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  Partner: UNT Libraries Government Documents Department
 Decade: 1930-1939
 Collection: National Advisory Committee for Aeronautics Collection
The aerodynamic drag of five models of side floats N.A.C.A. Models 51-E, 51-F, 51-G, 51-H, 51-J

The aerodynamic drag of five models of side floats N.A.C.A. Models 51-E, 51-F, 51-G, 51-H, 51-J

Date: December 1, 1938
Creator: House, R O
Description: The drag of five models of side floats was measured in the N.A.C.A. 7- by 10-foot wind tunnel. The most promising method of reducing the drag of floats indicated by these tests is lowering the angle at which the floats are rigged. The addition of a step to a float does not always increase the drag in the flying range, floats with steps sometimes having lower drag than similar floats without steps. Making the bow chine no higher than necessary might result in a reduction in air drag because of the lower angle of pitch of the chines. Since side floats are used formally to obtain lateral stability when the seaplane is operating on the water at slow speeds or at rest, greater consideration can be given to factors affecting aerodynamic drag than is possible for other types of floats and hulls.
Contributing Partner: UNT Libraries Government Documents Department
The aerodynamic drag of flying-boat hull model as measured in the NACA 20-foot wind tunnel I.

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

Date: April 1, 1935
Creator: Hartman, Edwin P
Description: Measurements of aerodynamic drag were made in the 20-foot wind tunnel on a representative group of 11 flying-boat hull models. Four of the models were modified to investigate the effect of variations in over-all height, contours of deck, depth of step, angle of afterbody keel, and the addition of spray strips and windshields. The results of these tests, which cover a pitch-angle range from -5 to 10 degrees, are presented in a form suitable for use in performance calculations and for design purposes.
Contributing Partner: UNT Libraries Government Documents Department
The aerodynamic effect of a retractable landing gear

The aerodynamic effect of a retractable landing gear

Date: March 1, 1933
Creator: Defrance, Smith J
Description: Tests were conducted in the N.A.C.A. full scale wind tunnel at the request of the Army Air Corps to determine the effect of retractable landing gear openings in the bottom surface of a wing upon the characteristics of a Lockheed Altair airplane. The tests were extended to include the determination of the lift and drag characteristics throughout the angle-of-attack range with the landing gear both retracted and extended. Covering the wheel openings in the wing with sheet metal when the wheels were extended reduced the drag only 2 percent at a lift coefficient of 1.0, which was assumed for the take-off condition. Therefore, the wheel openings in the bottom side of the wing have a negligible effect upon the take-off of the airplane. Retracting the landing gear reduced the minimum drag of the complete airplane 50 percent.
Contributing Partner: UNT Libraries Government Documents Department
Aerodynamic effects of a split flap on the spinning characteristics of a monoplane model

Aerodynamic effects of a split flap on the spinning characteristics of a monoplane model

Date: December 1, 1934
Creator: Bamber, M J
Description: The investigation described in this report was made to determine the change in aerodynamic forces and moments produced by split flaps in a steady spin. The test were made with the spinning balance in the NACA 5-foot vertical wind tunnel. A low-wing monoplane model was tested with and without the split flaps in 12 spinning attitudes chosen to cover the probable spinning range. The changes in coefficients produced by adding the split flaps are given for longitudinal force, normal force, and rolling and yawing moments about body axes. The results obtained indicate that the use of split flaps on an airplane is unlikely, in any case, to have much beneficial effect on a spin, and it might make the spin dangerous. The change in the spin will depend upon the aerodynamic and inertia characteristics of the particular airplane. A dangerous condition is most likely to be attained with airplanes which are statically stable in yaw in the spinning attitude and which have large weights distributed along wings.
Contributing Partner: UNT Libraries Government Documents Department
The aerodynamic effects of wing cut-outs

The aerodynamic effects of wing cut-outs

Date: January 1, 1935
Creator: Sherman, Albert
Description: In connection with the interference program being conducted in the NACA variable-density wind tunnel, an analysis was made of available material with the object of presenting a qualitative discussion on wing characteristics as affected by cut-outs and of determining means for their quantitative calculation.
Contributing Partner: UNT Libraries Government Documents Department
The aerodynamic forces and moments exerted on a spinning model of the NY-1 airplane as measured by the spinning balance

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

Date: January 1, 1934
Creator: Bamber, M J & Zimmerm, N, C h
Description: 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. Two spinning conditions were investigated. All six components of the aerodynamic reaction were measured and are presented in coefficient form refereed to airplane axes. The results indicate that the change in yawing moment produced by the rudder with the elevator up was the only component of force or moment produced by the elevator and rudder that could not have been balanced in an actual spin by small changes in attitude and angular velocity.
Contributing Partner: UNT Libraries Government Documents Department
Aerodynamic forces and moments of a seaplane on the water

Aerodynamic forces and moments of a seaplane on the water

Date: November 1, 1933
Creator: Kohler, M
Description: This report gives the results of wind-tunnel tests with a seaplane model as a contribution to the solution of the aerodynamic problems. In the tests it was assumed that the seaplane rested motionless on the water and was exposed, in various positions with respect to the supposedly flat surface of the water, to a uniform air current 0 to 360 degrees.
Contributing 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

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

Date: February 1, 1935
Creator: Bamber, M J & Zimmerman, C H
Description: The aerodynamic forces and moments on a 1/12-scale model of the F4B-2 airplane were measured with the spinning balance in nine spinning attitudes with three sets of tail surfaces, namely, F4B-2 surfaces; F4B-4 fin and rudder with rectangular stabilizer; and with all tail surfaces removed. In one of these attitudes measurements were made to determine the effect upon the forces and moments of independent and of simultaneous displacement of the rudder and elevator for two of the sets of tail surfaces. Additional measurements were made for a comparison of model and full-scale data for six attitudes that were determined from flight tests with various control settings. The characteristics were found to vary in the usual manner with angle of attack and sideslip. The F4B-2 surfaces were quite ineffective as a source of yawing moments. The F4B-4 fin and F4B-2 stabilizer gave a greater damping yawing moment when controls were against the spin than did the F4B-2 surfaces but otherwise there was little difference. Substitution of a rectangular stabilizer for the F4B-2 stabilizer made no appreciable difference in the coefficient. Further comparisons with other airplane types are necessary before final conclusions can be drawn as to the relations between model and ...
Contributing Partner: UNT Libraries Government Documents Department
Aerodynamic Investigation of a Cup Anemometer

Aerodynamic Investigation of a Cup Anemometer

Date: July 1934
Creator: Hubbard, John D.
Description: Results of an investigation wherein the change of the normal force coefficient with Reynolds Number was obtained statically for a 15.5-centimeter hemispherical cup.
Contributing Partner: UNT Libraries Government Documents Department
Aerodynamic principles of the direct lifting propeller

Aerodynamic principles of the direct lifting propeller

Date: January 1, 1934
Creator: Schrenk, Martin
Description: The purpose of this report is to make the complicated processes on the direct-lift propeller amenable to analysis and observation. This is accomplished by placing the physical phenomena, starting with the most elementary process, in the foreground, while limiting the mathematical treatment to the most essential in view of the fundamental defects of the theorems. Comparison with model experiments supplements and corroborates the theoretical results.
Contributing Partner: UNT Libraries Government Documents Department