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  Partner: UNT Libraries Government Documents Department
 Decade: 1930-1939
 Collection: Technical Report Archive and Image Library
The aerodynamic analysis of the gyroplane rotating-wing system

The aerodynamic analysis of the gyroplane rotating-wing system

Date: March 1, 1934
Creator: Wheatley, John B
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. Curves of lift-drag ratio against lift coefficient have been calculated for a typical case, showing the effect of varying the pitch angle, the solidarity, and the average blade-section drag coefficient. The analysis expresses satisfactorily the qualitative relations between the rotor characteristics and the rotor parameters. As disclosed by this investigation, the aerodynamic principles of the gyroplane are sound, and further research on this wing system is justified.
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The aerodynamic aspect of wing-fuselage fillets

The aerodynamic aspect of wing-fuselage fillets

Date: February 1, 1935
Creator: Muttray, H
Description: 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.
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Aerodynamic characteristics of a 4-engine monoplane showing comparison of air-cooled and liquid-cooled engine installations

Aerodynamic characteristics of a 4-engine monoplane showing comparison of air-cooled and liquid-cooled engine installations

Date: July 1, 1939
Creator: Wilson, Herbert A , Jr & Silverstein, Abe
Description: None
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Aerodynamic characteristics of a 4-engine monoplane showing effects of enclosing the engines in the wing and comparisons of tractor- and pusher-propeller arrangements

Aerodynamic characteristics of a 4-engine monoplane showing effects of enclosing the engines in the wing and comparisons of tractor- and pusher-propeller arrangements

Date: April 1, 1938
Creator: Wilson, Herbert A , Jr
Description: None
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Aerodynamic characteristics of a large number of airfoils tested in the variable-density wind tunnel

Aerodynamic characteristics of a large number of airfoils tested in the variable-density wind tunnel

Date: January 1, 1938
Creator: Pinkerton, Robert M & Greenberg, Harry
Description: The aerodynamic characteristics of a large number of miscellaneous airfoils tested in the variable-density tunnel have been reduced to a comparable form and are published in this report for convenient reference. Plots of the standard characteristics are given in tabular form. Included is a tabulation of important characteristics for the related airfoils reported in NACA report 460. This report, in conjunction with NACA report 610, makes available in comparable and convenient form the aerodynamic data for airfoils tested in the variable-density tunnel since January 1, 1931.
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The aerodynamic characteristics of a model wing having a split flap deflected downward and moved to the rear

The aerodynamic characteristics of a model wing having a split flap deflected downward and moved to the rear

Date: May 1, 1932
Creator: Weick, Fred E & Harris, Thomas E
Description: Tests were made on a model wing with three different sized split trailing-edged flaps, in the NACA 7 by 10 foot wind tunnel. The flaps were formed of the lower rear portion of the wing and were rotated downward about axes at their front edges. The lift, drag, and center of pressure were measured with the axis in its original position and also with it moved back in even steps to the trailing edge of the main wing, giving in effect an increase in area. The split flaps when deflected about their original axis locations gave slightly higher maximum lift coefficients than conventional trailing-edge flaps, and the lift coefficients were increased still further by moving the axes toward the rear. The highest value of C(sub L max), which was obtained with the largest flap hinged at 90 per cent of the chord from the leading edge, was 2.52 as compared with 1.27 for the basic wing.
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The aerodynamic characteristics of a slotted Clark y wing as affected by the auxiliary airfoil position

The aerodynamic characteristics of a slotted Clark y wing as affected by the auxiliary airfoil position

Date: January 1, 1932
Creator: Wenzinger, Carl J & Shortal, Joseph A
Description: Aerodynamic force tests on a slotted Clark Y wing were conducted in a vertical wind tunnel to determine the best position for a given auxiliary airfoil with respect to the main wing. A systematic series of 100 changes in location of the auxiliary airfoil were made to cover all the probable useful ranges of slot gap, slot width, and slot depth. The results of the investigation may be applied to the design of automatic or controlled slots on wings with geometric characteristics similar to the wing tested. The best positions of the auxiliary airfoil were covered by the range of the tests, and the position for desired aerodynamic characteristics may easily be obtained from charts prepared especially for the purpose.
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Aerodynamic characteristics of a wing with Fowler flaps including flap loads, downwash, and calculated effect on take-off

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

Date: January 1, 1936
Creator: Platt, Robert C
Description: 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.
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The aerodynamic characteristics of airfoils as affected by surface roughness

