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Description of Stress-Strain Curves by Three Parameters

Description: "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… more
Date: July 1943
Creator: Ramberg, Walter & Osgood, William R.
Partner: UNT Libraries Government Documents Department
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Round Heat-Treated Chromium-Molybdenum-Steel Tubing Under Combined Loads

Description: "The results of tests of round heat-treated chromium-molybdenum-steel tubing are presented. Tests were made on tubing under axial load, bending load, torsional load, combined bending and axial load, combined bending and torsional load, and combined axial, bending, and torsional load. Tensile and compressive tests were made to determine the properties of the material. Formulas are given for the evaluation of the maximum strength of this steel tubing under individual or combined loads" (p. 1).
Date: July 1943
Creator: Osgood, William R.
Partner: UNT Libraries Government Documents Department
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Column Strength of Magnesium Alloy AM-57S

Description: Tests were made to determine the column strength of extruded magnesium alloy AM-57S. Column specimens were tested with round ends and with flat ends. It was found that the compressive properties should be used in computations for column strengths rather than the tensile properties because the compressive yield strength was approximately one-half the tensile yield strength. A formula for the column strength of magnesium alloy AM-57S is given.
Date: July 1943
Creator: Holt, M.
Partner: UNT Libraries Government Documents Department
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Effect of Rivet Pitch Upon the Fatigue Strength of Single-Row Riveted Joints of 0.025- to 0.025-Inch 24S-T Alclad

Description: "S-N curves at the range ratio of 0.2 were experimentally obtained for each of the following values of rivet pitch P as used in a single-row lap joint of 0.025- to 0.025-inch 24S-T alclad with one-eight AN430 round-head rivets: p=0.5, 0.75, 1.0, 1.5. Families of constant rivet pitch curves, which define the fatigue life for specimens studied, were developed. Curves showing the variation of the effective stress concentration factor in fatigue with rivet pitch and maximum load per rivet were also… more
Date: July 1943
Creator: Seliger, Victor
Partner: UNT Libraries Government Documents Department
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NACA Procedure for Flight Tests of Aileron Characteristics of Airplanes

Description: Report describes the standard procedure that NACA used for evaluating the aileron characteristics of airplanes. The variables measured in the testing are rolling velocity, aileron positions, aileron stick forces or tangential wheel force, indicated airspeed, altitude, free-air temperature, and rudder position. The step-by-step flight procedure is described and information regarding evaluation of the control data and general suggestions is included.
Date: July 1943
Creator: Johnson, Harold I.
Partner: UNT Libraries Government Documents Department
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Wind-tunnel tests of four full-scale seaplane floats

Description: Report presenting wind tunnel testing of four full-scale seaplane floats to determine the aerodynamic characteristics of the floats and to evaluate several drag-reducing refinements. Four floats were investigated; two differed only in external details like flush rivets, while one was the type used on twin-float installations. The variation of lift, drag, and pitching moment with pitch angle are presented for each float.
Date: July 1943
Creator: Conway, Robert N. & Maynard, Julian D.
Partner: UNT Libraries Government Documents Department
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Wind-tunnel investigation of control-surface characteristics 13: various flap overhangs used with a 30-percent-chord flap in an NACA 66-009 airfoil

Description: Report presenting force tests in two-dimensional flow made on an NACA 66-009 airfoil with a flap having a chord 30 percent of the airfoil chord and a tab having a chord 20 percent of the flap chord. A plain flap and flaps having overhangs of 35 and 50 percent of the flap chord were tested with two gap variations: sealed and unsealed. Results regarding lift, flap hinge moments, pitching moments, drag, and tab characteristics are provided.
Date: July 1943
Creator: Gillis, Clarence L.
Partner: UNT Libraries Government Documents Department
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Selection of Oil Coolers to Avoid Congealing

Description: Report presenting a study of oil coolers, especially in regards to three factors: the congealing tendency of the cooler, the power cost chargeable to the installation, and the performance characteristics of the oil cooler in operation at altitude.
Date: July 1943
Creator: Martin, Dennis J.
Partner: UNT Libraries Government Documents Department
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Knocking Tendency of an Air-Cooled Aircraft-Engine Cylinder With One and With Two Spark Plugs

Description: Report presenting tests conducted with an air-cooled aircraft-engine cylinder to determine the effect on the knocking tendency of cutting out one spark plug when the engine is operating at or near the knock point with two spark plugs firing. The results indicate that cutting out one spark plug will not lead to knock but will actually stop or decrease knock that is occurring with both spark plugs firing.
Date: July 1943
Creator: Spencer, R. C. & Jones, A. W.
Partner: UNT Libraries Government Documents Department
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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 m… more
Date: July 20, 1943
Creator: Campbell, John P. & Seacord, Charles L., Jr.
Partner: UNT Libraries Government Documents Department
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Design, selection, and installation of aircraft heat exchangers

Description: 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.
Date: July 1943
Creator: Wood, George P. & Brevoort, Maurice J.
Partner: UNT Libraries Government Documents Department
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Relation of Preignition and Knock to Allowable Engine Temperatures

Description: "The results are given of an investigation of some of the limitations that now prevent increases in the temperature level of engine cylinder heads, and a review of previous work in the field is included to supplement these results. Attention was given, in particular, to the effects of fuel knock and surface ignition on cylinder temperatures and the effects of cylinder temperatures on performance. Data were obtained from a Wright C9GC air-cooled cylinder and from a Lycoming O-1230 liquid-cooled … more
Date: July 1943
Creator: Biermann, Arnold E. & Corrington, Lester C.
Partner: UNT Libraries Government Documents Department
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Investigation of Methods of Reducing the Temperature Variation Among Cylinders on Air-Cooled Aircraft Engines

