National Advisory Committee for Aeronautics (NACA) - 74 Matching Results

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General Potential Theory of Arbitrary Wing Sections

Description: The problem of determining the two dimensional potential flow around wing sections of any shape is examined. The problem is condensed into the compact form of an integral equation capable of yielding numerical solutions by a direct process. An attempt is made to analyze and coordinate the results of earlier studies relating to properties of wing sections. The existing approximate theory of thin wing sections and the Joukowski theory with its numerous generalizations are reduced to special cases… more
Date: November 4, 1932
Creator: Theodorsen, T. & Garrick, I. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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On the plane potential flow past a lattice of arbitrary airfoils

Description: The two-dimensional, incompressible potential flow past a lattice of airfoils of arbitrary shape is investigated theoretically. The problem is treated by usual methods of conformal mapping in several stages, one stage corresponding to the mapping of the framework of the arbitrary line lattice and another significant stage corresponding to the Theodorsen method for the mapping of the arbitrary single wing profile into a circle. A particular feature in the theoretical treatment is the special han… more
Date: November 19, 1943
Creator: Garrick, I. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theoretical Prediction of Pressure Distributions on Nonlifting Airfoils at High Subsonic Speeds

Description: "Theoretical pressure distributions on nonlifting circular-arc airfoils in two-dimensional flows with high subsonic free-stream velocity are found by determining approximate solutions, through an iteration process, of an integral equation for transonic flow proposed by Oswatitsch. The integral equation stems directly from the small-disturbance theory for transonic flow. This method of analysis possesses the advantage of remaining in the physical, rather than the hodograph, variable and can be a… more
Date: November 19, 1953
Creator: Spreiter, John R. & Alksne, Alberta
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Axially Symmetric Shapes With Minimum Wave Drag

Description: "The external wave drag of bodies of revolution moving at supersonic speeds can be expressed either in terms of the geometry of the body, or in terms of the body-simulating axial source distribution. For purposes of deriving optimum bodies under various given conditions, it is found that the second of the methods mentioned is the more tractable. By use of a quasi-cylindrical theory, that is, the boundary conditions are applied on the surface of a cylinder rather than on the body itself, the var… more
Date: November 22, 1954
Creator: Heaslet, Max A. & Fuller, Franklyn B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Charts for Estimating Performance of High-Performance Helicopters

Description: "Theoretically derived charts showing the profile-drag-thrust ratio are presented for helicopter rotors operating in forward flight and having hinged rectangular blades with a linear twist of 0 degree, 8 degrees, and 16 degrees. The charts, showing the profile-drag characteristics of the rotor for various combinations of pitch angle, ratio of thrust coefficient to solidity, and a parameter representing shaft power input, are presented for tip-speed ratios ranging from 0.05 to 0.50. Also present… more
Date: November 23, 1955
Creator: Gessow, Alfred & Tapscott, Robert J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Derivation of charts for determining the horizontal tail load variation with any elevator motion

Description: From Summary: "The equations relating the wing and tail loads are derived for a unit elevator displacement. These equations are then converted into a nondimensional form and charts are given by which the wing- and tail-load-increment variation may be determined under dynamic conditions for any type of elevator motion and for various degrees of airplane stability. In order to illustrate the use of the charts, several examples are included in which the wing and tail loads are evaluated for a numb… more
Date: November 23, 1942
Creator: Pearson, Henry A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Identification of knock in NACA high-speed photographs of combustion in a spark-ignition engine

Description: Report presents the results of a study of combustion in a spark-ignition engine given in NACA Technical Reports 704 and 727. The present investigation was made with the NACA high-speed motion-picture camera, operating at 40,000 photographs a second, and with a cathode-ray oscillograph operating on a piezoelectric pick-up in the combustion chamber. Photographs are presented showing that the origin of knock is not necessarily in the end gas. The data obtained indicates that knock takes place only… more
Date: November 14, 1942
Creator: Miller, Cearcy D. & Olsen, H. Lowell
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Theoretical Investigation of the Rolling Oscillations of an Airplane With Ailerons Free

Description: "An analysis is made of the stability of an airplane with ailerons free, with particular attention to the motions when the ailerons have a tendency to float against the wind. The present analysis supersedes the aileron investigation contained in NACA Technical Report no. 709. The equations of motion are first written to include yawing and sideslipping, and it is demonstrated that the principal effects of freeing the ailerons can be determined without regard to these motions" (p. 255).
Date: November 19, 1943
Creator: Cohen, Doris
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Method of Matching Performance of Compressor Systems with that of Aircraft Power Sections

