Technical Report Archive & Image Library (TRAIL) - 190 Matching Results

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The Breda Wind Tunnel

Description: A description of the design and construction of the Breda wind tunnel. The tunnel is equipped with a two-meter throat diameter and a 310 kph velocity potential.
Date: December 1939
Creator: Pittoni, Mario
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Contribution to the Aerodynamics of Rotating-Wing Aircraft

Description: "The chief defect of the investigations up to now was the assumption of a more or less arbitrary "mean" drag coefficient for a section of the blade. This defect is remedied through replacement of the constant coefficient by a function of higher order which corresponds to the polar curve of the employed profile. In that way it is possible to extend the theory to include the entire range from "autogyro" without power input to the driven "helicopter" with forward-tilted rotor axis. The treatment i… more
Date: December 1939
Creator: Sissingh, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Effect of Streamlining the Afterbody of an N.A.C.A. Cowling

Description: "The drag and the power cost associated with the changing of the nose of a nacelle from a streamline shape to a conventional N.A.C.A. cowling shape was investigated in the N.A.C.A. 20-foot tunnel. Full-scale propellers and nacelles were used. The increment of drag associated with the change of nose shapes was found to be critically dependent on the afterbody of the nacelle" (p. 1).
Date: December 1939
Creator: Stickle, George W.; Crigler, John L. & Naiman, Irven
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Effect of Streamlining the Aterbody of an N.A.C.A. Cowling

Description: Report presenting an investigation of the drag and power cost associated with the changing of the nose of a nacelle from a streamline shape to a conventional cowling shape. Full-scale propellers and nacelles were used. The results of the tests showed that the streamline afterbody drag approached that of an airship form and that the added drag due to the open-nose cowling was only a quarter of the drag increase obtained with the other afterbody.
Date: December 1939
Creator: Stickle, George W.; Crigler, John L. & Naiman, Irven
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Local instability of columns with I-, Z-, channel, and rectangular-tube sections

Description: From Summary: "Charts are presented for the coefficients in the formulas for the critical compressive stress at which cross-sectional distortion begins in thin-wall columns of I-, Z-, channel, and rectangular-tube sections. The energy method of Timoshenko was used in the theoretical calculations required for the construction of the charts. The deflection equations were carefully selected to give good accuracy. The calculation of the critical compressive stress at stresses above the elastic rang… more
Date: December 1939
Creator: Stowell, Elbridge Z. & Lundquist, Eugene E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Modern Methods of Testing

Description: After a brief survey of the commonly used single-value test methods, the importance of the determination of the incipient knock for the octane number is discussed and improvements suggested for the knock testing in the CFR engine. The DVL supercharge test method with its superiority of direct determination of fuel knock in each single cylinder of an airplane engine without involving structural changes, is described and the advantages of a multiple-value method enumerated. A diagrammatic present… more
Date: December 1939
Creator: Seeber, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Observations in Flight of the Region of Stalled Flow Over the Blades of an Autogiro Rotor

Description: "The flow over the inner halves of the rotor blades on a Kellet YG-1B autogiro was investigated in flight by making camera records of the motion of silk streamers attached to the upper surfaces of the blades. These records were analyzed to determine the boundaries of the region within which the flow over the blade sections was stalled for various tip-speed ratios. For the sake of comparison, corresponding theoretical boundaries were obtained. Both the size of the stalled area and its rate of gr… more
Date: December 1939
Creator: Bailey, F. J., Jr. & Gustafson, F. B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Pressure-Distribution Measurements on a Rectangular Wing With a Partial-Span Split Flap in Curved Flight

Description: "Pressure-distribution tests were made on the 32-foot whirling arm of the Daniel Guggenheim Airship Institute of a rectangular wing of NACA 23012 section to determine the rolling and the yawing moment due to angular velocity in yaw. The model was tested at 0 and 5 degree pitch; 0, +/- 5, and +/- 10 degrees yaw; and with no flap and with split flaps 25, 50 and 75 percent of the wing span and deflected 60 degrees. The results are given in the form of span load distributions and as calculated mome… more
Date: December 1939
Creator: Rokus, Frank G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Profile-Drag Investigation of an Airplane Wing Equipped with Rubber Inflatable De-Icer

