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Determination of vortex paths by series expansion technique with application to cruciform wings

Description: A series method of determining two-dimensional vortex paths is considered and applied to the computation of vortex positions behind a slender equal-span cruciform wing at any angle of bank as a function of the distance behind the trailing edge. Calculated paths are shown for four bank angles. For a bank angle of 45 degrees comparison is made with the results of a closed expression given in NACA-TN-2605. For other bank angles water-tank experiments provide qualitative comparison. Satisfactory ag… more
Date: February 8, 1956
Creator: Alksne, Alberta Y.
Item Type: Refine your search to only Report
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Exploratory investigation of boundary-layer transition on a hollow cylinder at a Mach number of 6.9

Description: Report presenting an investigation of the Reynolds number for transition on the outside of a hollow cylinder with heat transfer from the boundary layer to the wall at Mach number 6.9. At a given Mach number, it appears that the Reynolds number based on leading-edge thickness is an important parameter in comparisons of flat-plate transition data from various installations.
Date: February 9, 1956
Creator: Bertram, Mitchel H.
Item Type: Refine your search to only Report
open access

An experimental investigation of sting-support effects on drag and a comparison with jet effects at transonic speeds

Description: Various dummy stings were tested on the rear of a related series of afterbody shapes for Mach numbers from 0.80 to 1.10 and Reynolds numbers based on body length from 15.0 x 16 to the 6th power to 17.4 x 10 to the 6th power. A method is presented whereby approximate sting interference corrections can be made to models having afterbody shapes and sting supports similar to those of these tests if the Reynolds numbers are of the same order of magnitude and a turbulent boundary layer exists at the … more
Date: June 4, 1956
Creator: Cahn, Maurice S.
Item Type: Refine your search to only Report
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Some possibilities of using gas mixtures other than air in aerodynamic research

Description: A study is made of the advantages that can be realized in compressible-flow research by employing a substitute heavy gas in place of air. The present report is based on the idea that by properly mixing a heavy monatomic gas with a suitable heavy polyatomic gas, it is possible to obtain a heavy gas mixture which has the correct ratio of specific heats and which is nontoxic, nonflammable, thermally stable, chemically inert, and comprised of commercially available components. Calculations were mad… more
Date: 1956
Creator: Chapman, Dean R.
Item Type: Refine your search to only Report
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Investigation of separated flows in supersonic and subsonic streams with emphasis on the effect of transition

Description: Report presents the results of experimental and theoretical research conducted on flow separation associated with steps, bases, compression corners, curved surfaces, shock-wave boundary-layer reflections, and configurations producing leading-edge separation. Results were obtained from pressure-distribution measurements, shadowgraph observations, high-speed motion pictures, and oil-film studies. The maximum scope of measurement encompassed Mach numbers between 0.4 and 3.6, and length Reynolds nu… more
Date: November 29, 1956
Creator: Chapman, Dean R.; Kuehn, Donald M. & Larson, Howard K.
Item Type: Refine your search to only Report
open access

Theory of self-excited mechanical oscillations of helicopter rotors with hinged blades

Description: Vibrations of rotary-wing aircraft may derive their energy from the rotation of the rotor rather than from the air forces. A theoretical analysis of these vibrations is described and methods for its application are explained in Chapter one. Chapter two reports the results of an investigation of the mechanical stability of a rotor having two vertically hinged blades mounted upon symmetrical supports, that is, of equal stiffness and mass in all horizontal directions. Chapter three presents the th… more
Date: August 24, 1956
Creator: Coleman, Robert P. & Feingold, Arnold M.
Item Type: Refine your search to only Report
open access

Investigation of the Laminar Aerodynamic Heat-Transfer Characteristics of a Hemisphere-Cylinder in the Langley 11-inch Hypersonic Tunnel at a Mach Number of 6.8

Description: "A program to investigate the aerodynamic heat transfer of a nonisothermal hemisphere-cylinder has been conducted in the Langley 11-inch hypersonic tunnel at a Mach number of 6.8 and a Reynolds number from approximately 0.14 x 10(6) to 1.06 x 10(6) based on diameter and free-stream conditions. The experimental heat-transfer coefficients were slightly less over the whole body than those predicted by the theory of Stine and Wanlass (NACA technical note 3344) for an isothermal surface. For station… more
Date: March 21, 1956
Creator: Crawford, Davis H. & McCauley, William D.
Item Type: Refine your search to only Report
open access

The response of an airplane to random atmospheric disturbances

Description: The statistical approach to the gust-load problem, which consists in considering flight through turbulent air to be a stationary random process, is extended by including the effect of lateral variation of the instantaneous gust intensity on the aerodynamic forces. The forces obtained in this manner are used in dynamic analyses of rigid and flexible airplanes free to move vertically, in pitch, and in roll. The effect of the interaction of longitudinal, normal, and lateral gusts on the wind stres… more
Date: November 5, 1956
Creator: Diederich, Franklin W.
Item Type: Refine your search to only Report
open access