Description: Report presenting testing to determine methods for reducing the temperatures of the hot cylinders on air-cooled aircraft engines. A Pratt & Whitney R-1830-43, 14-cylinder engine used for the tests. Results regarding the cooling-air ducts, mixture-enriching tests, additional cooling area, baffle modifications, and an application of the information are provided.
Date: July 1943
Creator: Mueller, William A.
Partner: UNT Libraries Government Documents Department
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Porpoising: A Comparison of Theory With Experiment

Description: Report presenting a direct comparison between the observed and the calculated longitudinal dynamic stability of a particular dynamic model of a flying boat moving on the water. Good agreement was obtained between experiment and theory for trim angles in the vicinity of lower limit, at one speed a little above the hump.
Date: July 1943
Creator: Davidson, Kenneth S. M.; Locke, F. W. S., Jr. & Suarez, Anthony
Partner: UNT Libraries Government Documents Department
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Water tolerance of aviation gasoline containing xylidines

Description: Report presenting investigations to determine the effect of xylidines on the saturation concentration of water in aviation gasoline. The saturation concentration of water in gasoline containing 0, 1, and 3 percent xylidines was determined using fresh water at two temperatures and sea water at one temperature.
Date: July 1943
Creator: Revilock, Joseph & Olson, Walter T.
Partner: UNT Libraries Government Documents Department
open access

The effect of xylidines on the corrosiveness of aircraft-engine oil

Description: Report presenting testing to determine the effect of xylidines of the corrosiveness of aircraft-engine oil toward engine bearings as part of an investigation on the suitability of xylidines as an antiknock component in aviation gasoline. Results regarding the loss in bearing weight, corrosion losses, temperature characteristics, and types of corrosion are provided.
Date: July 1943
Creator: Meyrowitz, Emanuel & Olson, Walter T.
Partner: UNT Libraries Government Documents Department
open access

Working Charts for the Computation of Propeller Thrust Throughout the Take-Off Range

Description: Report presenting data from tests conducted on full-scale propellers with 3155 blade design, which have been used to construct a set of propeller thrust charts for use in the calculation of take-off performance. By using the charts, the thrust of modern single- and dual-rotating propellers may be easily and rapidly calculated through the entire take-off range.
Date: July 1943
Creator: Desmond, Gerald L. & Freitag, Robert F.
Partner: UNT Libraries Government Documents Department
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Theory of Self-Excited Mechanical Oscillations of Hinged Rotor Blades

Description: "Vibrations of rotary-wing aircraft may derive their energy from the rotation of the rotor rather than from the air forces. A theoretical analysis of these vibrations is described and methods for its application are explained herein" (p. 1). Information about self-excited speed range and shaft-critical speed are provided for any rotor with more than two blades.
Date: July 1943
Creator: Coleman, Robert P.
Partner: UNT Libraries Government Documents Department
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Effect of Turbulence on Air-Flow Measurements Behind Orifice Plates

Description: Report presenting determination of air-flow quantity in front of and behind three orifice plates to determine the errors introduced in the quantity measurements by the turbulence behind the orifice plates. For the orifice plates tested, the results showed that the measurements must be taken 40 to 60 hole diameters downstream from the plates to ensure accuracy.
Date: July 1943
Creator: Nielsen, Jack N.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Tests of the 1/9-Scale Model of the Curtiss XP-62 Airplane with Various Vertical Tail Arrangements

Description: The effect of various vertical tail arrangements upon the stability and control characteristics of an XP-62 fighter model was investigated. Rudder-free yaw characteristics with take-off power and flaps deflected were satisfactory after dorsal fin modifications. Directional stability was obtained with all modified vertical tails. Satisfactory rudder effectiveness resulted partly because the dual-rotation propellers produced no asymmetric yawing moments. Pedal forces in sideslips were undesirably… more
Date: July 1943
Creator: Recant, I. G. & Wallace, Arthur R.
Partner: UNT Libraries Government Documents Department
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Some Yawing Tests of a 1/30-Scale Model of the Hull of the XPB2M-1 Flying Boat

Description: Report discusses the results of yawing tests on a model of the complete hull of the XPB2M-1. The tests indicated that there was a tendency toward directional instability in the vicinity of the hump. The researchers concluded that at a certain range, the curves of yawing moment are discontinuous, and this has led to difficulty in preliminary test flights.
Date: July 1943
Creator: Locke, F. W. S., Jr.
Partner: UNT Libraries Government Documents Department
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Measurements of Friction Coefficients in a Pipe for Subsonic and Supersonic Flow of Air

Description: Report presenting tests of the flow of air through brass tubes with the friction coefficient and incompressible flow relation as the main focus. The analytical relation between friction coefficient, tube length, and Mach number is shown for flow without shock and the conditions for flow with and without shock are delimited.
Date: July 1943
Creator: Keenan, Joseph H. & Neumann, Ernest P.
Partner: UNT Libraries Government Documents Department
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On a function-theory method for obtaining potential-flow patterns of a compressible fluid

Description: Report presenting a method for obtaining exact potential-flow patterns in a compressible fluid. The method is based on a complex-function theory developed for the solutions of the simultaneous first-order partial differential equations in the hodograph variables.
Date: July 1943
Creator: Gelbart, Abe
Partner: UNT Libraries Government Documents Department
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Investigation for the Development of a High-Speed Antiaircraft Tow Target

Description: Report presenting an investigation for the purpose of developing a target which can be towed satisfactorily at high speeds. Testing included drag measurements and visual observations of the stability characteristics of several full-scale and scale models of sleeve-type tow targets. The drag coefficients obtained for the currently used targets were found to be excessively high.
Date: July 1943
Creator: Migotsky, Eugene
Partner: UNT Libraries Government Documents Department
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