Search Results

open access

Properties of low-aspect-ratio pointed wings at speeds below and above the speed of sound

Description: "Low-aspect-ratio wings having pointed plan forms are treated on the assumption that the flow potentials in planes at right angles to the long axis of the airfoils are similar to the corresponding two-dimensional potentials. For the limiting case of small angles of attack and low aspect ratios the theory brings out the following significant properties: (1) The lift of a slender, pointed airfoil moving in the direction of its long axis depends on the increase in width of the sections in a downst… more
Date: May 11, 1945
Creator: Jones, Robert T.
open access

Aerodynamic study of a wing-fuselage combination employing a wing swept back 63 degrees: Subsonic Mach and Reynolds number effects on the characteristics of the wing and on the effectiveness of an elevon

Description: Report presenting a wind-tunnel investigation of a semispan model of a wing swept back 63 degrees with an aspect ratio of 3.5 and a taper ratio of 0.25. The tests were conducted to evaluate the effects of Reynolds and Mach number on the aerodynamic characteristics of the wing. Results regarding the characteristics of the wing with the elevon undeflected, effectiveness of the elevon, effects of roughness strips, and effect of model deflection under varying loads are provided.
Date: October 11, 1948
Creator: Reynolds, Robert M. & Smith, Donald W.
open access

An Investigation of the Downwash Behind a High-Aspect-Ratio Wing With Various Amounts of Sweep in the Langley 8-Foot High-Speed Tunnel

Description: Report presenting measurements of downwash angles at points at two vertical positions at the probable tail location behind a high-aspect-ratio wing with an NACA 65-210 section with no sweep and 30 degrees and 45 degrees of sweepback and sweepforward in conjunction with a fuselage.
Date: May 11, 1948
Creator: Whitcomb, Richard T.
open access

Langley Free-Flight-Tunnel Investigation of the Automatic Lateral Stability Characteristics of a Model Equipped with a Gyro Stabilizing Unit that Provided either Flicker-Type or Hunting Control

Description: Memorandum presenting an investigation to determine the automatic lateral stability characteristics of a model equipped with a gyro stabilizing unit that gave response to bank and yaw. Stable flights were obtained with the flicker-type automatic control, and the amplitude of the oscillations was decreased by adding the attachment which provided hunting control.
Date: January 11, 1949
Creator: Schade, Robert O.
open access

Flight Tests of a Two-Dimensional Wedge Diffuser at Transonic and Supersonic Speeds

Description: "A two-dimensional wedge diffuser, designed to be used with a ducted-airfoil ram jet, was tested on a rocket-powered test vehicle up to a Mach number of 1.45. Orifice plates and a choking section behind the diffuser exit simulated burning in a combustion chamber by providing the proper pressure drop. Results obtained from these tests showed there was no abrupt changes in mass flow and pressure recovery as the model velocity increased through the transonic region" (p. 1).
Date: August 11, 1948
Creator: Faget, M. A.
open access

Free-spinning wind-tunnel tests of a low-wing monoplane with systematic changes in wings and tails V: effect of airplane relative density

Description: The reported tests are a continuation of an NACA investigation being made in the free-spinning wind tunnel to determine the effects of independent variations in load distribution, wing and tail arrangement, and control disposition on the spin characteristics of airplanes. The standard series of tests was repeated to determine the effect of airplane relative density. Tests were made at values of the relative-density parameter of 6.8, 8.4 (basic), and 12.0; and the results were analyzed. The test… more
Date: January 11, 1940
Creator: Seidman, Oscar & Neihouse, A. I.
open access

Investigation of Pressure Losses in Several Turbosupercharger Nozzle Hoses

Description: Memorandum presenting surveys of the impact pressure of the flow to obtain information for determining pressure losses in four different turbosupercharger nozzle boxes. The data indicated substantial differences in total head loss among the boxes and the existence of sharply defined high-loss regions in portions of the nozzle annulus.
Date: February 11, 1947
Creator: Lord, Albert M. & Donnola, Joseph
open access

Propeller charts for the determination of the rotational speed for the maximum ratio of the propulsive efficiency to the specific fuel consumption

Description: A set of propeller operating efficiency charts, based on a coefficient from which the propeller rotational speed has been eliminated, is presented. These charts were prepared with data obtained from tests of full-size metal propellers in the NACA propeller-research tunnel. Working charts for nine propeller-body combinations are presented, including results from tests of dual-rotating propellers. These charts are to be used in the calculation of the range and the endurance of airplanes equipped … more
Date: December 11, 1940
Creator: Biermann, David & Conway, Robert N.
open access

