UNT Libraries Government Documents Department - 111 Matching Results

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Removing boundary layer by suction

Description: "Through the utilization of the "Magnus effect" on the Flettner rotor ship, the attention of the public has been directed to the underlying physical principle. It has been found that the Prandtl boundary-layer theory furnishes a satisfactory explanation of the observed phenomena. The present article deals with the prevention of this separation or detachment of the flow by drawing the boundary layer into the inside of a body through a slot or slots in its surface" (p. 1).
Date: January 1926
Creator: Ackeret, J.
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The Glider of the College Aviation Group of the Technical High School, Hanover

Description: This report presents the results of testing on a glider designed and built by the College Aviation Group. The design and construction were based on the following principles: 1) the glider will be made to descend as slowly as possible; 2) rigidity and resistance were arranged to meet the conditions of varied loads; 3) construction is as simple as possible; 4) and great ease in assembling and dismounting have been sought.
Date: January 1922
Creator: Blume, W.
open access

Efflux of Gases Through Small Orifices

Description: Scientific paper issued by the Bureau of Standards over studies conducted on gas effusion rates. The methods used and the results of the studies are presented and discussed. This paper includes tables, and illustrations.
Date: January 28, 1920
Creator: Buckingham, Edgar & Edwards, Junius David
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Bending moments, envelope, and cable stresses in non-rigid airships

Description: This report describes the theory of calculating the principal stresses in the envelope of a nonrigid airship used by the Bureau of Aeronautics, United States Navy. The principal stresses are due to the gas pressure and the unequal distribution of weight and buoyancy, and the concentrated loads from the car suspension cables. The second part of the report deals with the variations of tensions in the car suspension cables of any type of airship, with special reference to the rigid type, due to th… more
Date: January 1923
Creator: Burgess, C. P.
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The Effect on Performance of a Cutaway Center Section

Description: "The assumption is made that a skeleton or cutaway center section is desirable for forward vision and to determine the effect of such mutilation upon performance the following work was done. The airplane used was a Vought VE-7 and in addition to the cutaway center section a system of end plates or fins was installed. Various conditions and combinations were investigated in level flight and in climb" (p. 1).
Date: January 1928
Creator: Carroll, Thomas
open access

Damping Coefficients Due to Tail Surfaces in Aircraft

Description: "The object of the investigation described in this report was to compare the damping coefficients of an airfoil as calculated from a knowledge of the static characteristics of the section with those obtained experimentally with an oscillation. The damping coefficients as obtained, according to the conventional notation, can be considered either as due to pitching or as due to yawing, the oscillation in these experiments being so arranged that the surfaces oscillate about a vertical axis. This i… more
Date: January 1, 1923
Creator: Chu, Lynn
open access

New Lateral Stabilizing Device for Airplanes

Description: "The proposed device tends to render the lateral stabilization of airplanes easier and more efficacious. The proposed solution is to mount the ailerons independently, in such a manner that they can turn freely, under the action of the relative wind, about an axis located in front of the extreme position of the center of the lift" (p. 1).
Date: January 1921
Creator: Constantin, Louis
open access

The Dead Weight of the Airship and the Number of Passengers That Can Be Carried

Description: In order to determine an approximate formula giving the weight of a dead load as a function of the volume (V) of the envelope and of the maximum velocity (v), we will take the relative weight of the various parts of the airship (P(sub v), M, V, A, T(sup 34)), adopting a mean value of the coefficients determined. This formula may be adopted both for semi-rigid airships with suspended nacelle and non-rigid envelope, with or without internal suspensions. It may also be adapted to airships with rig… more
Date: January 1922
Creator: Crocco
open access

Investigation of Slipstream Velocity

Description: "These experiments were made at the request of the Bureau of Aeronautics, Navy Department, to investigate the velocity of the air in the slipstream in horizontal and climbing flight to determine the form of expression giving the slipstream velocity in terms of the airspeed of the airplane. The method used consisted in flying the airplane both on a level course and in climb at full throttle and measuring the slipstream velocity at seven points in the slipstream for the whole speed range of the a… more
Date: January 1925
Creator: Crowley, J. W., Jr.
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Pressure Distribution Over a Wing and Tail Rib of a VE-7 and of a TS Airplane in Flight

Description: "This investigation was made to determine the pressure distribution over a rib of the wing and over a rib of the horizontal tail surface of an airplane in flight and to obtain information as to the time correlation of the loads occurring on these ribs. Two airplanes, VE-7 and TS, were selected in order to obtain the information for a thin and a thick wing section. In each case the pressure distribution was recorded for the full range of angle of attack in level flight and throughout violent man… more
Date: January 1928
Creator: Crowley, J. W., Jr.
open access