Description: "A method is developed of easily determining the performance of a compressor system relative to that of the power section for a given altitude. Because compressors, reciprocating engines, and turbines are essentially flow devices, the performance of each of these power-plant components is presented in terms of similar dimensionless ratios. The pressure and temperature changes resulting from restrictions of the charge-air flow and from heat transfer in the ducts connecting the components of the … more
Date: November 15, 1945
Creator: Bullock, Robert O.; Keetch, Robert C. & Moses, Jason J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Application of Spring Tabs to Elevator Controls

Description: Equations are presented for calculating the stick-force characteristics obtained with a spring-tab type of elevator control. The main problems encountered in the design of a satisfactory elevator spring tab are to provide stick forces in the desired range, to maintain the force per g sufficiently constant throughout the speed range, to avoid undesirable "feel" of the control in ground handling or in flight at low airspeeds, and to prevent flutter. Examples are presented to show the design featu… more
Date: November 24, 1944
Creator: Phillips, William H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Charts for the Determination of Wing Torsional Stiffness Required for Specified Rolling Characteristics or Aileron Reversal Speed

Description: From Summary :"A series of charts are presented by which the wing torsional stiffness required to meet a given standard of rolling effectiveness may be quickly determined. The charts may also be used to obtain quickly the aileron reversal speed and the variation of the loss in rolling effectiveness with airspeed. The charts apply to linearly tapered wings and elliptical wings of tubular-shell construction having various aspect ratios with aileron span and location of ailerons as variables. In t… more
Date: November 9, 1944
Creator: Pearson, Henry A. & Aiken, William S., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A graphical method of determining pressure distribution in two-dimensional flow

Description: By a generalization of the Joukowski method, a procedure is developed for effecting localized modifications of airfoil shapes and for determining graphically the resultant changes in the pressure distribution. The application of the procedure to the determination of the pressure distribution over airfoils of original design is demonstrated. Formulas for the lift, the moment, and the aerodynamic center are also given.
Date: November 12, 1940
Creator: Jones, Robert T. & Cohen, Doris
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The calculation of downwash behind supersonic wings with an application to triangular plan forms

Description: A method is developed consistent with the assumptions of small perturbation theory which provides a means of determining the downwash behind a wing in supersonic flow for a known load distribution. The analysis is based upon the use of supersonic doublets which are distributed over the plan form and wake of the wing in a manner determined from the wing loading. The equivalence in subsonic and supersonic flow of the downwash at infinity corresponding to a given load distribution is proved.
Date: November 9, 1948
Creator: Lomax, Harvard; Sluder, Loma & Heaslet, Max A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of afterbody length and keel angle on minimum depth of step for landing stability and on take-off stability of a flying boat

Description: From Summary: "Tests were made to fill partly the need for information on the effect of afterbody dimensions on the hydrodynamic stability of a flying boat in smooth water. The dimensions investigated were depth of step, angle of afterbody keel, and length of afterbody. An analysis of the data showed that as either the afterbody length or keel angle was increased an accompanying increase in depth of step was required in order to maintain adequate landing stability."
Date: November 13, 1947
Creator: Olson, Roland E. & Land, Norman S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Analysis of effect of basic design variables on subsonic axial-flow-compressor performance

Description: From Summary: "A blade-element theory for axial-flow compressors has been developed and applied to the analysis of the effects of basic design variables such as Mach number, blade loading, and velocity distribution on compressor performance. The relations among several efficiencies useful in compressor design are derived and discussed. The possible gains in useful operating range obtainable by the use of adjustable stator blades are discussed and a rapid approximate method of calculating blade-… more
Date: November 26, 1947
Creator: Sinnette, John T., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Stability derivatives of triangular wings at supersonic speeds

Description: "The analysis of the stability derivatives of low-aspect-ratio triangular wings at subsonic and supersonic speeds, given in NACA TN no. 1423, is extended to apply to triangular wings having large vertex angles and traveling at supersonic speeds. The lift, rolling moment due to sideslip, and damping in roll and pitch for this more general case have been treated elsewhere on the basis of the theory of small disturbances. The surface potentials for angle of attack and rolling taken therefrom are u… more
Date: November 6, 1947
Creator: Ribner, Herbert S. & Malvestuto, Frank S., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Correlation of the drag characteristics of a typical pursuit airplane obtained from high-speed wind-tunnel and flight tests

