UNT Libraries Government Documents Department - 366 Matching Results

Search Results

Adaptor for measuring principal strains with Tuckerman strain gage
Report discussing an adapter which uses three Tuckerman optical strain gages to measure the displacement of the three vortices of an equilateral triangle along lines 120 degrees apart. These displacements are substituted in well-known equations in order to compute the magnitude and direction of the principal strains. Tests of the adaptor indicate that principal strains over a gage length of 1.42 inch may be measured with a systematic error not exceeding 4 percent and a mean observational error of the order of + or minus 0.000006. The maximum observed error in strain was of the order of 0.00006. The directions of principal strains for unidirectional stress were measured with the adaptor with an average error of the order of 1 degree.
Additional design charts relating to the stalling of tapered wings
From Introduction: "The present report, therefore, may be considered a supplement to reference 1. The combined scope of the stall charts of reference 1, designated A, and of the present work, designated B, is summarized in the following table: For the wing with root thickness ratio to 18 was also investigated.
Adsorbent clays: their distribution, properties, production, and uses
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."
The advantages of uniform fuel distribution for air-cooled engines from considerations of cooling requirements and fuel economy
No Description Available.
Aerodynamic and hydrodynamic tests of a family of models of flying-boat hulls derived from a streamline body: NACA model 84 series
Report presenting a series of related flying-boat hull forms with various combinations of aerodynamic and hydrodynamic requirements that were tested in an NACA tank and high-speed tunnel. Effects explored included varying the height of the bow, varying the height of the stern, increasing the angle of dead rise at the bow, decreasing the angle of dead rise on the afterbody, increasing the depth of step, increasing the angle of afterbody keel, adding chine flare, adding a third planing surface, and rounded chines at the bow.
Aerodynamic and hydrodynamic tests of a family of models of flying hulls derived from a streamline body -- NACA model 84 series
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.
Aerodynamic characteristics and flap loads of perforated double split flaps on a rectangular NACA 23012 airfoil
From Introduction: "The results of the load tests and some additional aerodynamic characteristics of perforated double split flaps on a rectangular NACA 23012 airfoil are given in the present report."
Air-flow surveys in the region of the tail surfaces of a single-engine airplane equipped with dual-rotating propellers
From Summary: "Surveys of the air flow in the region of the tail surfaces of a single-engine pursuit-type airplane equipped with dual-rotating propellers are presented."
Altitude rating of electrical apparatus
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."
Analysis of Oil Production in the Near-Depleted Mexia-Powell Fault-Line Fields of Texas
Report issued by the U.S. Bureau of Mines on the oil fields located near the Mexia-Powell fault line in Texas. Properties of the oil fields, including geology and oil production, are presented. This report includes tables, graphs, maps, and illustrations.
The analysis of strains indicated by multiple-strand resistance-type wire strain gages used as rosettes
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."
Analysis of the High-Altitude Cooling of the Ranger SGV-770 D-4 Engine in the Bell XP-77 Airplane
No abstract available.
Analysis of wind-tunnel stability and control tests in terms of flying qualities in full-scale airplanes
From Summary: "The analysis of results of wind-tunnel stability and control tests of powered airplane models in terms of the flying qualities of full-scale airplanes is advocated. In order to indicate the topics upon which comments are considered desirable in the report of a wind-tunnel stability and control investigation and to demonstrate the nature of the suggested analysis, the present NACA flying-qualities requirements are discussed in relation to wind-tunnel tests. General procedures for the estimation of flying qualities from wind-tunnel tests are outlined."
Analysis of wind-tunnel stability and control tests in terms of flying qualities of full-scale airplanes
From Introduction: "The purpose of this paper is to outline a suggested form of presentation of the results of a stability and control investigation in terms of flying qualities as defined in reference 1 and to systematize and review briefly the analytical work required for this type of presentation. No effort is made to specify definite test procedures."
Annual Report of Research and Technologic Work on Coal: Fiscal Year 1942
Report issued by the U.S. Bureau of Mines discussing studies over the research and technology of coal during 1942. As stated in the introduction, "the annual reports of the research and technologic investigations conducted by the Bureau of Mines on the occurrence, properties, mining, preparation, and uses of coal, of which the present report is the seventh, are intended to be brief summaries of progress" (p. 4). This report includes tables, illustrations, and photographs.
Antiknock effectiveness of xylidines in small-scale engines
From Introduction: "The data presented in this report are part of a general program to determine the effects of xylidines on the knock-limited performance of currently used aviation fuels."
