National Advisory Committee for Aeronautics (NACA) - 46 Matching Results

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Effects of wing flexibility and variable air lift upon wing bending moment during landing impacts of a small seaplane

Description: From Summary: "A smooth-water-landing investigation was conducted with a small seaplane to obtain experimental wing-bending-moment time histories together with time histories of the various parameters necessary for the prediction of wing bending moments during hydrodynamic forcing functions. The experimental results were compared with calculated results which include inertia-load effects and the effects of air-load variation during impact. The responses of the fundamental mode were calculated with the use of the measured hydrodynamic forcing functions. From these responses, the wing bending moments due to the hydrodynamic load were calculated according to the procedure given in R.M. No. 2221. The comparison of the time histories of the experimental and calculated wing bending moments showed good agreement both in phase relationship of the oscillations and in numerical values."
Date: December 21, 1949
Creator: Merten, Kenneth F. & Beck, Edgar B.
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of a wing with unswept quarter-chord line, aspect ratio 4, taper ratio 0.6, and NACA 65A006 airfoil section

Description: From Introduction: "This paper presents the results of the investigation of the wing-alone and of the wing-fuselage configuration employing a wing with an unswept quarter-chord line, aspect ratio 4, taper ratio 0.6, and an NACA 65A006 airfoil section parallel to the air stream. The results of closely related sweptback-wing investigations, which are part of the present transonic programs, are presented in references 1 to 3."
Date: October 21, 1949
Creator: Goodson, Kenneth W. & Morrison, William D., Jr.
Partner: UNT Libraries Government Documents Department

General Characteristics of a Airspeed System using Fuselage Static Vents on a Swept-Wing Airplane

Description: Studies have been made by the NACA wing-flow method of the use of fuselage static orifices between the wing and tail of a swept-wing airplane for possible application to service airspeed installations. The tests were made at zero angle of attack. The results indicate that, although the maximum errors are large, these locations are usable from the consideration that the local Mach numbers at the locations studied are sensitive to variation of the true Mach number within the test Mach number range of 0.7 to 1.2. The maximum errors in Mach number in the subsonic range varied from zero for the most forward location to -0.05 for the most rearward location (indicated Mach number less than true). At Mach numbers above 1.0, the maximum errors were from 0.14 for the most forward location to 0.04 for the most rearward location.
Date: October 21, 1949
Creator: Johnston, J. Ford & OBryan, Thomas C.
Partner: UNT Libraries Government Documents Department

The effect of span and deflection of split flaps and leading-edge roughness on the longitudinal stability and gliding characteristics of a 42 degree sweptback wing equipped with leading-edge flaps

Description: Report discussing the effect of half-span and full-span split flaps through a deflection range on the low-speed, longitudinal characteristics of a sweptback wing with a round-nose, extensible leading-edge flap. Information about the effect of split-flap deflection on lift and stalling characteristics, effect of split flaps on gliding characteristics, and effect of leading-edge roughness on longitudinal stability is presented.
Date: June 21, 1949
Creator: Pratt, George L. & Bollech, Thomas V.
Partner: UNT Libraries Government Documents Department

Two-dimensional compressible flow in centrifugal compressors with straight blades

Description: "Six numerical examples are presented for steady, two-dimensional, compressible, nonviscous flow in centrifugal compressors with thin straight blades, the center lines of which generate the surface of a right circular cone when rotated about the axis of the compressor. A seventh example is presented for incompressible flow. The solutions were obtained in a region of the compressors, including the impeller tip, that was considered to be unaffected by the diffuser vanes or by the impeller-inlet configuration" (p. 141).
Date: June 21, 1949
Creator: Stanitz, John D. & Ellis, Gaylord O.
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of a wing with quarter-chord line swept back 35 degrees, aspect ratio 4, taper ratio 0.6, and NACA 65A006 airfoil section: Transonic-bump method

Description: From Introduction: "This paper presents the results of the investigation of wing-alone and wing-fuselage combinations employing a wing with the quarter-chord line swept back 35^o, aspect ratio 4, taper ratio 0.6, and NACA 65A006 airfoil section."
Date: April 21, 1949
Creator: Sleeman, William C., Jr. & Becht, Robert E.
Partner: UNT Libraries Government Documents Department

On Stability of Free Laminar Boundary Layer Between Parallel Streams

Description: "An analysis and calculations on the stability of the free laminar boundary layer between parallel streams were made for an incompressible fluid using the Tollmien-Schlichting theory of small disturbances. Because the boundary conditions are at infinity, two solutions of the Orr-Sommerfeld stability equations need not be considered, and the remaining two solutions are exponential in character at the infinite boundaries. The calculations show that the flow is unstable except for very low Reynolds numbers" (p. 571).
Date: March 21, 1949
Creator: Lessen, Martin
Partner: UNT Libraries Government Documents Department

Investigation with an interferometer of the turbulent mixing of a free supersonic jet

