UNT Libraries Government Documents Department - 370 Matching Results

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Adsorbent clays: their distribution, properties, production, and uses

Description: From Abstract: "This bulletin is a summary of present knowledge of the adsorbent or bleaching clays-their distribution, field and laboratory identification, physical and chemical properties, uses, quality, and value. Problems in the drying, treating with acids, and washing are discussed, and methods of testing and rating decolorizing efficiency are described."
Date: 1943
Creator: Nutting, P. G.

Aerodynamic and hydrodynamic tests of a family of models of flying hulls derived from a streamline body -- NACA model 84 series

Description: Report discussing a series of related forms of flying-boat hulls representing various degrees of compromise between aerodynamic and hydrodynamic requirements was tested in Langley Tank No. 1 and in the Langley 8-foot high-speed tunnel. The purpose of the investigation was to provide information regarding the penalties in water performance resulting from further aerodynamic refinement and, as a corollary, to provide information regarding the penalties in range or payload resulting from the retention of certain desirable hydrodynamic characteristics. The information should form a basis for over-all improvements in hull form.
Date: 1943
Creator: Parkinson, John B.; Olson, Roland E.; Draley, Eugene C. & Luoma, Arvo A.

Altitude rating of electrical apparatus

Description: From Introduction: "This paper studies the effect of altitude on the ratings of rotating electric machines and after determining the fundamental principles involved, discusses these in relation to the application of such machines in modern aircraft."
Date: January 1943
Creator: Lebenbaum, Paul, Jr

The analysis of strains indicated by multiple-strand resistance-type wire strain gages used as rosettes

Description: From Summary: "Methods are given for making the necessary corrections to the strains indicated by multiple-strand resistance-type wire strain gages used singly or as rosettes to measure strains at an angle to the principal strain. The results of tests to determine the validity of the methods of correction are reported."
Date: January 1, 1943
Creator: Dow, Norris F

The Coso Quicksilver District, Inyo County, California

Description: From abstract: The Coso quicksilver district, which is in the Coso Range, Inyo County, Calif., produced 231 flasks of quicksilver between 1935 and 1939. The quicksilver mineral, cinnabar, was not recognized in the district until 1929, although the hot springs near the deposits have been known since about 1875...The granitic rock on which much of the sinter rests is considerably altered. The cinnabar was deposited as films and grains in open spaces in the sinter, during one stage in a sequence of hot spring activities that still continues. The amount of sinter in the district is estimated to be about 1,800,000 tons. Although the greater part of this does not contain much cinnabar, the total quantity of such material is large enough to be of interest as a low-grade ore.
Date: 1943
Creator: Ross, Clyde P. & Yates, Robert G.

Derivation of charts for determining the horizontal tail load variation with any elevator motion

Description: Report presenting equations relating the wing and tail loads are derived for a unit elevator displacement. The equations are converted into a nondimensoinal form and charts are given that can be used to predict wing- and tail-load-increment variation for any type of elevator motion and for degrees of airplane stability.
Date: January 1943
Creator: Pearson, Henry A.

Drag Measurements of a Protruding.50-Caliber Machine Gun with Barrel Jacket Removed

Description: Tests were made in 8-ft high-speed wind tunnel to determine the drag reduction possible by eliminating the barrel jacket of a protruding 50-caliber aircraft gun. It was found that the drag of a standard aircraft gun protruding into the air stream at right angles to the flow can be reduced by 23% by discarding the barrel jacket. At 300 mph and sea-level conditions, this amounts to a decrease in drag of from 83 to 64 pounds. A rough surface finish on the barrel was found to have no adverse effects on the drag of the barrel, the drag being actually less at high Mach Numbers.
Date: January 1943
Creator: Luoma, Arvo A.

The Effect of Compressibility on the Growth of the Laminar Boundary Layer on Low-Drag Wings and Bodies

Description: The development of the laminar boundary layer in a compressible fluid is considered. Formulas are given for determining the boundary-layer thickness and the ratio of the boundary-layer Reynolds number to the body Reynolds number for airfoils and bodies of revolution. It i s shown that the effect of compressibility will profoundly alter the Reynolds number corresponding to the upper limit of the range of the low-drag coefficients . The available data indicate that for low-drag and high critical compressibility speed airfoils and bodies of revolution, this effect is favorable.
Date: January 1943
Creator: Allen, H. Julian & Nitzberg, Gerald E.

The effect of compressibility on two-dimensional tunnel-wall interference for a symmetrical airfoil

Description: Summary: The effective change in the velocity of flow past a wing section, caused by the presence of wind-tunnel walls, is known for potential flow. This theory is extended by investigation of the two-dimensional compressible flow past a thin Rankine Oval. It is shown that for a symmetrical section at zero angle of attack the velocity increment due to the tunnel walls in the incompressible case must be multiplied by the factor 1/1-M^2 to take account of compressibility effects. The Mach number, M, corresponds to conditions in the wind-tunnel test section with the model removed (p. 1.).
Date: January 1, 1943
Creator: Nitzberg, Gerald E

The effect of mass distribution on the lateral stability and control characteristics of an airplane as determined by tests of a model in the free-flight tunnel