The aerodynamic characteristics of airfoils as affected by surface roughness

Date: April 1, 1933
Creator: HOCKER RAY W
Description: The effect on airfoil characteristics of surface roughness of varying degrees and types at different locations on an airfoil was investigated at high values of the Reynolds number in a variable density wind tunnel. Tests were made on a number of National Advisory Committee for Aeronautics (NACA) 0012 airfoil models on which the nature of the surface was varied from a rough to a very smooth finish. The effect on the airfoil characteristics of varying the location of a rough area in the region of the leading edge was also investigated. Airfoils with surfaces simulating lap joints were also tested. Measurable adverse effects were found to be caused by small irregularities in airfoil surfaces which might ordinarily be overlooked. The flow is sensitive to small irregularities of approximately 0.0002c in depth near the leading edge. The tests made on the surfaces simulating lap joints indicated that such surfaces cause small adverse effects. Additional data from earlier tests of another symmetrical airfoil are also included to indicate the variation of the maximum lift coefficient with the Reynolds number for an airfoil with a polished surface and with a very rough one.
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The aerodynamic characteristics of airfoils at negative angles of attack

The aerodynamic characteristics of airfoils at negative angles of attack

Date: March 1, 1932
Creator: Anderson, Raymond F
Description: A number of airfoils, including 14 commonly used airfoils and 10 NACA airfoils, were tested through the negative angle-of-attack range in the NACA variable-density wind tunnel at a Reynolds Number of approximately 3,000,000. The tests were made to supply data to serve as a basis for the structural design of airplanes in the inverted flight condition. In order to make the results immediately available for this purpose they are presented herein in preliminary form, together with results of previous tests of the airfoils at positive angles of attack. An analysis of the results made to find the variation of the ratio of the maximum negative lift coefficient to the maximum positive lift coefficient led to the following conclusions: 1) For airfoils of a given thickness, the ratio -C(sub L max) / +C(sub L max) tends to decrease as the mean camber is increased. 2) For airfoils of a given mean camber, the ratio -C(sub L max) / +C(sub L max) tends to increase as the thickness increases.
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Aerodynamic characteristics of airfoils VI : continuation of reports nos. 93, 124, 182, 244, and 286

Aerodynamic characteristics of airfoils VI : continuation of reports nos. 93, 124, 182, 244, and 286

Date: January 1, 1930
Creator: unknown
Description: This collection of data on airfoils has been made from the published reports of a number of the leading aerodynamic laboratories of this country and Europe. The information which was originally expressed according to the different customs of the several laboratories is here presented in a uniform series of charts and tables suitable for use of designing engineers and for purposes of general reference. The authority for the results here presented is given as the name of the laboratory at which the experiments were conducted, with the size of the model, wind velocity, and year of test.
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Aerodynamic characteristics of anemometer cups

Aerodynamic characteristics of anemometer cups

Date: February 1, 1934
Creator: Brevoort, M J & Joyner, U T
Description: The static lift and drag forces on three hemispherical and two conical cups were measured over a range of angles of attack from 0 degrees to 180 degrees and a range of Reynolds Numbers from very small up to 400,000. The problems of supporting the cup for measurement and the effect of turbulence were also studied. The results were compared with those of other investigators.
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Aerodynamic characteristics of circular-arc airfoils at high speeds

Aerodynamic characteristics of circular-arc airfoils at high speeds

Date: January 1, 1932
Creator: Briggs, L. J. & Dryden, H. L.
Description: The aerodynamic characteristics of eight circular-arc airfoils at speeds of 0.5, 0.8, 0.95, and 1.08 times the speed of sound have been determined in an open-jet air stream 2 inches in diameter, using models of 1-inch chord. The lower surface of each airfoil was plane; the upper surface was cylindrical. As compared with the measurements described in NACA-TR-319, the circular-arc airfoils at speeds of 0.95 and 1.08 times the speed of sound are more efficient than airfoils of the R. A. F. or Clark Y families. At a speed of 0.5 times the speed of sound, the thick circular-arc sections are extremely inefficient, but thin sections compare favorably with those of the R. A. F. family. A moderate round of the sharp edges changes the characteristics very little and is in many instances beneficial. The results indicate that the section of the blades of propellers intended for use at high tip-speeds should be of the circular-arc form for the outer part of the blade and should be changed gradually to the R. A. F. or Clark Y form as the hub is approached.
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The aerodynamic characteristics of eight very thick airfoils from tests in the variable density wind tunnel

The aerodynamic characteristics of eight very thick airfoils from tests in the variable density wind tunnel

Date: January 1, 1932
Creator: Jacobs, Eastman N
Description: Report presents the results of wind tunnel tests on a group of eight very thick airfoils having sections of the same thickness as those used near the roots of tapered airfoils. The tests were made to study certain discontinuities in the characteristic curves that have been obtained from previous tests of these airfoils, and to compare the characteristics of the different sections at values of the Reynolds number comparable with those attained in flight. The discontinuities were found to disappear as the Reynolds number was increased. The results obtained from the large-scale airfoil, a symmetrical airfoil having a thickness ratio of 21 per cent, has the best general characteristics.
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The aerodynamic characteristics of four full-scale propellers having different plan forms

The aerodynamic characteristics of four full-scale propellers having different plan forms

