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Aerodynamic characteristics of NACA 23012 and 23021 airfoils with 20-percent-chord external-airfoil flaps of NACA 23012 section

Description: Report presents the results of an investigation of the general aerodynamic characteristics of the NACA 23012 and 23021 airfoils, each equipped with a 0.20c external flap of NACA 23012 section. The tests were made in the NACA 7 by 10-foot and variable-density wind tunnels and covered a range of Reynolds numbers that included values corresponding to those for landing conditions of a wide range of airplanes. Besides a determination of the variation of lift and drag characteristics with position of the flap relative to the main airfoil, complete aerodynamic characteristics of the airfoil-flap combination with a flap hinge axis selected to give small hinge moments were measured in the two tunnels. Some measurements of air loads on the flap itself in the presence of the wing were made in the 7 by 10-foot wind tunnel.
Date: 1937~
Creator: Platt, Robert C & Abbott, Ira H

The aerodynamic characteristics of six full-scale propellers having different airfoil sections

Description: From Summary: "Wind-tunnel tests are reported of six 3-blade 10-foot propellers operated in front of a liquid-cooled engine nacelle. The propellers were identical except for blade airfoil sections, which were: Clark y, R.A.F. 6, NACA 4400, NACA 2400-34, NACA 2rsub200, and NACA 6400. The range of blade angles investigated extended for 15 degrees to 40 degrees for all propellers except the Clark y, for which it extended to 45 degrees. The results showed that the range in maximum efficiency between the highest and lowest values was about 3 percent. The highest efficiencies were for the low-camber sections."
Date: 1939
Creator: Biermann, David & Hartman, Edwin P

Aerodynamic characteristics of twenty-four airfoils at high speeds

Description: From Summary: "If a propeller is mounted directly on the of a modern high-speed airplane engine, the outer airfoil sections of the propeller travel at speeds approaching the speed of sound. It is possible by the use of gearing and a somewhat larger propeller to reduce the speed of the propeller sections, but only at the expense of additional weight and some frictional loss of power. This report presents the results of this work."
Date: 1930~
Creator: Brigg, L. J. & Dryden, H. L.

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

The aerodynamic effects of wing cut-outs

Description: From Introduction: "The information now available concerning wing cut-outs or applicable to the analysis of their effects is plentiful (references 1 to 7) but too disconnected and unorganized to be of the greatest possible usefulness. In connection with the interference program being conducted in the N.A.C.A. varible-density wind tunnel, an analysis was therefore made of existing material to determine the qualitative effects of the different features of wing cut-outs, and to obtain means of calculating wing characteristics as affected by them."
Date: 1934
Creator: Sherman, Albert

The aerodynamic forces and moments exerted on a spinning model of the NY-1 airplane as measured by the spinning balance

Description: From Summary: "A preliminary investigation of the effects of changes in the elevator and rudder settings and of small changes in attitude upon the aerodynamic forces and moments exerted upon a spinning airplane was undertaken with the spinning balance in the 5-foot vertical tunnel of the National Advisory Committee for Aeronautics. The tests were made on a 1/12-scale model of the "NY-1" airplane. Data by which to fix the attitude, the radius of spin, and the rotational and air velocities were taken from recorded spins of the full-scale airplane."
Date: February 7, 1933
Creator: Bamber, M J & Zimmerm, N, C h

Air conditions close to the ground and the effect on airplane landings

Description: This report presents the results of an investigation undertaken to determine the feasibility of making glide landings in gusty air. Wind velocities were measured at several stations between the ground and a height of 51 feet, and flight tests were made to determine the actual influence of gusts on an airplane gliding close to the ground.
Date: April 3, 1934
Creator: Thompson, F L; Peck, W C & Beard, A P

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

Air flow in a separating laminar boundary layer

Description: Report discussing the speed distribution in a laminar boundary layer on the surface of an elliptic cylinder, of major and minor axes 11.78 and 3.98 inches, respectively, has been determined by means of a hot-wire anemometer. The direction of the impinging air stream was parallel to the major axis. Special attention was given to the region of separation and to the exact location of the point of separation. An approximate method, developed by K. Pohlhausen for computing the speed distribution, the thickness of the layer, and the point of separation, is described in detail; and speed-distribution curves calculated by this method are presented for comparison with experiment.
Date: December 1, 1934
Creator: Schubauer, G. B.

Air flow in the boundary layer near a plate

Description: From Summary: "The published data on the distribution of speed near a thin flat plate with sharp leading edge placed parallel to the flow (skin friction plate) are reviewed and the results of some additional measurements are described. The purpose of the experiments was to study the basic phenomena of boundary-layer flow under simple conditions."
Date: March 1936
Creator: Dryden, Hugh L.

