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Aerodynamic Investigation of a Cup Anemometer

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.
Date: July 1934
Creator: Hubbard, John D. & Brescoll, George P.
Partner: UNT Libraries Government Documents Department
open access

A complete tank test of a flying-boat hull with a pointed step - N.A.C.A. Model No. 22

Description: "The results of a complete tank test of a model of a flying-boat hull of unconventional form, having a deep pointed step, are presented in this note. The advantage of the pointed-step type over the usual forms of flying-boat hulls with respect to resistance at high speeds is pointed out. A take-off example using the data from these tests is worked out, and the results are compared with those of an example in which the test data for a hull of the type in general use in the United States are appl… more
Date: February 1934
Creator: Shoemaker, James M.
Partner: UNT Libraries Government Documents Department
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Effect of Retractable-Spoiler Location on Rolling- and Yawing-Moment Coefficients

Description: "In this report are presented the results of wind-tunnel tests of retractable spoilers on the upper surface of a Clark Y wing, which have been made as part of an investigation of lateral control devices being conducted by the National Advisory Committee for Aeronautics. Spoilers with chords up to 15.0 percent of the wing chord were tested in several locations on a plain rectangular wing and in two locations on the same wing equipped with a 20.0 percent chord split flap down 60 degrees. Charts a… more
Date: July 1934
Creator: Shortal, J. A.
Partner: UNT Libraries Government Documents Department
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Full-scale drag tests of landing lamps

Description: "Drag tests were conducted in the N.A.C.A. full-scale wind tunnel on full-scale models of two Army Air Corps type A-6 landing lamps mounted on an 8 by 48 foot airfoil. Drag measurements were made with the lamps in the leading edge and attached to the lower surface at the 5 and 10 percent chord positions. The drag of the lamps when faired into the airfoil was also measured. The results show that at 100 miles per hour and at the angle of minimum drag of the airfoil the unaired lamps in the leadin… more
Date: May 1934
Creator: Dearborn, C. H.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Measurements of Air Loads on Split Flaps

Description: Note presenting tests in a wind tunnel to determine the control forces and air loads acting on split flaps. Clark Y wing models were used with two different sizes of full-span split flaps, one with a medium chord and one with a narrow chord. The results indicated that at angles of attack and flap deflections for maximum lift, the lift loads on the split flaps were only 5 percent and 9 percent of the total lift for the narrow and medium-chord flaps respectively.
Date: May 1934
Creator: Wenzinger, Carl J.
Partner: UNT Libraries Government Documents Department
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The effect of trim angle on the take-off performance of a flying boat

Description: From Summary: "Data obtained at the N.A.C.A. tank from tests on the models of three flying-boat hulls - N.A.C.A. models 11-A, 16, and 22 - are used to demonstrate the effect of trim angle on water resistance. A specific example is taken, and data from Model 11-A are used to show that the trim angle giving the minimum water resistance will give minimum total air-plus-water resistance. Total-resistance curves for best trimmed angles and other angles are compared for the same example."
Date: January 1934
Creator: Shoemaker, James M. & Dawson, John R.
Partner: UNT Libraries Government Documents Department
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Tests of three tapered airfoils based on the N.A.C.A. 2200, the N.A.C.A.-M6, and the Clark Y sections

Description: Three tapered airfoils based on the N.A.C.A. 2200, the N.A.C.A.-M6, and the Clark Y sections were tested in the variable-density wind tunnel at a Reynolds Number of approximately 3,100,000. The models, which were of aspect ratio 6, had constant core center sections and rounded tips, and tapered in thickness from 18 percent at the roots to 9 percent at the tips. The aerodynamic characteristics are given by the usual dimensionless coefficients plotted for both positive and negative angles of atta… more
Date: January 1934
Creator: Anderson, Raymond F.
Partner: UNT Libraries Government Documents Department
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Landing characteristics of an autogiro

Description: An investigation to determine the rate of descent, the horizontal velocity, and the attitude at contact of an autogiro in landings was made by the National Advisory Committee for Aeronautics at the request of the Bureau of Air Commerce, Department of Commerce. The investigation covered various types of landings. The results of the investigation disclosed that the maximum rate of descent at contact with the ground (10.6 feet per second) was less than the minimum rate of descent attainable in a s… more
Date: November 1934
Creator: Peck, William C.
Partner: UNT Libraries Government Documents Department
open access