Description: The free turbulent mixing of a supersonic jet of Mach number 1.6 has been experimentally investigated. An interferometer, of which a description is given, was used for the investigation. Density and velocity distributions through the mixing zone have been obtained. It was found that there was similarity in distribution at the cross sections investigated and that, in the subsonic portion of the mixing zone, the velocity distribution fitted the theoretical distribution for incompressible flow. It was found that the rates of spread of the mixing zone both into the jet and into the ambient air were less than those of subsonic jets.
Date: January 21, 1949
Creator: Gooderum, Paul B.; Wood, George P. & Brevoort, Maurice J.
Partner: UNT Libraries Government Documents Department

Performance of 24-inch supersonic axial-flow compressor in air 2: performance of compressor rotor at equivalent tip speeds from 800 to 1765 feet per second

Description: Report presenting an investigation of a 24-inch-diameter rotor for a supersonic axial-flow compressor in air up to an actual tip speed of 1654 feet per second and a maximum equivalent tip speed of 1765 feet per second. Results regarding overall performance, rotor-inlet characteristics, rotor-passage flow characteristics, and rotor-outlet characteristics are provided.
Date: January 21, 1949
Creator: Johnsen, Irving A.; Wright, Linwood C. & Hartmann, Melvin J.
Partner: UNT Libraries Government Documents Department

Response of a Rotating Propeller to Aerodynamic Excitation

Description: The flexural vibration of a rotating propeller blade with clamped shank is analyzed with the object of presenting, in matrix form, equations for the elastic bending moments in forced vibration resulting from aerodynamic forces applied at a fixed multiple of rotational speed. Matrix equations are also derived which define the critical speeds end mode shapes for any excitation order and the relation between critical speed and blade angle. Reference is given to standard works on the numerical solution of matrix equations of the forms derived. The use of a segmented blade as an approximation to a continuous blade provides a simple means for obtaining the matrix solution from the integral equation of equilibrium, so that, in the numerical application of the method presented, the several matrix arrays of the basic physical characteristics of the propeller blade are of simple form, end their simplicity is preserved until, with the solution in sight, numerical manipulations well-known in matrix algebra yield the desired critical speeds and mode shapes frame which the vibration at any operating condition may be synthesized. A close correspondence between the familiar Stodola method and the matrix method is pointed out, indicating that any features of novelty are characteristic not of the analytical procedure but only of the abbreviation, condensation, and efficient organization of the numerical procedure made possible by the use of classical matrix theory.
Date: January 21, 1949
Creator: Arnoldi, Walter E.
Partner: UNT Libraries Government Documents Department

Hydrodynamic Characteristics of a Low-Drag, Planing-Tail Flying-Boat Hull

Description: Report discussing the hydrodynamic characteristics of a flying boat with a low-drag, planing-tail hull compared with a conventional-type hull. The planing-tail model had more take-off stability than the conventional model and had lower hydrodynamic resistance. Information about the landing stability, variation of trim with speed, and spray characteristics is also provided.
Date: October 21, 1948
Creator: Suydam, Henry B.
Partner: UNT Libraries Government Documents Department

Hydrodynamic characteristics of a low-drag, planing-tail flying-boat hull

Description: From Summary: "The hydrodynamic characteristics of a flying-boat incorporating a low-drag, planing-tail hull were determined from model tests made in Langley tank number 2 and compared with tests of the same flying boat incorporating a conventional-type hull. The planing-tail model, with which stable take-offs were possible for a large range of elevator positions at all center-of-gravity locations tested, had more take-off stability than the conventional model."
Date: October 21, 1948
Creator: Suydam, Henry B.
Partner: UNT Libraries Government Documents Department

Tests of a triangular wing of aspect ratio 2 in the Ames 12-foot pressure wind tunnel 2: the effectiveness and hinge moments of a constant-chord plain flap

Description: Report presenting a semispan triangular wing with a constant-chord trailing-edge flap to evaluate the aerodynamic characteristics of the wing with landing speeds up to a Mach number of 0.95. Tests were included to ascertain the effects of the addition of a body and of modifications to the airfoil section. Results regarding the wing alone with low Mach number, wing alone with high Mach number, effect of the body, effect of the flap, effect of Mach number, lift-drag ratio, and wing-profile modifications are provided.
Date: September 21, 1948
Creator: Stephenson, Jack D. & Amuedo, Arthur R.
Partner: UNT Libraries Government Documents Department

Tests of a triangular wing of aspect ratio 2 in the Ames 12-foot pressure wind tunnel III : the effectiveness and hinge moments of a skewed wing-tip flap

Description: Results of wind-tunnel tests of a semispan model of a triangular wing of aspect ratio 2 with a skewed wing-tip flap are presented. Lift, drag, pitching-moment, and hinge-moment data are included for subsonic Mach numbers up to 0.95. The flap showed extremely high hinge moments and low effectiveness as a longitudinal control. Although less affected by compressibility, this flap is indicated to be inferior to a constant-chord flap when applied to this triangular wing.
Date: September 21, 1948
Creator: Kolbe, Carl D. & Tinling, Bruce E.
Partner: UNT Libraries Government Documents Department