Comparison of several methods for obtaining the time response of linear systems to either a unit impulse or arbitrary input from frequency-response data

Description: From Summary: "Several methods of obtaining the time response of Linear systems to either a unit impulse or an arbitrary input from frequency-response data are described and compared. Comparisons indicate that all the methods give good accuracy when applied to a second-order system; the main difference is the required computing time. The methods generally classified as inverse Laplace transform methods were found to be most effective in determining the response to a unit impulse from frequency-… more
Date: March 16, 1956
Creator: Donegan, James J. & Huss, Carl R.
Item Type: Refine your search to only Report
open access

Theoretical calculation of the power spectra of the rolling and yawing moments on a wing in random turbulence

Description: The correlation functions and power spectra of the rolling and yawing moments on an airplane wing due to the three components of continuous random turbulence are calculated. The rolling moments to the longitudinal (horizontal) and normal (vertical) components depend on the spanwise distributions of instantaneous gust intensity, which are taken into account by using the inherent properties of symmetry of isotropic turbulence. The results consist of expressions for correlation functions or spectr… more
Date: September 6, 1956
Creator: Eggleston, John M. & Diederich, Franklin W.
Item Type: Refine your search to only Report
open access

Effect of chord size on weight and cooling characteristics of air-cooled turbine blades

Description: An analysis has been made to determine the effect of chord size on the weight and cooling characteristics of shell-supported, air-cooled gas-turbine blades. In uncooled turbines with solid blades, the general practice has been to design turbines with high aspect ratio (small blade chord) to achieve substantial turbine weight reduction. With air-cooled blades, this study shows that turbine blade weight is affected to a much smaller degree by the size of the blade chord.
Date: November 13, 1956
Creator: Esgar, Jack B.; Schum, Eugene F. & Curren, Arthur N.
Item Type: Refine your search to only Report
open access

Experimental determination of effects of frequency and amplitude on the lateral stability derivatives for a delta, a swept, and unswept wing oscillating in yaw

Description: "Three wing models were oscillated in yaw about their vertical axes to determine the effects of systematic variations of frequency and amplitude of oscillation on the in-phase and out-of-phase combination lateral stability derivatives resulting from this motion. The tests were made at low speeds for a 60 degree delta wing, a 45 degree swept wing, and an unswept wing; the swept and unswept wings had aspect ratios of 4. The results indicate that large changes in the magnitude of the stability der… more
Date: January 6, 1956
Creator: Fisher, Lewis R.
Item Type: Refine your search to only Report
open access

Ditching investigations of dynamic models and effects of design parameters on ditching characteristics

Description: From Summary: "Data from ditching investigations conducted at the Langley Aeronautical Laboratory with dynamic scale models of various airplanes are presented in the form of tables. The effects of design parameters on the ditching characteristics of airplanes, based on scale-model investigations and on reports of full-scale ditchings, are discussed. Various ditching aids are also discussed as a means of improving ditching behavior."
Date: November 16, 1956
Creator: Fisher, Lloyd J. & Hoffman, Edward L.
Item Type: Refine your search to only Report
open access

Measurement of Static Pressure on Aircraft

Description: "Existing data on the errors involved in the measurement of static pressure by means of static-pressure tubes and fuselage vents are presented. The errors associated with the various design features of static-pressure tubes are discussed for the condition of zero angle of attack and for the case where the tube is inclined to flow. Errors which result from variations in the configuration of static-pressure vents are also presented" (p. 645).
Date: December 17, 1956
Creator: Gracey, William
Item Type: Refine your search to only Report
open access

Wind-Tunnel Investigation of a Number of Total-Pressure Tubes at High Angles of Attack -- Subsonic, Transonic, and Supersonic Speeds

Description: "The effect of inclination of the airstream on the measured pressures of 54 total-pressure tubes has been determined for angles of attack up to 60 degrees and over a Mach number range from 0.26 to 1.62. The investigation was conducted in five wind tunnels at the Langley Aeronautical Laboratory" (p. 495).
Date: January 17, 1956
Creator: Gracey, William
Item Type: Refine your search to only Report
open access

The proper combination of lift loadings for least drag on a supersonic wing

Description: From Summary: "Lagrange's method of undetermined multipliers is applied to the problem of properly combining lift loadings for the least drag at a given lift on supersonic wings. The method shows the interference drag between the optimum loading and any loading at the same lift coefficient to be constant. This is an integral form of the criterion established by Robert T. Jones for optimum loadings. The best combination of four loadings on a delta wing with subsonic leading edges is calculated a… more
Date: 1956
Creator: Grant, Frederick C.
Item Type: Refine your search to only Report
open access