Tank Tests of Flat and V-Bottom Planning Surfaces

Description: "Four planing surfaces, all having beams of 16 inches and lengths of 60 inches but varying in dead rise by 10 degrees increments from 0 degrees to 30 degrees, were tested in the N.A.C.A. tank. The results cover a wide range of speed, loads, and trim angles, and are applicable to a variety of problems encountered in the design of seaplanes. The data are analyzed to determine the characteristics of each surface at the trim angle giving minimum resistance for all the speed and loads tested. A plan… more
Date: November 1934
Creator: Shoemaker, James M.
Partner: UNT Libraries Government Documents Department
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The Calculated Effect of Trailing-Edge Flaps on the Take-Off of Flying Boats

Description: "The results of take-off calculations are given for an application of simple trailing-edge flaps to two hypothetical flying boats, one having medium wing and power loading and consequently considerable excess of thrust over total resistance during the take-off run, the other having high wing and power loading and a very low excess thrust. For these seaplanes the effect of downward flap settings was: (1) to increase the total resistance below the stalling speed, (2) to decrease the get-away spee… more
Date: November 1934
Creator: Parkinson, J. B. & Bell, J. W.
Partner: UNT Libraries Government Documents Department
open access

A study of the pitching moments and the stability characteristics of monoplanes

Description: "This note presents a study of the pitching moments and the stability characteristics of monoplanes. Expressions for the pitching-moment coefficient and the Diehl stability coefficient for the monoplane are developed, suitable for the use of airplane designers. The effective difference between the high-wing and low-wing types is portrayed and discussed. Comparisons between experimental and computed values are made. Charts for use in the solution of numerical values of the pitching-moment and st… more
Date: November 1934
Creator: Higgins, George J.
Partner: UNT Libraries Government Documents Department
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Hazards to Aircraft Due to Electrical Phenomena

Description: Note presenting the findings of a committee established to consider the general question of hazards to aircraft due to electrical phenomena and make recommendations as to what should be done to insure the least hazard. The two primary hazards focused on were electrostatic attraction to the earth and high-frequency discharges.
Date: March 1934
Creator: Special Committee on Hazards to Aircraft Due to Electrical Pheomena
Partner: UNT Libraries Government Documents Department
open access

Effect of the Surface Condition of a Wing on the Aerodynamic Characteristics of an Airplane

Description: "In order to determine the effect of the surface conditions of a wing on the aerodynamic characteristics of an airplane, tests were conducted in the N.A.C.A. full-scale wind tunnel on the Fairchild F-22 airplane first with normal commercial finish of wing surface and later with the same wing polished. Comparison of the characteristics of the airplane with the two surface conditions shows that the polish caused a negligible change in the lift curve, but reduced the minimum drag coefficient by 0.… more
Date: April 1934
Creator: DeFrance, S. J.
Partner: UNT Libraries Government Documents Department
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A Preliminary Motion-Picture Study of Combustion in a Compression-Ignition Engine

Description: "Motion pictures were taken at 1,850 frames per second of the spray penetration and combustion occurring in the N.A.C.A. combustion apparatus arranged to operate as a compression-ignition engine. Indicator cards were taken simultaneously with the motion pictures by means of the N.A.C.A. optical indicator. The motion pictures showed that when ignition occurred during injection it started in the spray envelope. If ignition occurred after injection cut-off, however, and after considerable mixing h… more
Date: April 1934
Creator: Buckley, E. C. & Waldron, C. D.
Partner: UNT Libraries Government Documents Department
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The Aerodynamic Analysis of the Gyroplane Rotating-Wing System

Description: "An aerodynamic analysis of the gyroplane rotating-wing system is presented herein. This system consists of a freely rotating rotor in which opposite blades are rigidly connected and allowed to rotate or feather freely about their span axis. Equations have been derived for the lift, the lift-drag ratio, the angle of attack, the feathering angles, and the rolling and pitching moments of a gyroplane rotor in terms of its basic parameters" (p. 1).
Date: March 1934
Creator: Wheatley, John B.
Partner: UNT Libraries Government Documents Department
open access

Aerodynamic Rolling and Yawing Moments Produced by Floating Wing-Tip Ailerons, as Measured by Spinning Balance

Description: From Summary: "The investigation described in this report was made to determine the effectiveness of floating wing-tip ailerons as an airplane control in the spin. In these tests the ailerons, not being balanced, were set parallel to the axis of rotation, which is probably very nearly the attitude that balanced floating ailerons would assume in a spin. Rolling - and yawing moment coefficients are given as measured for the model with and without the ailerons, and computed values are given for th… more
Date: March 1934
Creator: Bamber, Millard J.
Partner: UNT Libraries Government Documents Department
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The Torsional Stiffness of Thin Duralumin Shells Subjected to Large Torques

