Serial/Series Title
NACA Wartime Reports
69
NACA Technical Notes
49
NACA Technical Memorandums
36
NACA Advanced Restricted Reports
30
NACA Technical Reports
26
NACA Advanced Confidential Reports
21
NACA Memorandum Reports
19
NACA Special Reports
17
United States Bureau of Mines Reports
17
U.S. Geological Survey bulletin
14
28 More
States
238 Matching Results
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Shear Lag in Corrugated Sheets Used for the Chord Member of a Box Beam
"The problem of the distribution of normal stress across a wide corrugated sheet used as the chord of a box-beam-like structure is investigated theoretically and experimentally. Expressions are developed giving the stress distribution in beams, symmetrical or unsymmetrical, about a plane passed spanwise through the center of the sheet. The experiments were arranged to insure bending without torsion and surveys of the normal stresses were made by means of mechanical and electrical strain gages" (p. 1).
Date:
January 1941
Creator:
Newell, Joseph S. & Reissner, Eric
System:
The UNT Digital Library
Stresses and Deflections in Thin Shells and Curved Plates Due to Concentrated and Variously Distributed Loading
Note presenting tests made on cylindrical and spherical shells to determine the local stresses and deflections produced by concentrated and variously distributed loading. The results are correlated with those of earlier experiments, and empirical formulas based on the data are proposed. Data are presented on the effect of severe prestressing on stiffness and on the efficiency of welded lugs of various forms in transmitting a load to a thin shell without producing excessive local stresses.
Date:
May 1941
Creator:
Roark, Raymond J.
System:
The UNT Digital Library
The End-Plate Effect of a Horizontal-Tail Surface on Vertical Tail Surface
Note presenting the end-plate effect of the horizontal-tail surface on the vertical-tail surface as theoretically studied by derivation of the flow corresponding to the condition of minimum induced drag and by solution of the usual lifting-line equations. The results obtained by the two methods were considerably different, indicated that the condition derived is not a close approximation to the actual condition.
Date:
February 1941
Creator:
Katzoff, S. & Mutterperl, William
System:
The UNT Digital Library
Compression tests of some 17S-T aluminum-alloy specimens of I cross section
Report presenting testing of specimens cut from a specially extruded I-beam of 17S-T aluminum alloy with one flange wider than the other under axial compression. Only the two longest specimens failed as columns, while the shorter ones failed by local buckling. The agreement between experimental and calculated values of critical stress can be improved by considering the effect of restraint at the loaded edges of the web and adopting a more accurate buckling treatment beyond the elastic range.
Date:
March 1941
Creator:
Hill, H. N.
System:
The UNT Digital Library
Effect of Alternately High and Low Repeated Stresses Upon the Fatigue Strength of 25S-T Aluminum Alloy
"Fatigue tests were made on one lot of 3/4 inch diameter rolled-and-drawn 25S-T aluminum-alloy rod normal in composition and tensile properties. The specimens were tested at 3500 cycles per second in a rotating-beam fatigue test machine. Tests were made for three ratios (20:1, 50:1, and 200:1) of the number of cycles applied at low stress to the number applied at high stress. In general, failure occurred when the number of cycles at either the low or the high stress approached the ordinary fatigue curve for the material, regardless of the sequence in which the stresses were applied" (p. 1).
Date:
January 1941
Creator:
Stickley, G. W.
System:
The UNT Digital Library
Two-Stage Supercharging
"The arrangement of the parts and the installation and control problems of the two-stage mechanically driven superchargers for aircraft engines are discussed. Unless an entirely new form of supercharging is developed, there will be a definite need for a two-stage centrifugal supercharger. It is shown that the two-stage mechanically driven supercharger itself is a comparatively simple device; the complications arise from the addition of inter-coolers and controls" (p. 1).
Date:
February 1941
Creator:
Buck, Richard S.
System:
The UNT Digital Library
Effect of several supercharger control methods on engine performance
Report presenting an analytical comparison of a variety of superchargers using the same hypothetical engine, which include a single-speed, a two-speed, and a variable-speed DVL centrifugal supercharger, the Szydlowski-Planiol supercharger with a single-speed and a two-speed transmission, and a turbosupercharger.
Date:
February 1941
Creator:
Wasielewski, Eugene W. & King, J. Austin
System:
The UNT Digital Library
Tests on Stiffened Circular Cylinders
"Compressive tests were made of two series of stiffened circular cylindrical shells under axial load. All the shells were 16 inches in diameter by 24 inches in length and were made of aluminum-alloy sheet curved to the proper radius and welded with one longitudinal weld. The ratios of diameter to thickness of shell wall in the two series of specimens were 258 and 572" (p. 1).
