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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

On Traveling Waves in Beams

Description: Note presenting the basic equations of Timoshenko for the motion of vibrating non-uniform beams, which allow for effects of transverse shear deformation and rotary inertia, in several forms, including one in which the equations are written in the directions of the characteristics. Numerical traveling-wave solutions are obtained for some elementary problems of finite uniform beams for which the propagation velocities of bending and shear discontinuities are taken to be equal.
Date: January 1953
Creator: Leonard, Robert W. & Budiansky, Bernard
Partner: UNT Libraries Government Documents Department

Aircraft Engine Design

Description: From Introduction: "The subject of this paper is so broad in scope that a large volume might be devoted to it. In a short paper of this kind it is possible simply to sketch in the high lights of aircraft engine design showing the development to date, the possibilities of the future, and the underlying fundamental principles. Summarizing this development and referring to the graph (Fig.1), we that there is now a water-cooled engine in every power from 150 to 800 HP. and an air-cooled engine in the 200 to 400 HP. classes."
Date: January 1925
Creator: Wilson, E. E.
Partner: UNT Libraries Government Documents Department

Investigation of Gases Evolved During Firing of Vitreous Coatings on Steel

Description: Note presenting an investigation of the gases evolved during the firing of vitreous coatings. The scope of the investigation included an examination of gas evolution with a microscope while specimens were being fired, examinations of fired specimens for changes in bubble structure with firing time, examination of changes in normal gas evolution when water-free enamels were used, analysis with the mass spectrometer of gases trapped in the bubble structure, determination of the source of carbon gases in the bubble structure with radioactive carbon as a tracer, and determination of the effect of various pretreatments of the clay used for suspending the coating slip on the resulting bubble structure of the fired specimens.
Date: January 1953
Creator: Moore, Dwight G. & Mason, Mary A.
Partner: UNT Libraries Government Documents Department

An Optical Altitude Indicator for Night Landing

Description: One of the most ingenious of the devices intended for use in night landing, especially emergency landing, is a very simple optical instrument known as the Jenkins night altitude indicator. The design and operation of this instrument, which allows a pilot to determine the altitude of the aircraft, is discussed. The author discusses various modifications and improvements that might be made to the instrument.
Date: January 1923
Creator: Warner, John A. C.
Partner: UNT Libraries Government Documents Department

Investigation of Laminar Boundary Layer in Compressible Fluids Using the Crocco Method

Description: Note presenting the use of the Crocco method to solve the simultaneous differential equations of momentum and energy involved in the flow of air in a thin laminar boundary layer on a flat plate. The Crocco method was used because it gave accurate results for arbitrary Prandtl number near unity. Variations of shear, velocity, temperature, and Mach number across the boundary layer are included.
Date: January 1952
Creator: Van Driest, E. R.
Partner: UNT Libraries Government Documents Department

Investigation of Rotating Stall in a Single-Stage Axial Compressor

Description: Note presenting an investigation of the rotating-stall characteristics of a single-stage axial-flow compressor. The number of stall cells and their propagation velocities were found with and without stator blades. Results regarding steady-state characteristics, stall characteristics with stator blades, stall characteristics without stator blades, a comparison of actual and predicted propagation velocities, and pressure fluctuations are provided.
Date: January 1957
Creator: Montgomery, S. R. & Braun, J. J.
Partner: UNT Libraries Government Documents Department

Investigation of Variation in Base Pressure Over the Reynolds Number Range in Which Wake Transition Occurs for Nonlifting Bodies of Revolution at Mach Numbers From 1.62 to 2.62

Description: Note presenting an investigation to determine the Reynolds and Mach number effects on the base pressure of a nonlifting ogival body of revolution over the Reynolds number range in which wake transition occurs. The results were compared with previous base-pressure data and also with the qualitative theoretical predictions of Crocco and Lees.
Date: January 1957
Creator: Van Hise, Vernon
Partner: UNT Libraries Government Documents Department

Instrumentation for Measurements of Free-Space Sound Pressures in the Immediate Vicinity of a Propeller in Flight

Description: Note presenting a description of instrumentation suitable for making in-flight measurements of the free-space sound pressures in the immediate vicinity of a propeller in forward flight. A description of the system, which consists of a microphone, probe, telemeter, and analyzer is provided.
Date: January 1956
Creator: Mace, William D.; Haney, Francis J. & Brummer, Edmund A.
Partner: UNT Libraries Government Documents Department

The Spacing of Orifices for the Measure of Pressure Distributions

Description: "The following report has been prepared for publication by the NACA. Suitable locations of orifices for the measurement of pressure distributions have been discussed. Tables are given for quickly laying out these locations and for quickly and easily computing the resultant air forces from the result of the measurements" (p. 1).
Date: January 1926
Creator: Munk, Max M.
Partner: UNT Libraries Government Documents Department

Sideslip Angles and Vertical-Tail Loads Developed by Periodic Control Deflections

Description: Note presenting a consideration of dynamic maneuvers consisting of periodic rudder and aileron control deflections with respect to the maximum sideslip angles developed and the position of the rudder at the time of maximum sideslip. A method is also given for computing the maximum sideslip angles when the forces and moments are nonlinear functions of the sideslip.
Date: January 1948
Creator: Lomax, Harvard
Partner: UNT Libraries Government Documents Department

