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 Decade: 1940-1949
 Year: 1943
 Collection: National Advisory Committee for Aeronautics Collection
Adaptor for measuring principal strains with Tuckerman strain gage
An adapter is described 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. digital.library.unt.edu/ark:/67531/metadc56629/
Additional design charts relating to the stalling of tapered wings
No Description digital.library.unt.edu/ark:/67531/metadc61269/
The advantages of uniform fuel distribution for air-cooled engines from considerations of cooling requirements and fuel economy
No Description digital.library.unt.edu/ark:/67531/metadc61935/
Aerodynamic and hydrodynamic tests of a family of models of flying-boat hulls derived from a streamline body : NACA model 84 series
No Description digital.library.unt.edu/ark:/67531/metadc61711/
Aerodynamic and hydrodynamic tests of a family of models of flying hulls derived from a streamline body -- NACA model 84 series
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. digital.library.unt.edu/ark:/67531/metadc60031/
Aerodynamic characteristics and flap loads of perforated double split flaps on a rectangular NACA 23012 airfoil
No Description digital.library.unt.edu/ark:/67531/metadc61464/
Air-flow surveys in the region of the tail surfaces of a single-engine airplane equipped with dual-rotating propellers
No Description digital.library.unt.edu/ark:/67531/metadc61168/
Altitude rating of electrical apparatus
No Description digital.library.unt.edu/ark:/67531/metadc62410/
Analysis of heat and compressibility effects in internal flow systems and high-speed tests of a ram-jet system
An analysis has been made by the NACA of the effects of heat and compressibility in the flow through the internal systems of aircraft. Equations and charts are developed whereby the flow characteristics at key stations in a typical internal system may be readily obtained. digital.library.unt.edu/ark:/67531/metadc60041/
The analysis of strains indicated by multiple-strand resistance-type wire strain gages used as rosettes
No Description digital.library.unt.edu/ark:/67531/metadc62612/
Analysis of the High-Altitude Cooling of the Ranger SGV-770 D-4 Engine in the Bell XP-77 Airplane
No abstract available. digital.library.unt.edu/ark:/67531/metadc53580/
Analysis of wind-tunnel stability and control tests in terms of flying qualities in full-scale airplanes
No Description digital.library.unt.edu/ark:/67531/metadc279513/
Antiknock effectiveness of xylidines in small-scale engines
No Description digital.library.unt.edu/ark:/67531/metadc62346/
An approximate method of shear-lag analysis for beams loaded at right angles to the plane of symmetry of the cross section
No Description digital.library.unt.edu/ark:/67531/metadc61305/
Bearing strengths of bare and alclad XA75S-T and 24S-T81 aluminum alloy sheet
No Description digital.library.unt.edu/ark:/67531/metadc64909/
Bearing strengths of some wrought-aluminum alloys
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. The object of this investigation was to determine bearing yield and ultimate strengths of the following aluminum alloy products: 17S-T, 24S-T, Alclad 24S-T, 24S-RT, 52S-0, 52S-1/2H, 52S-H, 53S-T, and 61S-T extrusions. Ratios of these bearing properties to tensile properties were also determined. digital.library.unt.edu/ark:/67531/metadc54692/
Bearing tests of magnesium-alloy sheet
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 results of the tests indicated that ultimate bearing strengths increased with edge distances up to 1.5 to 2 times the diameter of the loading pin; that ultimate bearing strengths are a function of the ratio of pin diameter to sheet thickness; and that these properties are effected only slightly by increases in edge distance greater than 1.5 diameters. digital.library.unt.edu/ark:/67531/metadc54681/
The belt method for measuring pressure distribution
No Description digital.library.unt.edu/ark:/67531/metadc62095/
Calculated and measured turning performance of a Navy F2A-3 airplane as affected by the use of flaps
No Description digital.library.unt.edu/ark:/67531/metadc61133/
Certain mechanical strength properties of aluminum alloys 25S-T and X76S-T
No Description digital.library.unt.edu/ark:/67531/metadc54731/
Characteristics of an NACA 66, S-209 section hydrofoil at several depths
No Description digital.library.unt.edu/ark:/67531/metadc61781/
Charts for calculation of the critical stress for local instability of columns with I-, Z-, channel and rectangular-tube section
No Description digital.library.unt.edu/ark:/67531/metadc62206/
A comparative study of the effect of wing flutter shape on the critical flutter speed
No Description digital.library.unt.edu/ark:/67531/metadc61272/
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 digital.library.unt.edu/ark:/67531/metadc61167/
Comparison of various methods for computing drag from wake surveys