Preknock vibrations in a spark-ignition engine cylinder as revealed by high-speed photography

Description: "The high-speed photographic investigation of the mechanics of spark-ignition engine knock recorded in three previous reports has been extended with use of the NACA high-speed camera and combustion apparatus with a piezoelectric pressure pickup in the combustion chamber. The motion pictures of knocking combustion were taken at the rate of 40,000 frames per second. Existence of the preknock vibrations in the engine cylinder suggested in Technical Report no.727 has been definitely proved and the … more
Date: September 11, 1944
Creator: Miller, Cearcy D. & Logan, Walter O., Jr.
open access

Summary of Drag Characteristics of Practical-Construction Wing Sections

Description: "The effect of several parameters on the drag characteristics of practical-construction wing sections have been considered and evaluated. The effects considered were those of surface roughness, surface waviness, compressive load, and de-icers. The data were obtained from a number of tests in the Langley two-dimensional low-turbulence tunnels" (p. 359).
Date: July 11, 1946
Creator: Quinn, John H., Jr.
open access

Exhaust-stack nozzle area and shape for individual cylinder exhaust-gas jet-propulsion system

Description: This report presents the results of an investigation conducted on the effect of exhaust-stack nozzle area, shape, and length on engine power, jet thrust, and gain in net thrust (engine propeller plus jet). Single-cylinder engine data were obtained using three straight stacks 25, 44, and 108 inches in length; an S-shaped stack, a 90 degree bend, a 180 degree bend, and a short straight stack having a closed branch faired into it. Each stack was fitted with nozzles varying in exit area from 0.91 s… more
Date: August 11, 1942
Creator: Pinkel, Benjamin; Turner, L. Richard; Voss, Fred & Humble, Leroy V.
open access

Propellers in yaw

Description: It was realized as early as 1909 that a propeller in yaw develops a side force like that of a fin. In 1917, R. G. Harris expressed this force in terms of the torque coefficient for the unyawed propeller. Of several attempts to express the side force directly in terms of the shape of the blades, however, none has been completely satisfactory. An analysis that incorporates induction effects not adequately covered in previous work and that gives good agreement with experiment over a wide range of … more
Date: October 11, 1943
Creator: Ribner, Herbert S.
open access

Wind-tunnel investigation of air inlet and outlet openings on a streamline body

Description: In connection with the general problem of providing air flow to an aircraft power plant located within a fuselage, an investigation was conducted in the Langley 8-foot high-speed tunnel to determine the effect on external drag and pressure distribution of air inlet openings located at the nose of a streamline body. Air outlet openings located at the tail and at the 21-percent and 63-percent stations of the body were also investigated. Boundary layer transition measurements were made and correla… more
Date: September 11, 1940
Creator: Becker, John V.
open access

Comparison of wind-tunnel and flight measurements of stability and control characteristics of a Douglas A-26 airplane

Description: From Summary: "Stability and control characteristics determined from tests in the Langley 19-foot pressure tunnel of a 0.2375-scale model of the Douglas XA-26 airplane are compared with those measured in flight tests of a Douglas A-26 airplane. Agreement regarding static longitudinal stability as indicated by the elevator-fixed neutral points and by the variation of elevator deflection in both straight and turning flight was found to be good except at speeds approaching the stall. At these low … more
Date: August 11, 1945
Creator: Kayten, Gerald G. & Koven, William
open access

An analysis of available data on effects of wing-fuselage-tail and wing-nacelle interference on the distribution of the air load among components of airplanes

Description: From Introduction: "The purpose of the present paper is to summarize the available data on the effects of wing-fuselage-tail and wing-nacelle interference on the distribution of the air load among aircraft components. Some discussion is also given of the effects of center-of-gravity position."
Date: April 11, 1949
Creator: Wollner, Bertram C.
open access

Performance of J33-A-27 Turbojet-Engine Compressor 1: Over-all performance characteristics at equivalent impeller speeds from 6100 to 11,800 rpm

Description: The J33-A-27 compressor was operated at an inlet pressure of 14 inches of mercury absolute and ambient inlet temperature over a range of equivalent impeller speeds from 6100 to 11,800 rpm. At the design equivalent speed of 11,800 rpm, the J33-A-27 compressor had a peak pressure ratio of 4.40 at an equivalent weight flow of 105.7 pounds per second and a peak adiabatic temperature-rise efficiency of 0.745. The maximum equivalent weight flow at design speed was 113.5 pounds per second.
Date: July 11, 1949
Creator: Kovach, Karl & Osborn, Walter M.
open access