Theoretical analysis of total-pressure loss and airflow distribution for tubular turbojet combustors with constant annulus and liner cross-sectional areas

Description: "Compressible and incompressible flow calculations were made of the combustor total-pressure-loss coefficient and liner airflow distribution for tubular turbojet combustors having constant annulus and liner cross-sectional areas along the combustor axis. Information on static and total pressure distribution and liner air-jet entrance angles along the length of the combustor was obtained as an intermediate step in the calculations. The calculations include the effects of heat release, annulus wa… more
Date: September 17, 1956
Creator: Graves, Charles C. & Grobman, Jack S.
Item Type: Refine your search to only Report
open access

Methods for obtaining desired helicopter stability characteristics and procedures for stability predictions

Description: Part I of this report presents a brief review of methods available to the helicopter designer for obtaining desired stability characteristics by modifications to the airframe design. The discussion is based on modifications made during the establishment of flying-qualities criteria and includes sample results of theoretical studies of additional methods. The conclusion is reached that it is now feasible to utilize combinations of methods whereby stability-parameter values are realized which in … more
Date: November 30, 1956
Creator: Gustafson, F. B. & Tapscott, Robert J.
Item Type: Refine your search to only Report
open access

Three-dimensional transonic flow theory applied to slender wings and bodies

Description: The present paper re-examines the derivation of the integral equations for transonic flow around slender wings and bodies of revolution, giving special attention to conditions resulting from the presence of shock waves and to the reduction of the relations to the special forms necessary for the discussion of sonic flow, that is, flow at free-stream Mach number 1.
Date: April 2, 1956
Creator: Heaslet, Max A. & Spreiter, John R.
Item Type: Refine your search to only Report
open access

Induced Velocities Near a Lifting Rotor With Nonuniform Disk Loading

Description: A method is given for converting known uniformly loaded rotor induced velocities to correspond with arbitrary axisymmetric nonuniform disk load distributions. Numerical results for two specific distributions are given in chart form. Symmetry relations and relations between radial disk loading and wake velocities are developed. Experimental flow measurements are presented and compared with theory. Reasonable agreement is shown in the forward part of the flow when nonuniform loading is assumed, b… more
Date: April 1956
Creator: Heyson, Harry H. & Katzoff, S.
Item Type: Refine your search to only Report
open access

Wind-Tunnel and Flight Investigations of the Use of Leading-Edge Area Suction for the Purpose of Increasing the Maximum Lift Coefficient of a 35 Degree Swept-Wing Airplane

Description: "An investigation was undertaken to determine the increase in maximum lift coefficient that could be obtained by applying area suction near the leading edge of a wing. This investigation was performed first with a 35 degree swept-wing model in the wind tunnel, and then with an operational 35 degree swept-wing airplane which was modified in accord with the wind-tunnel results. The wind-tunnel and flight tests indicated that the maximum lift coefficient was increased more than 50 percent by the u… more
Date: 1956
Creator: Holzhauser, Curt A. & Bray, Richard S.
Item Type: Refine your search to only Report
open access

Minimum wave drag for arbitrary arrangements of wings and bodies

Description: "Studies of various arrangements of wings and bodies designed to provide favorable wave interference at supersonic speeds lead to the problem of determining the minimum possible valve of the wave resistance obtainable by any disposition of the elements of an aircraft within a definitely prescribed region. Under the assumptions that the total lift and the total volume of the aircraft are given, conditions that must be satisfied if the drag is to be a minimum are found. The report concludes with … more
Date: February 1956
Creator: Jones, Robert T.
Item Type: Refine your search to only Report
open access

Investigation of the aerodynamic characteristics of a model wing-propeller combination and of the wing and propeller separately at angles of attack up to 90 degrees

Description: This report presents the results of an investigation conducted in the Langley 300 mph 7- by 10-foot wind tunnel for the purpose of determining the aerodynamic characteristics of a model wing-propeller combination, and of the wing and propeller separately at angles of attack up to 90 degrees. The tests covered thrust coefficients corresponding to free-stream velocities from zero forward speed to the normal range of cruising speeds. The results indicate that increasing the thrust coefficient incr… more
Date: 1956
Creator: Kuhn, Richard E. & Draper, John W.
Item Type: Refine your search to only Report
open access

Intensity, scale, and spectra of turbulence in mixing region of free subsonic jet

Description: Report presents the results of the measurements of intensity of turbulence, the longitudinal and lateral correlation coefficients, and the spectra of turbulence in a 3.5-inch-diameter free jet measured with hot-wire anemometers at exit Mach numbers from 0.2 to 0.7 and Reynolds numbers from 192,000 to 725,000.
Date: April 24, 1956
Creator: Laurence, James C.
Item Type: Refine your search to only Report
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