National Advisory Committee for Aeronautics (NACA) - 45 Matching Results

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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
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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A theoretical and experimental study of planing surfaces including effects of cross section and plan form

Description: A summary is given of the background and present status of the pure-planing theory for rectangular flat plates and v-bottom surfaces. The equations reviewed are compared with experiment. In order to extend the range of available planing data, the principal planing characteristics for models having sharp bottom surfaces having constant angles of dead rise of 20 degrees and 40 degrees. Planing data were also obtained for flat-plate surfaces with very slightly rounded chines for which decreased li… more
Date: November 23, 1956
Creator: Shuford, Charles L., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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The Similarity Rules for Second-Order Subsonic and Supersonic Flow

Description: "The similarity rules for linearized compressible flow theory (Gothert's rule and its supersonic counterpart) are extended to second order. It is shown that any second-order subsonic flow can be related to "nearly incompressible" flow past the same body, which can be calculated by the Janzen-Rayleigh method" (p. 925).
Date: October 18, 1956
Creator: Van Dyke, Milton D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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Average Properties of Compressible Laminar Boundary Layer on Flat Plate With Unsteady Flight Velocity

Description: The time-average characteristics of boundary layers over a flat plate in nearly quasi-steady flow are determined. The plate may be either insulated or isothermal. The time averages are found without specifying the plate velocity explicitly except that it is positive and has an average value.
Date: September 5, 1956
Creator: Moore, Franklin K. & Ostrach, Simon
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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A low-speed experimental investigation of the effect of a sandpaper type of roughness on boundary-layer transition

Description: From Summary: "An investigation was made in the Langley low-turbulence pressure tunnel to determine the effect of size and location of a sandpaper type of roughness on the Reynolds number for transition. Transition was observed by means of a hot-wire anemometer located at various chordwise stations for each position of the roughness. These observations indicated that when the roughness is sufficiently submerged in the boundary layer to provide a substantially linear variation of boundary-layer … more
Date: August 15, 1956
Creator: von Doenhoff, Albert E. & Horton, Elmer A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Spark ignition of flowing gases

Description: Research conducted at the NACA Lewis Laboratory on ignition of flowing gases by means of long-duration discharges is summarized and analyzed. Data showing the effect of a flowing combustible mixture on the physical and electrical characteristics of spark discharges and data showing the effects of variables on the spark energy required for ignition that has been developed to predict the effect of many of the gas-stream and spark variables is described and applied to a limited amount of experimen… more
Date: June 20, 1956
Creator: Swett, Clyde C., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Torsional Stiffness of Thin-Walled Shells Having Reinforcing Cores and Rectangular, Triangular, or Diamond Cross Section

Description: "A theoretical investigation has been made of the Saint-Venant torsion of certain composite bars. These bars are composed of two materials -- one material in the form of a thin-walled cylindrical shell and the other material in the form of a core which fills the interior of the shell and is bonded to it. An approximate boundary-value problem is formulated on assumptions similar to those of the theory of torsion of hollow thin-walled shells (Bredt theory)" (p. 771).
Date: June 7, 1956
Creator: McComb, Harvey G., Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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A Simplified Method for Approximating the Transient Motion in Angles of Attack and Sideslip During a Constant Rolling Maneuver

Description: "The transient motion in angles of attack and sideslip during a constant rolling maneuver has been analyzed. Simplified expressions are presented for the determination of the pertinent modes of motion as well as the modal coefficient corresponding to each mode. Calculations made with and without the derivatives for side force due to sideslip and lift-curve slope indicate that although these derivatives increase the total damping of the system they do not markedly affect the transient motion" (p… more
Date: May 22, 1956
Creator: Sternfield, Leonard
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A special method for finding body distortions that reduce the wave drag of wing and body combinations at supersonic speeds

Description: For a given wing and supersonic Mach number, the problem of shaping an adjoining fuselage so that the combination will have a low wave drag is considered. Only fuselages that can be simulated by singularities (multipoles) distributed along the body axis are studied. However, the optimum variations of such singularities are completely specified in terms of the given wing geometry. An application is made to an elliptic wing having a biconvex section, a thickness-chord ratio equal to 0.05 at the r… more
Date: May 16, 1956
Creator: Lomax, Harvard & Heaslet, Max A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Propagation of a free flame in a turbulent gas stream

Description: Effective flame speeds of free turbulent flames were measured by photographic, ionization-gap, and photomultiplier-tube methods, and were found to have a statistical distribution attributed to the nature of the turbulent field. The effective turbulent flame speeds for the free flame were less than those previously measured for flames stabilized on nozzle burners, Bunsen burners, and bluff bodies. The statistical spread of the effective turbulent flame speeds was markedly wider in the lean and r… more
Date: May 7, 1956
Creator: Mickelsen, William R. & Ernstein, Norman E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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An evaluation of four experimental methods for measuring mean properties of a supersonic turbulent boundary layer

Description: From Summary: "Surveys were made through a turbulent boundary layer on a flat plate by means of a pitot probe, an x-ray densitometer, and hot-wire and cold-wire probes. Results from these surveys were analyzed to determine (a) the reliability of the basic data and hence the methods by which they were obtained, and (b) how well the actual distributions of properties in the boundary layer compare with those commonly assumed in semiempirical and theoretical analyses. All surveys were made at the s… more
Date: April 19, 1956
Creator: Nothwang, George J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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