Description: "The National Advisory Committee for Aeronautics has made profile-drag measurements in flight of a wing which was equipped with a rubber inflatable de-icer and to which various stimulated ice formations were attached. Tuft observations at the stalling speed of the wing with the various drag conditions were made in order to determine the influence on the maximum lift coefficient. The de-icer installation caused an increase of from 10-20% in the profile drag of the plain wing and reduced CL(sub m… more
Date: December 1939
Creator: Rodert, Lewis A. & Jones, Alun R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Recurrence Formula for Shear-Lag Problems

Description: "The analysis of the bending action in box beams with appreciable shear deformation of the flanges becomes very difficult in the general case of variable cross section and loading. This paper presents a convenient method of solving the problem by the familiar method of dividing the beam into a number of bays that can be assumed to have constant cross section and loading. Application of formerly derived shear-lag formulas leads to a general equation closely analogous in form to the well-known th… more
Date: December 1939
Creator: Kuhn, Paul
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Stress concentration around an open circular hole in a plate subjected to bending normal to the plane of the plate

Description: "An aluminum-alloy plate containing an open circular hole of diameter large compared with the thickness of the plate was subjected to bending forces normal to the plane of the plate. Deflection and strain measurements were taken for two different loads. Stress concentrations occurred at the edge of the hole and the maximum stresses were tangential to the hole at the ends of the transverse diameter. The maximum stress at the edge of the hole was 1.59 times the computed stress on the net section … more
Date: December 1939
Creator: Dumont, C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of fuel-air ratio, inlet temperature, and exhaust pressure on detonation

Description: From Summary: "An accurate determination of the end-gas condition was attempted by applying a refined method of analysis to experimental results. The results are compared with those obtained in Technical Report no. 655. The experimental technique employed afforded excellent control over the engine variables and unusual cyclic reproducibility. This, in conjunction with the new analysis, made possible the determination of the state of the end-gas at any instant to a fair degree of precision. Resu… more
Date: November 15, 1939
Creator: Taylor, E. S.; Leary, W. A. & Diver, J. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Corrugated Metal Diaphragms for Aircraft Pressure-Measuring Instruments

Description: Note presenting a description of a large number of corrugated diaphragms of beryllium copper, phosphor bronze, and Z-nickel with geometrically similar outlines but various diameters and thicknesses were formed by hydraulic pressing. The apparatus and technique used in the manufacture, testing, and heat treatment are described. Results regarding pressure-deflection curves, load limit, effect of center reinforcing, snap-action diaphragms, deflection traverse, thickness variations, and concentrate… more
Date: November 1939
Creator: Wildhack, W. A. & Goerke, V. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Effect of Compressibility on the Pressure Reading of a Prandtl Pitot Tube at Subsonic Flow Velocity

Description: Errors arising from yawed flow were also determined up to 20 degrees angle of attack. In axial flow, the Prandtl pitot tube begins at w/a approx. = 0.8 to give an incorrect static pressure reading, while it records the tank pressure correctly, as anticipated, up to sonic velocity. Owing to the compressibility of the air, the Prandtl pitot tube manifests compression shocks when the air speed approaches velocity of sound. This affects the pressure reading of the instrument. Because of the increas… more
Date: November 1939
Creator: Walchner, O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The effect of the slipstream on an airplane wing

Description: The conditions which must be met at the slipstream boundary are developed, after which it is shown with the aid of the reflection method how these limiting conditions may be complied with in the case of an airfoil in a propeller slipstream in horizontal flow as well as for the propeller in yaw and with allowance for the slipstream rotation. In connection herewith, it is shown how the effective angles of attack and the circulation distribution with due regard to slipstream effect can be predicte… more
Date: November 1939
Creator: Franke, A. & Weinig, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Engine Operation in Flight for Minimum Fuel Consumption