Air flow in the boundary layer of an elliptic cylinder

Description: From Introduction: "The present investigation was carried out for the purpose of supplementing the earlier work with information on the boundary layer under such conditions of air speed and turbulence that transition occurs and the layer is partly laminar and partly turbulent. In the work reported in reference 1, the air speed was about 12 feet per second, and it was assumed that the boundary layer remained in the laminar condition until after separation because the separation point remained fixed and the pressure distribution about the cylinder was unaffected until an air speed of 15 feet per second was reached."
Date: August 6, 1938
Creator: Schubauer, G B

Air propellers in yaw

Description: Report presents the results of tests conducted at Stanford University of a 3-foot model propeller at four pitch settings and at 0 degree, 10 degrees, 20 degrees, and 30 degrees yaw.
Date: January 1, 1937
Creator: Lesley, E P; Worley, George F & Moy, Stanley

Aircraft accidents : method of analysis

Description: The revised report includes the chart for the analysis of aircraft accidents, combining consideration of the immediate causes, underlying causes, and results of accidents, as prepared by the special committee, with a number of the definitions clarified. A brief statement of the organization and work of the special committee and of the Committee on Aircraft Accidents; and statistical tables giving a comparison of the types of accidents and causes of accidents in the military services on the one hand and in civil aviation on the other, together with explanations of some of the important differences noted in these tables.
Date: January 1, 1931

Aircraft compass characteristics

Description: From Summary: "A description of the test methods used at the National Bureau of Standards for determining the characteristics of aircraft compasses is given. The methods described are particularly applicable to compasses in which mineral oil is used as the damping liquid. Data on the viscosity and density of certain mineral oils used in United States Navy aircraft compasses are presented. Results of flight tests are presented."
Date: January 1, 1937
Creator: Peterson, John B. & Smith, Clyde W.

Aircraft power-plant instruments

Description: From Summary: "The report includes a description of the commonly used types and some others, the underlying principle utilized in the design, and some design data. The inherent errors of the instrument, the methods of making laboratory tests, descriptions of the test apparatus, and data in considerable detail in the performance of commonly used instruments are presented. Standard instruments and, in cases where it appears to be of interest, those used as secondary standards are described."
Date: January 1, 1934
Creator: Sontag, Harcourt & Brombacher, W. G.

Aircraft rate-of-climb indicators

Description: From Summary: "The theory of the rate-of-climb indicator is developed in a form adapted for application to the instrument in its present-day form. Certain dynamic effects, including instrument lag, and the use of the rate-of-climb indicator as a statoscope are also considered. Modern instruments are described. A laboratory test procedure is outlined and test results are given."
Date: January 1, 1939
Creator: Johnson, Daniel P.

Aircraft speed instruments

Description: From Summary: "This report presents a concise survey of the measurement of air speed and ground speed on board aircraft. Special attention is paid to the Pitot-static air-speed meter which is the standard in the United States for airplanes. A bibliography on air-speed measurement concludes the report."
Date: January 1, 1933
Creator: Beij, K Hilding

Aircraft woods: their properties, selection, and characteristics

Description: From Summary: "This report presents, further, information on the properties of various other native species of wood compared with spruce, and discusses the characteristics of a considerable number of them from the standpoint of their possible application in aircraft manufacture to supplement the woods that are now most commonly used."
Date: January 1, 1931
Creator: Markwardt, L J

Airfoil pressure distribution investigation in the variable density wind tunnel

Description: Report presents the results of wind tunnel tests of pressure distribution measurements over one section each of six airfoils. Pressure distribution diagrams, as well as the integrated characteristics of the airfoils, are given for both a high and a low dynamic scale or, Reynolds number VL/V, for comparison with flight and other wind-tunnel tests, respectively. It is concluded that the scale effect is very important only at angles of attack near the burble.
Date: January 1, 1931
Creator: Jacobs, Eastman N.; Stack, John & Pinkerton, Robert M

Airfoil section characteristics as affected by variations of the Reynolds number

Description: Report presents the results of an investigation of a systematically chosen representative group of related airfoils conducted in the NACA variable-density wind tunnel over a wide range of Reynolds number extending well into the flight range. The tests were made to provide information from which the variations of airfoil section characteristics with changes in the Reynolds number could be inferred and methods of allowing for these variations in practice could be determined. This work is one phase of an extensive and general airfoil investigation being conducted in the variable-density tunnel and extends the previously published researches concerning airfoil characteristics as affected by variations in airfoil profile determined at a single value of the Reynolds number.
Date: 1939
Creator: Jacobs, Eastman N. & Sherman, Albert

Airfoil section characteristics as applied to the prediction of air forces and their distribution on wings

Description: From Introduction: "The system presented herein yields, within the limitations of our present knowledge of aerodynamics, a general solution of the resultant wing forces and moments and their distribution. For the sake of completeness and facility in use, the report contains a table of the important section parameters for many commonly used sections and all other necessary data required to solve the most practical design problems coming within the scope of the system."
Date: 1938
Creator: Jacobs, Eastman N. & Rhode, R. V.