Date:
March 1941
Creator:
Holt, Marshall
System:
The UNT Digital Library
Tests of Round and Flat Spoilers on a Tapered Wing in the NACA 19-Foot Pressure Wind Tunnel
"Several arrangements of round and flat spanwise spoilers attached to the upper surface of a tapered wing were tested in the NACA 19-foot pressure wind tunnel to determine the most effective type, location, and size of spoiler necessary to reduce greatly the lift on the wings of large flying boats when moored. The effect of the various spoilers on the lift, the drag, and the pitching-moment characteristics of the tapered wing was measured over a range of angles of attack from zero to maximum lift. The most effective type of spoiler was found to be the flat type with no space between it and the wing surface" (p. 1).
Date:
March 1941
Creator:
Wenzinger, Carl J. & Bowen, John D.
System:
The UNT Digital Library
Tests of a gust-alleviating wing in the gust tunnel
"Tests were made in the NACA gust tunnel to determine the effectiveness of a torsionally flexible wing with the torsion axis ahead of the locus of the section aerodynamic centers in reducing airplane accelerations due to atmospheric gusts. For three gust shapes, a series of flights was made with the airplane model equipped with either a torsionally flexible or a rigid wing. The results indicated that the torsionally flexible wing reduced the maximum acceleration increment 5 percent for the sharp-edge gust and about 17 percent for gust shapes with gradient distances of 6.8 and 15 chord lengths" (p. 1).
Date:
April 1941
Creator:
Shufflebarger, C. C.
System:
The UNT Digital Library
Wind-Tunnel Investigation of Several Factors Affecting the Performance of a High-Speed Pursuit Airplane With Air-Cooled Radial Engine
Report details an investigation into various potential improvements and modifications to pursuit airplanes. NACA low-drag airfoil sections and their use for reducing drag and increasing compressibility speeds were examined. Other items covered include the propeller slipstream, high-speed cowling arrangement, and placement of wing guns.
Date:
November 1941
Creator:
Wenzinger, Carl J.
System:
The UNT Digital Library
Some effects of rainfall on flight of airplanes and on instrument indications
"Several possible effects of heavy rain on the aerodynamic performance of an airplane and of heavy rain and associated atmospheric phenomena on the indications of flight instruments are briefly considered. It is concluded that the effects of heavy rain on the performance of an airplane are not so great as to force the airplane down from moderate altitudes. Serious malfunctioning of the air-speed indicator may occur, however, as a result of flooding of the pitot-static head and subsequent accumulation of water in the air-speed pressure line" (p. 1).
Date:
April 1941
Creator:
Rhode, Richard V.
System:
The UNT Digital Library
Effect of Aging on Mechanical Properties of Aluminum-Alloy Rivets
"Curves and tabular data present the results of strength tests made during and after 2 1/2 years of aging on rivets and rivet wire of 3/16-inch nominal diameter. The specimens were of aluminum alloy: 24S, 17S, and A17S of the duralumin type and 53S of the magnesium-silicide type" (p. 1).
Date:
April 1941
Creator:
Roop, Frederick C.
System:
The UNT Digital Library
Model Tests of a Wing-Duct System for Auxiliary Air Supply
Report discusses the design of a cooling system developed for a Pratt & Whitney H-2800 engine equipped with a two-stage supercharger. The wing-duct system was newly developed and was determined to be a valuable method for cooling engine auxiliaries by combining simplicity with low drag and excellent cooling capabilities.
Date:
January 1941
Creator:
Bierman, David & Corson, Blake W., Jr.
System:
The UNT Digital Library
Spin Tests of a Low-Wing Monoplane to Investigate Scale Effect in the Model Test Range
"Concurrent tests were performed on a 1/16 and a 1/20 scale model (wing spans of 2.64 and 2.11 ft. respectively) of a modern low wing monoplane in the NACA 15 foot free-spinning wind tunnel. Results are presented in the form of charts that afford a direct comparison between the spins of the two models for a number of different conditions. Qualitatively, the same characteristic effects of control disposition, mass distribution, and dimensional modifications were indicated by both models" (p. 1).
Date:
May 1941
Creator:
Donlan, Charles J.
System:
The UNT Digital Library
Methods of analyzing wind-tunnel data for dynamic flight conditions
The effects of power on the stability and the control characteristics of an airplane are discussed and methods of analysis are given for evaluating certain dynamic characteristics of the airplane that are not directly discernible from wind tunnel tests alone. Data are presented to show how the characteristics of a model tested in a wind tunnel are affected by power. The response of an airplane to a rolling and a yawing disturbance is discussed, particularly in regard to changes in wing dihedral and fin area. Solutions of the lateral equations of motion are given in a form suitable for direct computations. An approximate formula is developed that permits the rapid estimation of the accelerations produced during pull-up maneuvers involving abrupt elevator deflections.