Characteristics of a boat type seaplane during take-off

Description: This report, on the planing and get-away characteristics of the F-5-L, gives the results of the second of a series of take-off tests on three different seaplanes conducted by the National Advisory Committee for Aeronautics at the suggestion of the Bureau of Aeronautics, Navy Department. The single-float seaplane was the first tested and the twin-float seaplane is to be the third. The characteristics of the boat type were found to be similar to the single float, the main difference being the inc… more
Date: January 1926
Creator: Crowley, J. W., Jr. & Ronan, K. M.
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Characteristics of a single float seaplane during take-off

Description: At the request of the Bureau of Aeronautics, Navy Department, the National Advisory Committee for Aeronautics at Langley Field is investigating the get-away characteristics of an N-9H, a DT-2, and an F-5l, as representing, respectively, a single float, a double float, and a boat type of seaplane. This report covers the investigation conducted on the N-9H. The results show that a single float seaplane trims aft in taking off. Until a planing condition is reached the angle of attack is about 15 d… more
Date: January 1925
Creator: Crowley, J. W., Jr. & Ronan, K. M.
open access

Characteristics of a twin-float seaplane during take-off

Description: This report presents the results of an investigation of the planing and get-away characteristics of three representative types of seaplanes, namely, single float, boat, and twin float. The experiments carried out on the single float and boat types have been reported on previously. This report covers the investigation conducted on the twin-float seaplane, the DT-2, and includes as an appendix, a brief summary of the results obtained on all three tests. At low-water speeds, 20 to 30 miles per hou… more
Date: January 1927
Creator: Crowley, John W., Jr. & Ronan, K. M.
open access

The determination of the effective resistance of a spindle supporting a model aerofoil

Description: An attempt was made to determine the effect of spindle interference on the lift of the airfoil by measuring moments about the axis parallel to the direction of air flow. The values obtained are of the same degree as the experimental error, and for the present this effect will be neglected. The results obtained using a U.S.A. 15 wing (plotted here) show that the correction is nearly constant from 0 degrees to 10 degrees incidence and that at greater angles its value becomes erratic. At such angl… more
Date: January 1921
Creator: Davidson, W. E. & Bacon, D. L.
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Marcel Besson Wing Sections

Description: Three different Marcel Besson airfoils are investigated in terms of maximum lift, maximum fineness, minimum required power, and wing section drag. Comparisons are then made between the three airfoils.
Date: January 1923
Creator: Delanghe, C.
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Comparison of hecter fuel with export aviation gasoline

Description: Among the fuels which will operate at compression ratios up to at least 8.0 without preignition or "pinking" is hecter fuel, whence a careful determination of its performance is of importance. For the test data presented in this report the hecter fuel used was a mixture of 30 per cent benzol and 70 per cent cyclohexane, having a low freezing point, and distilling from first drop to 90 per cent at nearly a constant temperature, about 20 degrees c. below the average distillation temperature ("mea… more
Date: January 29, 1920
Creator: Dickinson, H. C.; Gage, V. R. & Sparrow, S. W.
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The application of propeller test data to design and performance calculations

Description: From Summary: "This report is a study of a test data on a family of Durand's propellers (nos. 3, 7, 11, 82, 113, 139), which is fairly representative of conventional design. The test data are so plotted that the proper pitch and diameters for any given set of conditions are readily obtained. The same data are plotted in other forms which may be used for calculating performance when the ratio of pitch to diameter is known. These new plots supply a means for calculating the performance, at any al… more
Date: January 1925
Creator: Diehl, Walter S.
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Charts for graphical estimation of airplane performance

Description: This report contains a series of charts which were developed in order to simplify the estimation of airplane performance. Charts are given for estimating propeller diameter and efficiency, maximum speed, initial rate of climb, absolute ceiling, service ceiling, climb in 10 minutes, time to climb to any altitude, maximum speed at any altitude, and endurance. A majority of these charts are based on the equations given in NACA Technical Report no. 173. Plots of pressure and density against altitud… more
Date: January 1925
Creator: Diehl, Walter S.
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The determination of downwash

Description: It is obvious that, in accordance with Newton's second law, the lift on an aerofoil must be equal to the vertical momentum communicated per second to the air mass affected. Consequently a lifting aerofoil in flight is trailed by a wash which has a definite inclination corresponding to the factors producing the lift. It is thought that sufficient data, theoretical and experimental, are now available for a complete determination of this wash with respect to the variation of its angle of inclinati… more
Date: January 1921
Creator: Diehl, Walter S.
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Effect of aerofoil aspect ratio on the slope of the lift curve

Description: On of the most important characteristics of an airfoil is the rate of change of lift with angle of attack, (sup dC)L/d alpha. This factor determines the effectiveness of a tail plane in securing static longitudinal stability. The application of the Gottingen formulas given here for calculating the variation of (sup Dc)L/d alpha with aspect ratio should be of interest to many aeronautical engineers. For the convenience of the engineer, a set of curves calculated by the method set forth here are … more
Date: January 1922
Creator: Diehl, Walter S.
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