Description: "Engine and airplane performance data have been gathered from various sources and analyzed to determine indications of the most economical methods of flight operation from a consideration of fuel expenditure. The analysis includes the influence of such facts as fuel-air ratio, engine speed, engine knock, altitude, cylinder cooling, spark timing, and limits of cruising brake mean effective pressure. The results indicate that the cheapest power is obtained with approximately correct mixture at lo… more
Date: November 1939
Creator: Reuter, George
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Enlarged N.A.C.A. Tank, and Some of Its Work

Description: The most conspicuous of the features of the enlarged N.A.C.A. tank are derived directly from those of the original tank and owe their present form not only to the reasons for their first use but also to the experience obtained with them. As in the original tank, there are: 1) A basin of great length (new 2,880 feet); 2) Rails made of structural H beams, without machining; 3) A towing carriage of very high speed (now 80 mph maximum); 4) Rubber tires on all the wheels, pneumatic on the running wh… more
Date: November 1939
Creator: Truscott, Starr
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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An Investigation of the Prevention of Ice on the Airplane Windshield

Description: "An investigation has been completed on several methods for the prevention and removal of ice on an airplane windshield. Tests were made on the use of electric heating, hot-air heating, and an alcohol-dispensing, rotating wiper blade. The results showed that vision through the airplane windshield could be maintained during severe icing conditions by the use of heat" (p. 1).
Date: November 1939
Creator: Rodert, Lewis A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Mechanical Properties of Flush-Riveted Joints

Description: "The strength of representative types of flush-riveted joints has been determined by testing 865 single-shearing, double-shearing, and tensile specimens representing 7 types of rivet and 18 types of joint. The results, presented in graphic form, show the stress at failure, type of failure, and d/t ratio. In general, dimpled joints were appreciably stronger than countersunk or protruding-head joints, but their strength was greatly influenced by constructional details" (p. 467).
Date: November 1939
Creator: Brueggeman, W. C. & Roop, Frederick C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Photoelastic Analysis of Three-Dimensional Stress Systems Using Scattered Light

Description: "A method has been developed for making photoelastic analyses of three-dimensional stress systems by utilizing the polarization phenomena associated with the scattering of light. By this method, the maximum shear and the directions of the three principal stresses at any point within a model can be determined, and the two principal stresses at a free-bounding surface can be separately evaluated. Polarized light is projected into the model through a slit so that it illuminates a plane section" (p… more
Date: November 1939
Creator: Weller, R. & Bussey, J. K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Pressure-Distribution Investigation of an N.A.C.A. 0009 Airfoil With a 50-Percent-Chord Plain Flap and Three Tabs

Description: "Pressure-distribution tests of an N.A.C.A. 0009 airfoil with a 50-percent-chord plain flap and three plain tabs, having chords 10, 20, and 30 percent of the flap chord, were made in the N.A.C.A. 4- by 6- foot vertical tunnel. The tests supplied aerodynamic section data that may be applied to the design of horizontal and vertical tail surfaces. The results are presented as resultant-pressure diagrams for the airfoil with the flap and the 20-percent-chord tab" (p. 1).
Date: November 1939
Creator: Street, William G. & Ames, Milton B., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Pressure-Distribution Measurements on a Tapered Wing With a Partial-Span Split Flap in Curved Flight

Description: "Pressure-distribution tests were made on the 32-foot whirling arm of the Daniel Guggenheim Airship Institute of a tapered wing to determine the rolling and the yawing moments due to an angular velocity in yaw. The model was tested at 0 degree and 5 degree pitch; 0 degree, 5 degree, and 10 degree yaw; and with split flaps covering 25, 50, 75, and 100 percent of the wing span and deflected 60 degrees. The results are given in the form of load distributions and as calculated moment coefficients" … more
Date: November 1939
Creator: Troller, T. & Rokus, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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