis, Bernard
Partner: UNT Libraries Government Documents Department

Airfoil Section Data From Tests of 10 Practical-Construction Sections of Helicopter Rotor Blades Submitted by the Sikorsky Aircraft Division, United Aircraft Corporation

Description: Report presenting 10 practical-construction models of sections of helicopter rotor blades tested in the NACA two-dimensional low-turbulence pressure tunnel at atmospheric pressure. Lift, drag, and pitching-moment characteristics of blades representing the present method of construction of the YR-4A helicopter were determined.
Date: September 1944
Creator: Tetervin, Neal
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

High-Altitude Cooling 6: Axial-Flow Fans and Cooling Power

Description: Report presenting the theory, design, and effect on cooling of the constant-velocity axial-flow fan as related to the problem of high-altitude aircraft engine cooling. The existing theory of the axial-flow fan, including a discussion of the fan losses, is summarized.
Date: September 1944
Creator: Mutterperl, William
Partner: UNT Libraries Government Documents Department

A Method for the Rapid Estimation of Turbulent Boundary-Layer Thickness for Calculating Profile Drag

Description: "An analysis is developed that makes it possible to integrate von Kármán's boundary-layer momentum equation directly. For this purpose, the skin friction coefficient is expressed as a function of the Reynolds number based on the boundary-layer momentum thickness and the boundary-layer shape is assumed to be constant. The integrated equation permits the boundary-layer momentum thickness at the airfoil trailing edge to be rapidly determined for the estimation of airfoil profile-drag coefficients" (p .1).
Date: July 1944
Creator: Tetervin, Neal
Partner: UNT Libraries Government Documents Department

A Method of Calculating Bending Stresses Due to Torsion

Description: Report presenting a method for analyzing bending stresses due to torsion in a box with variable cross section and loading by means of a recurrence formula leading to a set of equations identical in form with the well-known three-moment equations. An approximate form of the general method of analysis is presented that eliminates the need of solving a system of equations.
Date: December 1942
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department

Method of Calculating Performance of Dual-Rotating Propellers From Airfoil Characteristics

Description: "A method is developed for calculating the performance of a dual-rotating propeller from the section characteristics of the blade elements. The method is applied to an eight-blade dual-rotating propeller and the computed results are compared with low-speed wind-tunnel tests of the same propeller in both the tractor and pusher positions. The computations are found to agree within the experimental accuracy of the measurements" (p. 1).
Date: May 1943
Creator: Naiman, Irven
Partner: UNT Libraries Government Documents Department

The NACA Oil-Damped V-G Recorder

Description: Note presenting the development of a NACA oil-damped V-G recorder in which viscous damping of accelerometer results in improved frequency response, reduces susceptibility to vibration, and eliminates the necessity for field adjustments of damping.
Date: October 1950
Creator: Taback, Israel
Partner: UNT Libraries Government Documents Department

A Method for Finding a Least-Squares Polynomial That Passes Through a Specified Point With Specified Derivatives

Description: "A method is presented for finding an mth-degree polynomial that passes through a specified point with (m - j) specified derivatives (l ≤ j ≤ m) and is a least-squares polynomial for other points spaced at unequal intervals of the independent variable" (p. 1).
Date: September 1952
Creator: Tetervin, Neal
Partner: UNT Libraries Government Documents Department

Method for Evaluating From Shadow or Schlieren Photographs the Pressure Drag in Two-Dimensional or Axially Symmetrical Flow Phenomena With Detached Shock

Description: "A method has been developed for evaluating from shadow or schileren photographs the pressure drag of axially symmetrical bodies at zero angle of attack or of two-dimensional bodies producing detached shock. The method consists in the determination of the flow properties along a characteristic line and the application of the momentum theorem to a stream tube around the body. The method can be applied to the determination of external drag of supersonic inlets with subsonic flow at the entrance of the inlet" (p. 1).
Date: February 1949
Creator: Ferri, Antonio
Partner: UNT Libraries Government Documents Department

Preliminary Vibration and Flutter Studies on P-47 Tail

Description: Report presenting a report illustrated by photographs and vibration records on the failure of the P-47 rudder in the high-speed tunnel at a true speed of 468 miles per hour and a density corresponding to 9000 feet altitude. The fin-rudder unit was tested as being at least representative of the tail design of the P-47 airplane.
Date: August 1943
Creator: Theodorsen, Theodore
Partner: UNT Libraries Government Documents Department

An Analysis of Normal Accelerations and Airspeeds of One Type of Twin-Engine Transport Airplane in Commercial Operations Over a Northern Transcontinental Route

Description: Note presenting normal-acceleration and airspeed data obtained for one type of twin-engine transport airplane in commercial operations in order to determine the gust and gust-load experiences of the airplane. Results regarding acceleration experience, gust experience, seasonal effects, and effect of special operating restriction are provided.
Date: November 1952
Creator: Steiner, Roy
Partner: UNT Libraries Government Documents Department

Airfoil-Contour Modifications Based on (Epsilon)-Curve Method of Calculating Pressure Distribution

Description: From Introduction: "Certain alternations of a qualitative nature may be performed in spite of the fact that a pressure change cannot be prescribed. It is the purpose of this paper to indicate a method by which qualitative alternation may be performed. It will be noted that the present method of contour modification will serve the intended purpose of the inverse method."
Date: July 1944
Creator: Theodorsen, Theodore
Partner: UNT Libraries Government Documents Department