Description: The effects of mass distribution on lateral stability and control characteristics of an airplane have been determined by flight tests of a model in the NACA free-flight tunnel. In the investigation, the rolling and yawing moments of inertia were increased from normal values to values up to five times normal. For each moment-of-inertia condition, combinations of dihedral and vertical-tail area representing a variety of airplane configurations were tested. The results of the flight tests of the model were correlated with calculated stability and control characteristics and, in general, good agreement was obtained.
Date: January 1, 1943
Creator: Campbell, John P & Seacord, Charles L , Jr

Effect of Normal Pressure on the Critical Shear Stress of Curved Sheet

Description: In order to determine the critical stresses caused by an outward acting pressure on the upper surface of a wing due to the difference in internal and external pressures, torsional tests were made on two curved-sheet specimens subjected to an outward acting normal pressure. Results show that an outward acting normal pressure appreciable raises the critical shear stress for an unstiffened curved sheet; the absolute increase in critical shear stress is slightly greater for a 30 in. rib spacing than for a 10 in. rib spacing.
Date: January 1, 1943
Creator: Rafel, Norman

Effect of Rivet Holes on the Ultimate Strength Developed by 24S-T and Alclad 75S-T Sheet in Incomplete Diagonal Tension

Description: Strength tests were made of a number of 24S-T and Alclad 75S-T aluminum-alloy shear webs to determine the effect of rivet or bolt holes on the shear strength. Data were obtained for webs which approached a condition of pure shear stress as well as for webs with well-developed diagonal tension. The rivet factor, (pitch minus diameter) divided by pitch, was varied from approximately 0.81 to 0.62. These tests indicated that the shear stresses on the gross section were nearly constant for all values of the rivet factor investigated if the other properties of the web were not changed.
Date: 1943
Creator: Levin, L. Ross & Nelson, David H.

The exact solution of shear-lag problems in flat panels and box beams assumed rigid in the transverse direction

Description: A mathematical procedure is herein developed for obtaining exact solutions of shear-lag problems in flat panels and box beams: the method is based on the assumption that the amount of stretching of the sheets in the direction perpendicular to the direction of essential normal stresses is negligible. Explicit solutions, including the treatment of cut-outs, are given for several cases and numerical results are presented in graphic and tabular form. The general theory is presented in a from which further solutions can be readily obtained. The extension of the theory to cover certain cases of non-uniform cross section is indicated. Although the solutions are obtained in terms of infinite series, the present developments differ from those previously given in that, in practical cases, the series usually converge so rapidly that sufficient accuracy is afforded by a small number of terms. Comparisons are made in several cases between the present results and the corresponding solutions obtained by approximate procedures devised by Reissner and by Kuhn and Chiarito.
Date: January 1, 1943
Creator: Hildebrand, Francis B

Experimental Investigation of Impact in Landing on Water

Description: The extent of agreement of the theoretical impact computations with the actual phenomenon has not as yet been fully clarified. There is on the one hand a certain imperfection in the theory (simplifying assumptions made) and on the other an insufficiency in the experimental data available. The object of our present paper is to show how far test results agree with the available approximate computation methods, to investigate in greater detail the physical nature of impact on water, and to perfect the experimental method of studying the phenomenon.
Date: January 1, 1943
Creator: Kreps, R. L.

An experimental survey of flow across banks of elliptical and pointed tubes

Description: Report presenting an experimental survey of the details of the flow of fluids across banks of streamline tubes as a continuation of previous work. Information that clarifies the picture of flow has been obtained by surveys of total, dynamic, and static pressure, and hot-wire cooling surveys of the unheated tubes.
Date: January 1943
Creator: Joyner, Upshur T. & Palmer, Carl B.

Flight investigation of NACA D(sub S) cowlings on the XP-42 airplane 2: low-inlet-velocity cowling with axial-flow fan and propeller cuffs

Description: Report presenting results from a series of flight tests of the performance and cooling characteristics in high-speed level flight and in climb of the XP-42 airplane equipped with a short-nose low-inlet-velocity cowling and an axial-flow fan mounted on the spinner. Results regarding maximum speed and pressures and temperatures are provided.
Date: January 1943
Creator: Johnston, J. Ford & Voglewede, T. J.

Flight investigation of NACA D(sub S) cowlings on the XP-42 airplane 3: low-inlet-velocity cowling without fan or propeller cuffs, with axial-flow fan alone, and with two different sets of propeller cuffs

Description: Report presenting the results of flight measurements of performance and cooling characteristics of the XP-42 airplane equipped with a short-nose low-inlet-velocity cowling. Testing included measurements in level flight and climb of the effects of a spinner-mounted axial-flow fan without propeller cuffs, no fan or cuffs, and two different sets of propeller cuffs.
Date: January 1943
Creator: Johnston, J. Ford & Voglewede, T. J.

Flight investigation of NACA D(sub S) cowlings on the XP-42 airplane 4: high-inlet-velocity cowling tested in climb with and without propeller cuffs and in high-speed level flight without propeller cuffs

Description: Report presenting flight measurements of the performance and cooling characteristics of a short-nose high-inlet-velocity cowling on the XP-42 for conditions of climb with and without propeller cuffs and for high speed without cuffs. The speed of the airplane was approximately 1 mile per hour greater without propeller cuffs than the previously measured value with cuffs. Results regarding maximum speed, pressures and temperatures, and ground cooling are provided.
Date: January 1943
Creator: Johnston, J. Ford & Voglewede, T. J.