An approximate method of shear-lag analysis for beams loaded at right angles to the plane of symmetry of the cross section
Report discussing strain measurements made on a box beam of triangular cross section and on two beams of D-section under transverse bending. Information about the arrangement of the beams and experimental and calculated stresses for different boxes.
Bearing strengths of bare and alclad XA75S-T and 24S-T81 aluminum alloy sheet
From Introduction: "A report was recently issued covering an investigation of the bearing properties of the wrought aluminum alloys commonly used in aircraft construction (reference 1). Since this work was undertaken, two new materials, XA75S-T and 24S-T81, have been developed to the commercial stage for aircraft use. The objection of this investigation was to determine the bearing yield and ultimate strengths of these new materials in the form of bare and alclad sheet."
Bearing strengths of some wrought-aluminum alloys
From Introduction: "Although a number of investigations of the bearing strength of aluminum alloys have been made, the problem remains one of considerable interest to the aircraft industry. For this reason it has seemed advisable to make additional tests of the commonly used aircraft alloys in an effort to establish a better basis for the selection of allowable bearing values. Current design practice does not recognize the effect of edge distance upon bearing strengths, and for this reason edge distance was one of the principal variables considered in this investigation. The increasing emphasis being placed upon permanent set limitations makes it essential that more information on bearing yield phenomena be obtained."
Bearing tests of magnesium-alloy sheet
From Summary: "Bearing tests of AM-3S, AM-52S, and AM-C57S magnesium-alloy sheet in various thicknesses and tempers were made. Bearing yield and ultimate strengths were determined and compared for various edge distances and for various ratios of loading-pin diameter to sheet thickness. Tensile strengths were determined and ratios of average bearing yield and ultimate strength to tensile strength are given."
The belt method for measuring pressure distribution
No Description Available.
The Biologic Effects of Radiation ; Training Program Lecture Notes
The following report provides data taken from investigations on radiation and the different biologic effects on it.
Briquetting Subbituminous Coal
Report issued by the Bureau of Mines over briquetting of coal for development of more effective fuel. Materials, equipment, and processes are discussed. This report includes tables, illustrations, and photographs.
Byproduct Coke-Oven Tests of Washington Coals
Report issued by the U.S. Bureau of Mines on the coking-coal testing done on Washington coal. Descriptions of the testing, and properties of the coals tested are presented. This report includes tables, and photographs.
Calculated and measured turning performance of a Navy F2A-3 airplane as affected by the use of flaps
Report presenting results of flight tests to determine the turning performance of a Navy F2A-3 airplane over a range of speeds for three flap deflections at two altitudes. The results are correlated with an analytical study of turning performance in which the effect of thrust on maximum lift coefficient was considered.
Certain mechanical strength properties of aluminum alloys 25S-T and X76S-T
No Description Available.
Characteristics of an NACA 66, S-209 section hydrofoil at several depths
Report presenting an investigation of the force characteristics of single hydrofoils in order to help with preliminary hydrofoil design.
Charts for calculation of the critical stress for local instability of columns with I-, Z-, channel and rectangular-tube section
Report presenting charts for the calculation of the critical stress for local instability of columns with I-, Z-, channel-, and rectangular-tube sections. An experimental curve is included for use in taking into account the effect of stresses above the elastic range on 24S-T aluminum alloy elasticity.
Coke from Low-Ash Appalachian Coals for Carbon Electrodes in Aluminum Industry with a Chapter on Comparison of Results Obtained by Trent Process for Cleaning Coal with Those by Float-and-Sink Methods
Report issued by the U.S. Bureau of Mines on testing conducted on coking coal samples for carbon electrode use in aluminum production. The testing methods, and results are presented. This report includes tables.
A comparative study of the effect of wing flutter shape on the critical flutter speed
No Description Available.
Comparative Yields of Light Oil, Tar, and Constituents from Carbonization Tests at 800 Degrees, 900 Degrees, and 1,000 Degrees Celsius
Report issued by the U.S. Bureau of Mines on testing done on a variety of American coals collected from 32 coal beds across the country. The carbonizing properties of samples tested at 3 different temperatures are presented. This report includes tables, and graphs.
A comparison at high speed of the aerodynamic merits of models of medium bombers having thickened wing roots and having wings with nacelles
No Description Available.
Comparison of various methods for computing drag from wake surveys
No Description Available.
Construction of wire strain gages for engine application
No Description Available.
Correlation of single-cylinder cooling tests of a Pratt and Whitney R-2800-21 engine cylinder with wind-tunnel tests of a Pratt and Whitney R-2800-27 engine
No Description Available.
