Technical Report Archive and Image Library (TRAIL) - 118 Matching Results

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The 6-foot-4-inch wind tunnel at the Washington Navy Yard

Description: Report discussing the 6-foot-4-inch wind tunnel and its auxiliary equipment has proven itself capable of continuous and reliable output of data. The real value of the tunnel will increase as experience is gained in checking the observed tunnel performance against full-scale performance. Such has been the case of the 8- by 8-foot tunnel, and for that reason the comparison in the calibration tests have been presented.
Date: August 1935
Creator: Desmond, G L & Mccrary, J A
Partner: UNT Libraries Government Documents Department

The aerodynamic aspect of wing-fuselage fillets

Description: Report discussing model tests prove the feasibility of enhancing the aerodynamic qualities of wing-fuselage fillets by appropriate design of fuselage and wing roots. Abrupt changes from maximum fuselage height to wing chord must be avoided and every longitudinal section of fuselage and wing roots must be so faired and arranged as to preserve the original lift distribution of the continuous wing. Adapting the fuselage to the curvilinear circulation of the wing affords further improvement. The polars of such arrangements are almost the same as those of the "wing alone," thus voiding the superiority of the high-wing type airplane known with conventional design.
Date: February 1935
Creator: Muttray, H
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of a wing with Fowler flaps including flap loads, downwash, and calculated effect on take-off

Description: From Summary: "This report presents the results of wind tunnel tests of a wing in combination with each of three sizes of Fowler flap. The purpose of the investigation was to determine the aerodynamic characteristics as affected by flap chord and position, the air loads on the flaps, and the effect of flaps on the downwash."
Date: 1935
Creator: Platt, Robert C
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of several airfoils of low aspect ratio

Description: From Summary: "This paper presents the results of wind-tunnel tests of several airfoils of low aspect ratio. The airfoils included three circular Clark Y airfoils with different amounts of dihedral, two Clark Y airfoils with slots in their portions, and three flat-plate airfoils. Lift, drag, and pitching-moment characteristics of the slotted airfoils with slots open and closed; pitching moment characteristics of one of the slotted airfoils with slots open and closed; and lift characteristics of the flat-plate airfoils are included. The results reveal a definite improvement of lift, drag, and pitching-moment characteristics with increase in dihedral of the circular Clark Y wing. Lift characteristics near the stall were found to depend markedly on the shape of the extreme tip but were not greatly affected by slots through the after portion of the airfoils. Changes in plan form of the flat-plate airfoils gave erroneous indications of the effect to be expected from changes in plan form of an airfoil of Clark Y section. The minimum drag characteristics of the circular Clark Y airfoils were found to be substantially the same as for a Clark Y airfoil of conventional aspect ratio."
Date: August 1935
Creator: Zimmerman, C H
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of wings with cambered external airfoil flaps, including lateral control, with a full-span flap

Description: From Summary: "The results of a wind-tunnel investigation of the NACA 23012, the NACA 23021, and the Clark Y airfoils, each equipped with a cambered external-airfoil flap, are presented in this report. The purpose of the research was to determine the relative merit of the various airfoils in combination with the cambered flap and to investigate the use of the flap as a combined lateral-control and high-lift device."
Date: 1935
Creator: Platt, Robert C
Partner: UNT Libraries Government Documents Department

The aerodynamic drag of flying-boat hull model as measured in the NACA 20-foot wind tunnel I.

Description: From Introduction: "The main purpose of this investigation is to make available to the designer useful information with regard to the aerodynamic drag of various types of flying-boat hull models. The present report is the first in a series covering investigation in this field. Through close cooperation between hydrodynamics and aerodynamics divisions it is hoped that results leading to improvements in hull design obtained."
Date: April 1935
Creator: Hartman, Edwin P
Partner: UNT Libraries Government Documents Department

The aerodynamic forces and moments on a spinning model of the F4B-2 airplane as measured by the spinning balance

Description: From Introduction: "The tests described in this report were made as part of an investigation of the spinning characteristics of the F4B-2 airplane conducted at the request of the Bureau of Aeronautics, Navy Department."
Date: February 1935
Creator: Bamber, M J & Zimmerman, C H
Partner: UNT Libraries Government Documents Department

Air flow around finned cylinders

Description: Report presents the results of a study made to determine the air-flow characteristics around finned cylinders. Air-flow distribution is given for a smooth cylinder, for a finned cylinder having several fin spacings and fin widths, and for a cylinder with several types of baffle with various entrance and exit shapes. The results of these tests show: that flow characteristics around a cylinder are not so critical to changes in fin width as they are to fin spacing; that the entrance of the baffle has a marked influence on its efficiency; that properly designed baffles increase the air flow over the rear of the cylinder; and that these tests check those of heat-transfer tests in the choice of the best baffle.
Date: November 7, 1935
Creator: Brevoort, M J & Rollin, Vern G
Partner: UNT Libraries Government Documents Department

Alaska-Yukon Caribou

Description: Brief summary of the physical characteristics, general habits, breeding habits, food habits, migratory habits, and habitat of the Alaska-Yukon caribou.
Date: June 1935
Creator: Murie, Olaus J.
Partner: UNT Libraries Government Documents Department