Date: January 1, 1938
Creator: Hartman, Edwin P & Biermann, David
Description: Tests were made of four propellers, with diameters of 10 feet, having different blade plan forms. One propeller (Navy design no. 5868-r6) was of the usual present-day type and was used as a basis of comparison for the other three, which had unusual plan forms distinguished by the inward (toward the hub) location of the sections having the greatest blade width. It was found that propellers with points of maximum blade width occurring closer to the hub than on the present-day type of blade had higher peak efficiencies but lower take-off efficiencies. This results was found true for a "clean" liquid-cooled engine installation. It appears that some modification could be made to present plan forms which would produce propellers having more satisfactory aerodynamic qualities. The propellers with the inward location of the points of maximum blade width had lower thrust and power coefficients and stalled earlier than the present-day type.
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The aerodynamic characteristics of full-scale propellers having 2, 3, and 4 blades of Clark y and R.A.F. 6 airfoil sections

The aerodynamic characteristics of full-scale propellers having 2, 3, and 4 blades of Clark y and R.A.F. 6 airfoil sections

Date: January 1, 1938
Creator: Hartman, Edwin P & Biermann, David
Description: Aerodynamic tests were made of seven full-scale 10-foot-diameter propellers of recent design comprising three groups. The first group was composed of three propellers having Clark y airfoil sections and the second group was composed of three propellers having R.A.F. 6 airfoil sections, the propellers of each group having 2, 3, and 4 blades. The third group was composed of two propellers, the 2-blade propeller taken from the second group and another propeller having the same airfoil section and number of blades but with the width and thickness 50 percent greater. The tests of these propellers reveal the effect of changes in solidity resulting either from increasing the number of blades or from increasing the blade width propeller design charts and methods of computing propeller thrust are included.
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Aerodynamic characteristics of NACA 23012 and 23021 airfoils with 20-percent-chord external-airfoil flaps of NACA 23012 section

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

Date: January 1, 1937
Creator: Platt, Robert C & Abbott, Ira H
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.
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Aerodynamic characteristics of several airfoils of low aspect ratio

Aerodynamic characteristics of several airfoils of low aspect ratio

Date: August 1, 1935
Creator: Zimmerman, C H
Description: 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.
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The aerodynamic characteristics of six commonly used Airfoils over a large range of positive and negative angles of attack

The aerodynamic characteristics of six commonly used Airfoils over a large range of positive and negative angles of attack

Date: November 1, 1931
Creator: Anderson, Raymond F
Description: This paper presents the results of tests of six commonly used airfoils: the CYH, the N-22, the C-72, the Boeing 106, and the Gottingen 398. The lifts, drags, and pitching moments of the airfoils were measured through a large range of positive and negative angles of attack. The tests were made in the variable density wind tunnel of the National Advisory Committee for Aeronautics at a large Boeing 106, and the Gottingen 398 airfoils, the negative maximum lift coefficients were found to be approximately half the positive; but for the M-6 and the CYH, which have less effective values were, respectively, 0.8 and 0.6 of the positive values.
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The aerodynamic characteristics of six full-scale propellers having different airfoil sections

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

Date: January 1, 1939
Creator: Biermann, David & Hartman, Edwin P
Description: 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.
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The aerodynamic characteristics of three tapered airfoils tested in the variable density wind tunnel

The aerodynamic characteristics of three tapered airfoils tested in the variable density wind tunnel

Date: February 1, 1931
Creator: Anderson, Raymond F
Description: This report contains the lift, drag, and moment characteristics of tapered Clark Y, Gottingen 393, and USA 45 airfoils as obtained from tests made in the Variable Density Wind Tunnel of the NACA. The results are given at both low and high Reynolds Numbers to show scale effect and to provide data for use in airplane design.
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Aerodynamic characteristics of twenty-four airfoils at high speeds

Aerodynamic characteristics of twenty-four airfoils at high speeds

Date: January 1, 1930
Creator: Brigg, L. J. & Dryden, H. L.
Description: The aerodynamic characteristics of 24 airfoils are given for speeds of 0.5, 0.65, 0.8, 0.95, and 1.08 times the speed of sound, as measured in an open-jet air stream 2 inches in diameter, using models of 1-inch chord. The 24 airfoils belong to four general groups. The first is the standard R. A. F. family in general use by the Army and Navy for propeller design, the members of the family differing only in thickness. This family is represented by nine members ranging in thickness from 0.04 to 0.20 inch. The second group consists of five members of the Clark Y family, the members of the family again differing only in thickness. The third group, comprising six members, is a second R. A. F. Family in which the position of the maximum ordinate is varied. Combined with two members of the first R.A.F. family, this group represents a variation of maximum ordinate position from 30 to 60 percent of the chord in two camber ratios, 0.08 and 0.16. The fourth group consists of three geometrical forms, a flat plate, a wedge, and a segment of a right circular cylinder. In addition one section used in the reed metal propeller was ...
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Aerodynamic characteristics of wings with cambered external airfoil flaps, including lateral control, with a full-span flap

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

Date: January 1, 1936
Creator: Platt, Robert C
Description: 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.
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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.
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