A correlation of the dimensions, proportions, and loadings of existing seaplane floats and flying boat hulls
No Description Available.
The Coso Quicksilver District, Inyo County, California
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.
The Coupling of Flexural Propeller Vibrations with the Torsional Crankshaft Vibrations
The exact mathematical treatment of the problem is possible by replacing the propeller blade by a homogeneous prismatic rod. Conclusions can them be drawn as to the behavior of an actual propeller, since tests on propeller blades have indicated a qualitative agreement with the homogeneous rod. The natural frequencies are determined and the stressing of the systems under the various vibration modes are discussed.
Critical compressive stress for curved sheet supported along all edges and elastically restrained against rotation along the unloaded edges
From Summary: "A formula is given for the critical compressive stress for slightly curved sheet with equal elastic restraints against rotation along the unloaded edges. The theory of small deflections is used and the formula reduces to that given by Timoshenko for the case of simply-supported edges. For larger curvatures, a modification of Redshaw's formula to include the effect of edge restraint is suggested."
Critical shear stress of an infinitely long flat plate with equal elastic restraints against rotation along the parallel edges
No Description Available.
Critical stress for an infinitely long flat plate with elastically restrained edges under combined shear and direct stress
No Description Available.
Critical stresses for plates
Report presenting the basic methods of theoretically calculating the critical stress for plates with elastically restrained edges. Design charts for various types of sections and columns and critical stress for flat plates and curved sheets are provided.
Data on buckling strength of curved sheet in compression
No Description Available.
Derivation of charts for determining the horizontal tail load variation with any elevator motion
The equations relating the wing and tail loads are derived for a unit elevator displacement. These equations are then converted into a nondimensional form and charts are given by which the wing- and tail-load-increment variation may be determined under dynamic conditions for any type of elevator motion and for various degrees of airplane stability. In order to illustrate the use of the charts, several examples are included in which the wing and tail loads are evaluated for a number of types of elevator motion. Methods are given for determining the necessary derivatives from results of wind-tunnel tests when such tests are available.
Derivation of charts for determining the horizontal tail load variation with any elevator motion
No Description Available.
Description of stress-strain curves by three parameters
A simple formula is suggested for describing the stress-strain curve in terms of three parameters; namely, Young's modulus and two secant yield strengths. Dimensionless charts are derived from this formula for determining the stress-strain curve, the tangent modulus, and the reduced modulus of a material for which these three parameters are given. Comparison with the tensile and compressive data on aluminum-alloy, stainless-steel, and carbon-steel sheet in NACA Technical Note No. 840 indicates that the formula is adequate for most of these materials. The formula does not describe the behavior of alclad sheet, which shows a marked change in slope at low stress. It seems probable that more than three parameters will be necessary to represent such stress-strain curves adequately.
Design criterions for the dimensions of the forebody of a long-range flying boat
No Description Available.
Design, selection, and installation of aircraft heat exchangers
Report presenting a survey of aircraft heat exchangers in three parts: design, selection, and installation. Appendices give the physical properties of air, properties of standard atmosphere as defined by the Navy, Army, and NACA, and an impact-pressure chart.
Determination of Flight Paths of an SBD-1 Airplane in Simulated Diving Attacks, Special Report
An investigation has been made to determine the motions of and the flight paths describe by a Navy dive-bombing airplane in simulated diving attacks. The data necessary to evaluate these items, with the exception of the atmospheric wind data, were obtained from automatic recording instruments installed entirely within the airplane. The atmospheric wind data were obtained from the ground by the balloon-theodolite method. The results of typical dives at various dive angles are presented in the form of time histories of the motion of the airplane as well as flight paths calculated with respect to still air and with respect to the ground.
Determination of general relations for the behavior of turbulent boundary layers
From Summary: "An analysis has been made of a considerable amount of data for turbulent boundary layers along wings and bodies of various shapes in order to determine the fundamental variables that control the development of turbulent boundary layers. It was found that the type of velocity distribution in the boundary layer could be expressed in terms of a single parameter. This parameter was chosen as the ratio of the displacement thickness to the momentum thickness of the boundary layer. The variables that control the development of the turbulent boundary layer apparently are: (1) the ratio of the nondimensional pressure gradient, expressed in terms of the local dynamic pressure outside the boundary layer and boundary-layer thickness, to the local skin-friction coefficient and (2) the shape of the boundary layer. An empirical equation has been developed in terms of these variables that, when used with the momentum equation and the skin-friction relation, makes it possible to trace the development of the turbulent boundary layer to the separation point."