Tests of Aluminum-Alloy Stiffened-Sheet Specimens Cut From an Airplane Wing

Description: "The specimens used in the present tests were cut from an actual airplane wing of the stressed-skin type. The specimens thus obtained were not representative of the usual type of laboratory specimens because the stiffeners were not exactly parallel nor evenly spaced and, in one case, the skin consisted of pieces of sheet of different thicknesses. The test data obtained indicate that the buckling strain of stiffened curved sheet can be computed with reasonable accuracy by the equation given by Wenzek" (p. 1).
Date: January 1943
Creator: Holt, Marshall
Partner: UNT Libraries Government Documents Department

Tests on a Model of the D.F.W. Airplane T-29 of The "Deutsche Flugzeug Derke" (German Airplane Works)

Description: 'Experiments similar to those carried out with the A.E.G (Allgemeine Elektrizitats-Gesellschaft) were made in the small wind tunnel of the Gottingen laboratory on a model of the D.F.W. airplane T-29. Three series of tests were carried out on the model with a velocity head (or dynamic pressure) of 5 kg/sq m (1.02 lb/sq ft), during which one of the movable surfaces was deflected at various angles, while both the others were retained in their central positions. Of special interest among the results of the tests is the different run of the elevating moments" (p. 1).
Date: January 1924
Creator: Molthan, Wilhelm
Partner: UNT Libraries Government Documents Department

Simplified Propeller Design for Low-Powered Airplanes

Description: "The object of this report is to furnish the designer and builder of small airplanes a simple system for designing the propeller and making the drawing. An empirical design method is used, based on tests of model propellers in a wind tunnel and full scale tests of propellers in flight. The actual designing is accomplished by means of charts and involves very little calculation" (p. 1).
Date: January 1925
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

The Tracer Gas Method of Determining the Charging Efficiency of Two-Stroke-Cycle Diesel Engines

Description: "A convenient method has been developed for determining the scavenging efficiency or the charging efficiency of two-stroke-cycle engines. The method consists of introducing a suitable tracer gas into the inlet air of the running engine and measuring chemically its concentration both in the inlet and exhaust gas. Monomethylamine CH(sub 3)NH(sub 2) was found suitable for the purpose as it burns almost completely during combustion, whereas the "short-circuited" portion does not burn at all and can be determined quantitatively in the exhaust" (p. 1).
Date: January 1942
Creator: Schweitzer, P. H. & DeLuca, Frank, Jr.
Partner: UNT Libraries Government Documents Department

Torsional Elastic Properties of 18:8 Chromium-Nickel Steel as Affected by Plastic Deformation and by Heat Treatment

Description: Note presenting a study made of the relationship between torsional stress, strain, and permanent set for 18:8 chromium-nickel steel in the annealed, half-hard, and hard conditions. The influence of plastic extension, plastic torsion, and annealing temperature on the torsional elastic properties is discussed.
Date: January 1943
Creator: Mebs, R. W. & McAdam, D. J., Jr.
Partner: UNT Libraries Government Documents Department

Large-Deflection Theory for End Compression of Long Rectangular Plates Rigidly Clamped Along Two Edges

Description: "The von Karman equations for flat plates are solved beyond the buckling load up to edge strains equal to eight time the buckling strain, for the extreme case of rigid clamping along the edges parallel to the load. Deflections, bending stresses, and membrane stresses are given as a function of end compressive load. The theoretical values of effective width are compared with the values derived for simple support along the edges parallel to the load" (p. 1).
Date: January 1943
Creator: Levy, Samuel & Krupen, Philip
Partner: UNT Libraries Government Documents Department

Propeller Rotation Noise Due to Torque and Thrust

Description: "Sound pressure of the first four harmonics of rotation from a full-scale two-blade propeller were measured and are compared with values calculated from theory. The comparison is made (1) for the space distribution with constant tip speed and (2) for fixed space angles with variable tip speed. A relation for rotation noise from an element of radius developed by Gutin is given showing the effect of number of blades on the rotation noise" (p. 1).
Date: January 1940
Creator: Deming, Arthur F.
Partner: UNT Libraries Government Documents Department

Note on the Relative Effect of the Dihedral and the Sweep Back of Airplane Wings

Description: "Dihedral and sweep back can properly be compared only to the extent to which their action is similar in a side slip. In general the rolling moments due to side slip are about three to six times greater for a given dihedral angle than for an equal angle of sweep back" (p. 1).
Date: January 1924
Creator: Munk, Max M.
Partner: UNT Libraries Government Documents Department

On the Permeability of Porous Materials

Description: Note presenting an investigation of the effects on porous-material permeability characteristics of the absolute pressure level, choking of the flow, bending the material, and other factors. Experiments showed permeability characteristics to be appreciably affected by absolute pressure level, flow choking, and thickness of the material. Results regarding testing with wire cloth and sintered metal are provided.
Date: January 1956
Creator: Yates, E. Carson, Jr.
Partner: UNT Libraries Government Documents Department