No Description digital.library.unt.edu/ark:/67531/metadc60887/
Construction of wire strain gages for engine application
No Description digital.library.unt.edu/ark:/67531/metadc62424/
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 digital.library.unt.edu/ark:/67531/metadc61981/
A correlation of the dimensions, proportions, and loadings of existing seaplane floats and flying boat hulls
No Description digital.library.unt.edu/ark:/67531/metadc61755/
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. digital.library.unt.edu/ark:/67531/metadc64419/
Critical compressive stress for curved sheet supported along all edges and elastically restrained against rotation along the unloaded edges
No Description digital.library.unt.edu/ark:/67531/metadc60915/
Critical shear stress of an infinitely long flat plate with equal elastic restraints against rotation along the parallel edges
No Description digital.library.unt.edu/ark:/67531/metadc61474/
Critical stress for an infinitely long flat plate with elastically restrained edges under combined shear and direct stress
No Description digital.library.unt.edu/ark:/67531/metadc60918/
Critical stresses for plates
No Description digital.library.unt.edu/ark:/67531/metadc62204/
Data on buckling strength of curved sheet in compression
No Description digital.library.unt.edu/ark:/67531/metadc60917/
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. digital.library.unt.edu/ark:/67531/metadc60024/
Derivation of charts for determining the horizontal tail load variation with any elevator motion
No Description digital.library.unt.edu/ark:/67531/metadc279445/
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. digital.library.unt.edu/ark:/67531/metadc54697/
Design criterions for the dimensions of the forebody of a long-range flying boat
No Description digital.library.unt.edu/ark:/67531/metadc60913/
Design, selection, and installation of aircraft heat exchangers
No Description digital.library.unt.edu/ark:/67531/metadc61934/
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. digital.library.unt.edu/ark:/67531/metadc65195/
Determination of general relations for the behavior of turbulent boundary layers
No Description digital.library.unt.edu/ark:/67531/metadc279609/
Determination of general relations for the behavior of turbulent boundary layers
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. digital.library.unt.edu/ark:/67531/metadc60040/
Determination of the damping moment in yawing for tapered wings with partial-span flaps
No Description digital.library.unt.edu/ark:/67531/metadc61258/
Determination of the Mass Moments and Radii of Inertia of the Sections of a Tapered Wing and the Center-of-Gravity Line along the Wing Span
For computing the critical flutter velocity of a wing among the data required are the position of the line of centers of gravity of the wing sections along the span and the mass moments and radii of inertia of any section of the wing about the axis passing through the center of gravity of the section. A sufficiently detailed computation of these magnitudes even if the weights of all the wing elements are known, requires a great deal of time expenditure. Thus a rapid competent worker would require from 70 to 100 hours for the preceding computations for one wing only, while hundreds of hours would be required if all the weights were included. With the aid of the formulas derived in the present paper, the preceding work can be performed with a degree of accuracy sufficient for practical purposes in from one to two hours, the only required data being the geometric dimensions of the outer wing (tapered part), the position of its longerons, the total weight of the outer wing, and the approximate weight of the longerons, The entire material presented in this paper is applicable mainly to wings of longeron construction of the CAHI type and investigations are therefore being conducted by CAHI for the derivation of formulas for the determination of the preceding data for wings of other types. digital.library.unt.edu/ark:/67531/metadc64422/
Development of thermal ice-prevention equipment for the B-17F airplane
No Description digital.library.unt.edu/ark:/67531/metadc61807/
Development of thermal ice-prevention equipment for the B-24D airplane
No Description digital.library.unt.edu/ark:/67531/metadc61804/
Ditching tests with 1/10-size model of the Army A-20A airplane I : calm-water tests in NACA tank no.2
No Description digital.library.unt.edu/ark:/67531/metadc279645/
Drag Measurements of a Protruding.50-Caliber Machine Gun with Barrel Jacket Removed
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. digital.library.unt.edu/ark:/67531/metadc62427/
The effect of altitude on bomber performance
No Description digital.library.unt.edu/ark:/67531/metadc60853/
The effect of altitude on cooling
No Description digital.library.unt.edu/ark:/67531/metadc279422/
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