Results of Flight Test of an Automatically Stabilized Model C (Swept Back) Four-Wing Tiamat

Description: "The results of the first flight test of a swept-back four-wing version of Tiamat (MX-570 model C) which was launched at the NACA Pilotless Aircraft Research Station at W4110PB Island, Va. are presented. In general, the flight behavior was close to that predicted by calculations based an stability theory and oscillating table tests of the autopilot. The flight test thus indicates that the techniques employed to predict automatic stability are valid and practical from an operational viewpoint" (… more
Date: June 11, 1947
Creator: Seacord, Charles L., Jr. & Teitelbaum, J. M.
open access

Tests of a Horizontal-Tail Model through the Transonic Speed Range by the NACA Wing-Flow Method

Description: "A 1/12-scale model of a horizontal tail of a fighter airplane was tested through the transonic speeds in the high-speed flow over an airplane wing, the surface of which served as a reflection plane for the model. Measurements of lift, elevator-hinge moment, angle of attack, and elevator angle were made in the Mach number range from 0.75 to 1.04 for elevator deflections ranging from 10 degrees to minus 10 degrees, and for angles of attack of minus 1.2 degrees, 0.4 degrees, and 3.4 degrees. The … more
Date: April 11, 1947
Creator: Adams, Richard E. & Silsby, Norman S.
open access

Cooling of Gas Turbines 1 - Effects of Addition of Fins to Blade Tips and Rotor, Admission of Cooling Air Through Part of Nozzles, and Change in Thermal Conductivity of Turbine Components

Description: "An analysis was developed for calculating the radial temperature distribution in a gas turbine with only the temperatures of the gas and the cooling air and the surface heat-transfer coefficient known. This analysis was applied to determine the temperatures of a complete wheel of a conventional single-stage impulse exhaust-gas turbine. The temperatures were first calculated for the case of the turbine operating at design conditions of speed, gas flow, etc. and with only the customary cooling a… more
Date: February 11, 1947
Creator: Brown, W. Byron
open access

Altitude-Wind-Tunnel Investigation of Performance of Several Propellers on YP-47M Airplane at High Blade Loading, 1, Aeroproducts H20C-162-X11M2 Four-Blade Propeller

Description: "An investigation was made in the Cleveland Altitude wind tunnel to determine the performance of an Aeroproducts H20C-162-X11M2 four-blade propeller on a YP-47M airplane at high blade loadings and high engine powers. The propeller characteristics were obtained for a range of power coefficients from 0.30 to 1.00 at free-stream Mach numbers of 0.40 and 0.50. The results of the force measurements are indicative only of trends in propeller efficiency with changes in power coefficient and advance-di… more
Date: October 11, 1946
Creator: Saari, Martin J. & Wallner, Lewis E.
open access

Cooling of Gas Turbines, 3, Analysis of Rotor and Blade Temperatures in Liquid-Cooled Gas Turbines

Description: A theoretical analysis of the radial temperature distribution through the rotor and constant cross sectional area blades near the coolant passages of liquid cooled gas turbines was made. The analysis was applied to obtain the rotor and blade temperatures of a specific turbine using a gas flow of 55 pounds per second, a coolant flow of 6.42 pounds per second, and an average coolant temperature of 200 degrees F. The effect of using kerosene, water, and ethylene glycol was determined. The effect … more
Date: February 11, 1947
Creator: Brown, W. Byron & Livingood, John N. B.
open access

Computed Temperature Distribution and Cooling of Solid Gas-Turbine Blades

Description: "Computations were made to determine the temperature distribution and cooling of solid gas-turbine blades.A range of temperatures was used from 1500 degrees to 2500 degrees F, blade-root temperatures from 100 degrees to 1000 degrees F, blade thermal conductivity from 8 to 220 BTU/(hr)(sq ft)(degrees F/ft), and net gas to metal heat transfer coefficients from 75 to 250 BTU/(hr)(sq ft)(degrees F)" (p. 1).
Date: February 11, 1947
Creator: Reuter, J. George & Gazley, Carl, Jr.
open access

Theoretical Evaluation of Methods of Cooling the Blades of Gas Turbines

Description: A study was made of heat transfer in turbine blades and the effects on blade temperature of cooling the blade root and tip, changing the dimensions of the blades, raising the cycle temperatures, insulating with ceramics, and cooling by circulation of air or water through hollow blades. The results indicated that cooling of the root of the blade, shortening the blade, and cooling hollow blades internally with air or liquid offer possibilities of substantial increases in permissible gas temperatu… more
Date: February 11, 1947
Creator: Sanders, J. C. & Mendelson, Alexander
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