Description: "This report gives a simple method of estimating the torsional stiffness of thin shells, such as box beams or stressed-skin wings under large torque loads. A general efficiency chart for shells in torsion is established, based on the assumption that the efficiency of the web sheet in resisting deformation decreases linearly with the average stress. The chart is used to calculate the torsional deflections of eight box beams, a test wing panel, and a complete wing; the results of the calculations… more
Date: July 1934
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department
open access

Tank tests of auxiliary vanes as a substitute for planing area

Description: The results of towing tests made on two models at the request of the Bureau of Aeronautics, Navy Department, are presented. The first model represents the hull of the U.S. Navy PN-8 flying boat, in which the sponsors of the original hull are removed and auxiliary lifting vanes are fitted at the chines immediately forward of the main step. The tests showed that the altered form gave a large increase in hump resistance and a very undesirable spray formation through a large part of the speed range. more
Date: February 1934
Creator: Parkinson, John B.
Partner: UNT Libraries Government Documents Department
open access

Tank tests of a family of flying-boat hulls

Description: "This report presents towing tests made in the N.A.C.A. tank of a parent form and five variations of a flying-boat hull. The beams of two of the derived forms were made the same as that of the parent and the lengths changed by increasing and decreasing the spacing of stations. The lengths of the two others of the derived forms were made the same as that of the parent while the beams were changed by increasing and decreasing the spacing of buttocks, all other widths being changed in proportion. … more
Date: February 1934
Creator: Shoemaker, James M. & Parkinson, John B.
Partner: UNT Libraries Government Documents Department
open access

A complete tank test of the hull of the Sikorsky S-40 flying boat - American Clipper Class

Description: The results of a complete test in the N.A.C.A. tank on a model of the hull of Sikorsky S-40 flying boat ('American Clipper') are reported. The test data are given in tables and curves. From these data non-dimensional coefficients are derived for use in take-off calculations and the take-off time and run for the S-40 are computed. The computed take-off time was obtained by the Sikorsky Aviation Corporation in performance tests of the actual craft.
Date: December 1934
Creator: Dawson, John R.
Partner: UNT Libraries Government Documents Department
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The Wave Suppressors Used in the N.A.C.A. Tank

Description: "So long a time was required for the disturbed water to become quiet after a model had been towed down the N.A.C.A. tank, that only 12 to 18 runs a day could be made. In order to shorten the time lost in waiting between runs, several different methods of suppressing the waves were tried. The most effective form of wave suppressor developed consists of wooden frames covered with fine copper screening and secured horizontally just beneath the surface of the water at the sides of the tank" (p. 1).
Date: December 1934
Creator: Truscott, Starr
Partner: UNT Libraries Government Documents Department
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Effect of Combustion-Chamber Shape on the Performance of a Prechamber Compression-Ignition Engine

Description: "The effect on engine performance of variations in the shape of the prechamber, the shape and direction of the connecting passage, the chamber volume using a tangential passage, the injection system, and the direction of the fuel spray in the chamber was investigated using a 5 by 7 inch single-cylinder compression-ignition engine. The results show that the performance of this engine can be considerably improved by selecting the best combination of variables and incorporating them in a single de… more
Date: December 1934
Creator: Moore, C. S. & Collins, J. H., Jr.
Partner: UNT Libraries Government Documents Department
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Complete tank tests of two flying-boat hulls with pointed steps - N.A.C.A. Models 22-A and 35

Description: "This note presents the results of complete tank test of N.A.C.A. Models 22-A and 35, two flying-boat hulls of the deep pointed-step type with low dead rise. Model 22-A is a form derived by modification of Model 22, the test results of which are given in N.A.C.A. Technical Note No. 488. Model 35 is a form of the same type but has a higher length-beam ratio than either Model 22 or 22-A. Take-off examples are worked out using data from these tests and a previous test of a conventional model appli… more
Date: September 1934
Creator: Shoemaker, James M. & Bell, Joe W.
Partner: UNT Libraries Government Documents Department
open access

The Effects of Full-Span and Partial-Span Split Flaps on the Aerodynamic Characteristics of a Tapered Wing

Description: "The investigation was made to determine the effects of full-span and of partial-span split flaps on the aerodynamic characteristics of a tapered wing. Aerodynamic force tests were made in the N.A.C.A. 7 by 10 foot wind tunnel on a highly tapered Clark Y wing equipped with various split flaps. Two sizes of tapered-chord flaps were tested as full-span flaps, and a narrow tapered-chord flap was tested as a partial-span flap by cutting off portions first from the tip and then from the center" (p. … more
Date: September 1934
Creator: Wenzinger, Carl J.
Partner: UNT Libraries Government Documents Department
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