Description: In order to obtain a correlation of drag data from wind-tunnel and flight tests at high Mach numbers, a typical pursuit airplane, with the propeller removed, was tested in flight at Mach numbers up to 0.755, and the results were compared with wind-tunnel tests of a 1/3-scale model of the airplane. The tests results show that the drag characteristics of the test airplane can be predicted with satisfactory accuracy from tests in the Ames 16-foot high-speed wind tunnel of the Ames Aeronautical Lab… more
Date: November 2, 1944
Creator: Nissen, James M.; Gadeberg, Burnett L. & Hamilton, William T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of NACA Injection Impeller on Mixture Distribution of Double-Row Radial Aircraft Engine

Description: "The NACA injection impeller was developed to improve the mixture distribution of aircraft engines by discharging the fuel from a centrifugal supercharger impeller and thus to promote a thorough mixing of fuel and charge air. Experiments with a double-row radial aircraft engine indicated that for the normal range of engine power the NACA injection impeller provided marked improvement in mixture distribution over the standard spray-bar injection system used in the same engine. The mixture distri… more
Date: November 14, 1945
Creator: Marble, Frank E.; Ritter, William K. & Miller, Mahlon A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experimental verification of a simplified vee-tail theory and analysis of available data on complete models with vee tails

Description: An analysis has been made of available data on vee tail surfaces. Previously published theoretical studies of vee tails have been extended to include the control effectiveness and control forces in addition to the stability. Tests of two isolated tail surfaces with various amounts of dihedral provided a check of the theory. Methods for designing vee tails were also developed and are given in the present paper.
Date: November 14, 1944
Creator: Purser, Paul E. & Campbell, John P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Critical combinations of shear and transverse direct stress for an infinitely long flat plate with edges elastically restrained against rotation

Description: An exact solution and a closely concurring approximate energy solution are given for the buckling of an infinitely long flat plate under combined shear and transverse direct stress with edges elastically restrained against rotation. It was found that an appreciable fraction of the critical stress in pure shear may be applied to the plate without any reduction in the transverse compressive stress necessary to produce buckling. An interaction formula in general use was shown to be decidedly conse… more
Date: November 8, 1944
Creator: Batdorf, S. B. & Houbolt, John C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The NACA high-speed motion-picture camera optical compensation at 40,000 photographs per second

Description: The principle of operation of the NACA high-speed camera is completely explained. This camera, operating at the rate of 40,000 photographs per second, took the photographs presented in numerous NACA reports concerning combustion, preignition, and knock in the spark-ignition engine. Many design details are presented and discussed, details of an entirely conventional nature are omitted. The inherent aberrations of the camera are discussed and partly evaluated. The focal-plane-shutter effect of th… more
Date: November 6, 1945
Creator: Miller, Cearcy D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Tank Investigation of a Powered Dynamic Model of a Large Long-Range Flying Boat

Description: "Principles for designing the optimum hull for a large long-range flying boat to meet the requirements of seaworthiness, minimum drag, and ability to take off and land at all operational gross loads were incorporated in a 1/12-size powered dynamic model of a four-engine transport flying boat having a design gross load of 165,000 pounds. These design principles included the selection of a moderate beam loading, ample forebody length, sufficient depth of step, and close adherence to the form of a… more
Date: November 29, 1946
Creator: Parkinson, John B.; Olson, Roland E. & Haar, Marvin I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Application of a channel design method to high-solidity cascades and tests of an impulse cascade with 90 degrees of turning

Description: From introduction: "A technique for application of the channel design methods of reference 11 to the design of high-solidity cascades with prescribed velocity distributions as a function of arc length along the blade-element profiles is presented herein."
Date: November 30, 1951
Creator: Stanitz, John D. & Sheldrake, Leonard J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Method for calculating lift distributions for unswept wings with flaps or ailerons by use of nonlinear section lift data

Description: A method is presented which allows the use of nonlinear section lift data in the calculation of the spanwise lift distribution of unswept wings with flaps or ailerons. This method is based upon lifting line theory and is an extension to the method described in NACA rep. 865. The mathematical treatment of the discontinuity in absolute angle of attack at the end of the flap or aileron involves the use of a correction factor which accounts for the inability of a limited trigonometric series to rep… more
Date: November 13, 1950
Creator: Sivells, James C. & Westrick, Gertrude C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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