UNT Libraries Government Documents Department - 298 Matching Results

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Creep Strength of Stabilized Wrought-Aluminum Alloys

Description: Rohn-type equipment has been mounted on rubber blocks, for the purpose of damping the vibrations of the ground and of rendering the plastic yielding of the test bars less subject to outside interferences. New equipment also included three shockproof creep-testing machines with the Martens mirror instruments for recording the strain curve of the fatigue-tested specimens.
Date: November 1940
Creator: Müller, W.
Item Type: Refine your search to only Report
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Cyclic stress-strain studies of metals in torsion

Description: Report presenting cyclic torsion tests made to determine the effects of varying amounts of torsional overstrain on the shape of the shearing stress-strain diagrams of aluminum alloy 17ST, mild steel, wrought iron, copper, brass, and magnesium alloy AX57S. Results regarding the tensile, compressive, and shear properties are provided.
Date: December 1940
Creator: Paul, D. A. & Moore, R. L.
Item Type: Refine your search to only Report
open access

Damping formulas and experimental values of damping in flutter models

Description: The problem of determining values of structural damping for use in flutter calculations is discussed. The concept of equivalent viscous damping is reviewed and its relation to the structural damping coefficient g introduced in NACA Technical Report No. 685 is shown. The theory of normal modes is reviewed and a number of methods are described for separating the motions associated with different modes. Equations are developed for use in evaluating the damping parameters from experimental data. Ex… more
Date: February 1940
Creator: Coleman, Robert P.
Item Type: Refine your search to only Report
open access

Design Charts Relating to the Stalling of Tapered Wings

Description: An aid in airplane design, charts have been prepared to show the effects of wing taper, thickness ratio, and Reynolds number on the spanwise location of the initial stalling point. Means of improving poor stalling characteristics resulting from certain combinations of the variables have also been considered; additional figures illustrate the influence of camber increase to the wing tips, washout, central sharp leading edges, and wing-tip slots on the stalling characteristics. Data are included … more
Date: January 18, 1940
Creator: Soulé, H. A. & Anderson, R. F.
Item Type: Refine your search to only Report
open access

The Design of Cooling Ducts With Special Reference to the Boundary Layer at the Inlet

Description: "A study has been made of underslung cooling ducts with special references to the problems presented by the boundary layer on the fuselage skin. It was found that good flow can be obtained in such ducts by (1) making the inlet opening of such size that the mean inlet velocity is about 0.6 the free-stream velocity and (2) providing vanes behind as well as ahead of the radiator. Tables to facilitate design are included, together with an example " (p. 1).
Date: December 1940
Creator: Katzoff, S.
Item Type: Refine your search to only Report
open access

Determination of ground effect from tests of a glider in towed flight

Description: Report presents the results of an investigation made to find the effect of ground on the aerodynamic characteristics of a Franklin PS-2 glider. The lift, the drag, and the angle of attack of the glider in towed flight were determined at several heights from 0.14 to 1.19 span lengths and at various speeds for each height. Two wing arrangements were tested: the plain wing, and the wing with a nearly full-span 30-percent-chord split flap deflected 45 degrees. The experimental results for the plain… more
Date: April 8, 1940
Creator: Wetmore, J. W. & Turner, L. I., Jr.
Item Type: Refine your search to only Report
open access

Determination of the Characteristics of Tapered Wings

Description: This report presents tables and charts for use in determining the characteristics of tapered wings. Theoretical factors are given from which the following characteristics of tapered wings may be found: the span lift distribution, the induced-angle-of attack distribution, the lift-curve slope, the angle of zero lift, the induced drag, the aerodynamic-center position, and the pitching moment about the aerodynamic center.
Date: 1940
Creator: Anderson, Raymond F.
Item Type: Refine your search to only Report
open access

The Development of Electrical Strain Gages

Description: "The design, construction, and properties of an electrical-resistance strain gage consisting of fine wires molded in a laminated plastic are described. The properties of such gages are discussed and also the problems of molding of wires in plastic materials, temperature compensation, and cementing and removal of the gages. Further work to be carried out on the strain gage, together with instrument problems, is discussed" (p. 1).
Date: January 1940
Creator: de Forest, A. V. & Leaderman, H.
Item Type: Refine your search to only Report
open access

DFS Dive-Control Brakes for Gliders and Airplanes and Analytical Study of the Drag of the DFS Dive-Control Brake

Description: These two reports are surveys on the progress and present state of development of dive-control flaps for gliders and airplanes. The second article describes how on the basis of wind tunnel and free-flight tests, the drag increase on brake flaps of the type DFS, can be predicted. Pressure records confirm a two-dimensional load distribution along the brake-flap surface.
Date: January 1940
Creator: Jacobs, Hans & Wanner, Adolf
Item Type: Refine your search to only Report
open access

Diseases and Insects of Garden Vegetables.