Effect of a nacelle on the low-speed aerodynamic characteristics of a swept-back wing

Description: Wind-tunnel tests of a simplified nacelle on a semispan wing having approximately 35 degrees of sweepback were made at low speeds to evaluate the effects of the nacelle on the aerodynamic characteristics of the wing. Force, moment, and pressure-distribution measurements are presented for the nacelle underslung and centrally mounted on the wing and mounted on a strut below the wing.
Date: July 21, 1948
Creator: Hanson, Frederick H., Jr. & Dannenberg, Robert E.
Partner: UNT Libraries Government Documents Department

Free-flight investigation at transonic and supersonic speeds of a wing-aileron configuration simulating the D-558-2 airplane

Description: From Summary: "An investigation of the rolling effectiveness at transonic and supersonic speeds of a wing-aileron configuration simulating the D-558-2 airplane has been made by means of a rocket-propelled test vehicle. The variation of rolling effectiveness with Mach number is similar to that obtained previously for tapered sweptback wings having full-span, 0.2-chord ailerons."
Date: July 21, 1948
Creator: Sandahl, Carl A.
Partner: UNT Libraries Government Documents Department

An investigation at low speed of a 51.3 degrees sweptback semispan wing with a raked tip and with 16.7-percent-chord ailerons having three spans and three trailing-edge angles

Description: Report presenting a wind-tunnel investigation at low speed to determine the aerodynamic characteristics of a 51.3 degree sweptback semispan wing with a raked tip and with 16.7-percent-chord sealed plain ailerons. Lift, drag, pitching-moment, and hinge-moment data were obtained for the wing with transition free and fixed with various spans of aileron deflected as lift flaps. The rolling moment, yawing moment, hinge moment, and aileron seal pressure characteristics were determined for each of the nine possible aileron-span and trailing-edge-angle combinations tested.
Date: July 21, 1948
Creator: Fischel, Jack & Schneiter, Leslie E.
Partner: UNT Libraries Government Documents Department

Measurement through the speed of sound of static pressures on the rear of unswept and sweptback circular cylinders and on the rear and sides of a wedge by the NACA wing-flow method

Description: Report presenting static-pressure measurements made through the speed of sound by the NACA wing-flow method at the back of two unswept circular cylinders and one sweptback cylinder. Static pressures were found to decrease considerably with an increase in Mach number. Information about the length and diameter of the cylinders and how it affects measurements is provided.
Date: July 21, 1948
Creator: Sawyer, Richard H. & Daum, Fred L.
Partner: UNT Libraries Government Documents Department

Study of stress states in gas-turbine disk as determined from measured operating-temperature distributions

Description: Report presenting results of an experimental investigation to determine the temperature distribution in an aircraft-engine gas-turbine disk. Calculated stresses based on the measured temperature distributions are presented. Results regarding stresses in the inner region of the disk and stresses in the rim of the disk are provided.
Date: July 21, 1948
Creator: Farmer, J. Elmo; Millenson, M. B. & Manson, S. S.
Partner: UNT Libraries Government Documents Department

Equations for the Design of Two-Dimensional Supersonic Nozzles

Description: Memorandum presenting equations for obtaining the wall coordinates of two-dimensional supersonic nozzles. The equations are based on the application of the method of characteristics to irrotational flow of perfect gases in channels. A brief discussion of characteristics as applied to nozzle design is given to assist in understanding and applying the nozzle-design method of the report.
Date: June 21, 1948
Creator: Pinkel, I. Irving
Partner: UNT Libraries Government Documents Department

Investigation of wing characteristics at a Mach number of 1.53 3: unswept wings of differing aspect ratio and taper ratio

Description: Report presenting testing of seven models that from two different wing series: a series of taper ratio 0.5 and differing aspect ratio and a series of aspect ratio 4 and differing taper ratio. Measurements of lift, drag, and pitching moment were made at Mach number 1.53. The aerodynamic parameters generally varied with aspect ratio and taper ratio in the manner indicated by the linear theory.
Date: June 21, 1948
Creator: Nielsen, Jack N.; Matteson, Frederick H. & Vincenti, Walter G.
Partner: UNT Libraries Government Documents Department

NACA: University Conference on Aerodynamics, A Compilation of the Papers Presented

Description: This document contains reproductions of the technical papers presented at the NACA - University Conference on Aerodynamics held at the Langley Aeronautical Laboratory on June 21, 22, and 23, 1948. The conference was held in recognition of the difficulties, imposed by security restrictions, in keeping abreast of the rapid advances in aerodynamics. The papers were prepared to review the status of a number of fields of interest, to summarize the more important wartime advances that are no longer classified, and to orient reference material for further study. The papers in this document are in the same form in which they were presented at the conference so that distribution of them might be prompt. The original presentation and this record are considered as complementary to, rather than as substitutes for, the Committee?s system of complete and formal reports.
Date: 1948-06-21/1948-06-23
Partner: UNT Libraries Government Documents Department