An application of the von Karman-Millikan laminar boundary-layer theory and comparison with experiment

Description: The von Karman-Millikan theory of laminar boundary layers presented in NACA Technical Report No. 504 is applied to the laminar boundary layer about an elliptic cylinder on which boundary-layer and pressure-distribution measurements were made. An outline of the procedure of the von Karman-Millikan method is given. Good agreement is obtained between the calculated and experimental results, indicating that the method may be applied generally to the laminar boundary layer about any body provided that an experimentally determined pressure distribution is available. It appears that for all Reynolds Number above 24,000 the separation point for the elliptic cylinder should occur at a constant distance behind the point of minimum pressure, provided that the boundary layer does not become turbulent.
Date: October 1935
Creator: Von Doenhoff, Albert E
Partner: UNT Libraries Government Documents Department

Bending stresses due to torsion in cantilever box beams

Description: The paper beings with a brief discussion on the origin of the bending stresses in cantilever box beams under torsion. A critical survey of existing theory is followed by a summary of design formulas; this summary is based on the most complete solution published but omits all refinements considered unnecessary at the present state of development. Strain-gage tests made by NACA to obtained some experimental verification of the formulas are described next. Finally, the formulas are applied to a series of box beams previously static-tested by the U.S. Army Air Corps; the results show that the bending stresses due to torsion are responsible to a large extent for the free-edge type of failure frequently experienced in these tests.
Date: June 1, 1935
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department

Bureau of Mines Multiple-Diaphragm Recording Subsurface-Pressure Gage

Description: Report issued by the U.S. Bureau of Mines on the measuring of temperature and pressure in oil and gas wells. Descriptions of the instrumentation developed and used for these measurements are presented. This report includes tables, graphs, and illustrations.
Date: November 1935
Creator: Berwald, W. B.; Buss, H. A. & Reistle, C. E., Jr.
Partner: UNT Libraries Government Documents Department

Calculations of the effect of wing twist on the air forces acting on a monoplane wing

Description: A method is presented for calculating the aerodynamic forces on a moncylane wing, taking into account the elastic twisting of the wing due to these forces. The lift distribution along the span is calculated by the formulas of Amstutz as a function of the geometrical characteristics of the wing and of the twist at stations 60 and 90 percent of the semispan. The twist for a given lift distribution is calculated by means of influence lines. As a numerical example, the forces on a Swiss military D.2V airplane are calculated. Comparisons with the strip method and with the ordinary stress-analysis method are also given.
Date: January 1, 1935
Creator: Datwyler, G
Partner: UNT Libraries Government Documents Department

Coal-Mine Accidents in the United States, 1933

Description: Report compiled by the U.S. Bureau of Mines including statistics on fatal and non-fatal accidents in coal mines located in the United States as well as data regarding the various operations (e.g., number of miners employed and average production). The information is organized into tables for comparison and the text draws some overall conclusions in the summary.
Date: 1935
Creator: Adams, W. W. & Geyer, L. E.
Partner: UNT Libraries Government Documents Department

Combustion in a bomb with a fuel-injection system

Description: Fuel injected into a spherical bomb filled with air at a desired density and temperature could be ignited with a spark a few thousandths of a second after injection, an interval comparable with the ignition lag in fuel-injection engines. The effect of several variables on the extent and rate of combustion was investigated: time intervals between injection and ignition of fuel of 0.003 to 0.06 second and one of 5 minutes; initial air temperatures of 100 degrees C. to 250 degrees C.; initial air densities equivalent to 5, 10, and 15 absolute atmospheres pressure at 100 degrees C.; and air-fuel ratios of 5 to 25.
Date: January 1, 1935
Creator: Cohn, Mildred & Spencer, Robert C
Partner: UNT Libraries Government Documents Department

Comparative tests of Pitot-static tubes

Description: Comparative tests were made on seven conventional Pitot-static tubes to determine their static, dynamic, and resultant errors. The effect of varying the dynamic opening, static opening, wall thickness, and inner-tube diameter was investigated. Pressure-distribution measurements showing stem and tip effects were also made. A tentative design for a standard Pitot-static tube for use in measuring air velocity is submitted.
Date: November 1, 1935
Creator: Merriam, Kenneth G & Spaulding, Ellis R
Partner: UNT Libraries Government Documents Department

The compressibility bubble

Description: Simultaneous air-flow photographs and pressure-distribution measurements have been made of the NACA 4412 airfoil at high speeds in order to determine the physical nature of the compressibility bubble. The flow photographs were obtained by the Schlieren method and the pressures were simultaneously measured for 54 stations on the 5-inch-chord wing by means of a multiple-tube photographic manometer. Pressure-measurement results and typical Schlieren photographs are presented. The general nature of the phenomenon called the "compressibility bubble" is shown by these experiments. The source of the increased drag is the compression shock that occurs, the excess drag being due to the conversion of a considerable amount of the air-stream kinetic energy into heat at the compression shock.
Date: October 1, 1935
Creator: Stack, John
Partner: UNT Libraries Government Documents Department