Description: Describes a wide variety of insect pests and diseases of vegetables, their characteristics, and the steps farmers can take to prevent, control, and treat these threats.
Date: 1940
Creator: Gilbert, William W. (William Williams), b. 1880; Popenoe, C. H. (Charles Holcomb), 1884-1933 & Caffrey, D. J.
Item Type: Refine your search to only Book
open access

Drag Analysis of Single-Engine Military Airplanes Tested in the NACA Full-Scale Wind Tunnel

Description: Report presenting tests in the full-scale wind tunnel on 11 single-engine military airplanes to investigate methods for increasing their high speed. Results regarding the power-plant installation, flow characteristics, wings, cockpit canopies, landing gear, and air leakage are provided.
Date: October 1940
Creator: Dearborn, C. H. & Silverstein, Abe
Item Type: Refine your search to only Report
open access

Drag and propulsive characteristics of air-cooled engine-nacelle installations for two-engine airplanes

Description: Report presenting a study on wing-nacelle propeller arrangements using a two-engine airplane with nacelles varying in diameter. Results regarding the power-off characteristics, propulsive and overall efficiencies, power-on characteristics, and pressure distributions are provided.
Date: December 1940
Creator: Wilson, Herbert A., Jr. & Lehr, Robert R.
Item Type: Refine your search to only Report
open access

Drag Determinations of the Forward Component of a Tricycle Landing Gear

Description: "Wind-tunnel tests were performed to determine the drag of the front-wheel arrangements of several types of tricycle landing gear. One wheel was tested in arrangements to simulate both nonretracted and partially retracted types. The landing gears were tested in conjunction with a fuselage, and the effects of wheel extension and longitudinal location were determined" (p. 1).
Date: December 1940
Creator: Harmon, Hubert N.
Item Type: Refine your search to only Report
open access

Effect of body nose shape on the propulsive efficiency of a propeller

Description: Report presents the results of an investigation of the propulsive efficiency of three adjustable propellers of 10-foot diameter operated in front of four body nose shapes, varying from streamline nose that continued through the propeller plane in the form of a large spinner to a conventional open-nose radial-engine cowling. One propeller had airfoil sections close to the hub, the second had conventional round blade shanks, and the third differed from the second only in pitch distribution. The b… more
Date: January 29, 1940
Creator: Stickle, George W.; Crigler, John L. & Naiman, Irven
Item Type: Refine your search to only Report
open access

The Effect of Initial Displacement of the Center Support on the Buckling of a Column Continuous Over Three Supports

Description: Report presenting an investigation of a long column continuous over three supports to determine its critical load when the center support was given varying amounts of initial displacement. During each test, the middle support was hinged so as to be free to move parallel to the column axis during buckling. The critical loads predicted from load-deflection readings were different for the upper and lower spans.
Date: November 1940
Creator: Lundquist, Eugene E. & Kotanchik, Joseph N.
Item Type: Refine your search to only Report
open access

The Effect of Initial Displacement of the Center Support on the Buckling of a Column Continuous Over Three Supports

Description: Report presenting a test of a long column continuous over three supports to determine its critical load when the center support was given varying amounts of initial displacement. During each test, the middle support was hinged so as to be free to move parallel to the column axis during buckling.
Date: November 1940
Creator: Lunquist, Eugene E. & Kotanchik, Joseph N.
Item Type: Refine your search to only Report
open access

Effect of Wing Loading, Aspect Ratio, and Span Loading of Flight Performances

Description: "An investigation is made of the possible improvements in maximum, cruising, and climbing speeds attainable through increase in the wing loading. The decrease in wing area was considered for the two cases of constant aspect ratio and constant span loading. For a definite flight condition, an investigation is made to determine what loss in flight performance must be sustained if, for given reasons, certain wing loadings are not to be exceeded. With the aid of these general investigations, the tr… more
Date: January 1940
Creator: Göthert, B.
Item Type: Refine your search to only Report
open access

The Effects of Aerodynamic Heating on Ice Formations on Airplane Propellers

Description: An investigation has been made of the effect of aerodynamic heating on propeller-blade temperatures. The blade temperature rise resulting from aerodynamic heating was measured and the relation between the resulting blade temperatures and the outer limit of the iced-over region was examined. It was found that the outermost station at which ice formed on a propeller blade was determined by the blade temperature rise resulting from the aerodynamic heating at that point.
Date: August 1940
Creator: Rodert, Lewis A.
Item Type: Refine your search to only Report
open access

The effects of engine speed and mixture temperature on the knocking characteristics of several fuels

Description: Six 100-octane and two 87-octane aviation engine fuels were tested in a modified C.F.R. variable-compression engine at 1,500, 2,000 and 2,500 rpm. The mixture temperature was raised from 50 to 300 F in approximately 50 degree steps and, at each temperature, the compression ratio was adjusted to give incipient knock as shown by a cathode ray indicator. The results are presented in tabular form. The results are analyzed on the assumption that the conditions which determine whether a given fuel wi… more
Date: July 1940
Creator: Lee, Dana W.
Item Type: Refine your search to only Report
open access

The Effects of Piston-Head Shape, Cylinder-Head Shape, and Exhaust Restriction, on the Performance of a Piston-Ported Two-Stroke Cylinder

Description: Report presenting testing of a model of the two-stroke engine described in NACA Technical Note No. 674 for the purpose of observing the scavenging-air flow obtained with various inlet-port arrangements. Three types of cylinder head were tried with the round-edge piston in the engine. Results regarding the effect of port arrangement, pistons, cylinder-head shapes, effect of swirl, and exhaust restrictions are provided.
Date: March 1940
Creator: Rogowski, A. R.; Bouchard, C. L. & Taylor, C. Fayette
Item Type: Refine your search to only Report
open access

Emmer and Spelt.

Description: Describes the history, characteristics, production methods, and uses of emmer and spelt.
Date: 1940
Creator: Martin, John H. (John Holmes), 1893- & Leighty, C. E. (Clyde Evert), b. 1882
Item Type: Refine your search to only Book
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