Date:
July 22, 1941
Creator:
Donlan, C. J. & Recant, I. G.
System:
The UNT Digital Library
Requirements for Satisfactory Flying Qualities of Airplanes
Report discusses the results of an analysis of available data to determine what measured characteristics are significant in defining satisfactory flying qualities, what characteristics are reasonable to require of an airplane, and what influence the various design features have on the observed flying qualities.
Date:
March 24, 1941
Creator:
Gilruth, R. R.
System:
The UNT Digital Library
A study by high-speed photography of combustion and knock in a spark-ignition engine
"The study of combustion in a spark-ignition engine given in Technical Report no. 704 has been continued. The investigation was made with the NACA high-speed motion-picture camera and the NACA optical engine indicator. The camera operates at the rate of 40,000 photographs a second and makes possible the study of phenomena occurring in time intervals as short as 0.000025 second. Photographs are presented of combustion without knock and with both light and heavy knocks, the end zone of combustion being within the field of view" (p. 15).
Date:
December 9, 1941
Creator:
Miller, Cearcy D.
System:
The UNT Digital Library
On the Use of Residue Theory for Treating the Subsonic Flow of a Compressible Fluid
"A new mathematical technique, due to Milne-Thomson, is used to obtain an improved form of the method of Poggi for calculating the effect of compressibility on the subsonic flow past an obstacle. By means of this new method, the difficult surface integrals of the original Poggi method can be replaced by line integrals. These line integrals are then solved by the use of residue theory. In this way an equation is obtained giving the second-order effect of compressibility on the velocity of the fluid" (p. 39).
Date:
September 8, 1941
Creator:
Kaplan, Carl
System:
The UNT Digital Library
Test of single-stage axial-flow fan
"A single-stage axial fan was built and tested in the shop of the propeller-research tunnel of the NACA. The fan comprised a simple 24-blade rotor having a diameter of 21 inches and a solidity of 0.86 and a set of 37 contravanes having a solidity of 1.33. The rotor was driven by a 25-horsepower motor capable of rotating at a speed of 3600 r.p.m. The fan was tested for volume, pressure, and efficiency over a range of delivery pressures and volumes for a wide range of contravane and blade-angle settings" (p. 49).
Date:
September 22, 1941
Creator:
Bell, E. Barton
System:
The UNT Digital Library
Determination of optimum plan forms for control surfaces
Solutions found for a range of airfoil plan forms indicate that, regardless of the characteristics of the tail surface, the chord of the rudder or of the elevator should be very nearly constant over its span. The optimum ailerons are also of a characteristic shape, varying little with the plan form of the wing.
Date:
January 30, 1941
Creator:
Jones, Robert T. & Cohen, Doris
System:
The UNT Digital Library
Pressure distribution over an NACA 23012 airfoil with a fixed slot and a slotted flap
Report presents the results of a pressure-distribution investigation conducted in the Langley Memorial Aeronautical Laboratory 7 by 10-foot wind tunnel to determine the air loads on an NACA 23012 airfoil in combination with a fixed leading-edge slot and a slotted flap. Pressures were measured over the upper and lower surfaces of the component parts of the combination for several angles of attack and at several flap settings. The data, presented as pressure diagrams and graphs of section coefficients, are applicable to rib, slat, and flap designs for the combination.
Date:
July 30, 1941
Creator:
Harris, Thomas A. & Lowry, John G.
System:
The UNT Digital Library
Critical Compressive Stress for Outstanding Flanges
A chart is presented for the values of the coefficient in the formula for the critical compressive stress at which buckling may be expected to occur in outstanding flanges. These flanges are flat rectangular plates supported along the loaded edges, supported and elastically restrained along one unloaded edge, and free along the other unloaded edge. The mathematical derivations of the formulas required for construction of the chart are given.
Date:
March 14, 1941
Creator:
Lundquist, Eugene E. & Stowell, Elbridge Z.
System:
The UNT Digital Library
Critical Compressive Stress for Flat Rectangular Plates Supported Along All Edges and Elastically Restrained Against Rotation along the Unloaded Edges
A chart is presented for the values of the coefficient in the formula for the critical compressive stress at which buckling may be expected to occur in flat rectangular plates supported along all edges and, in addition, elastically restrained against rotation along the unloaded edges. The mathematical derivations of the formulas required in the construction of the chart are given.
Date:
March 8, 1941
Creator:
Lundquist, Eugene E. & Stowell, Elbridge Z.
System:
The UNT Digital Library