National Advisory Committee for Aeronautics (NACA) - 43 Matching Results

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Preliminary tests to determine the maximum lift of wings at supersonic speeds

Description: Report presenting the results of a test program in a supersonic tunnel to determine the maximum lift of wings operating at supersonic speeds. A variety of wing plan forms of several thickness distributions were tested at a range of Mach numbers, Reynolds numbers, and angles of attack. The lift results, drag results, and Schileren photographs are described.
Date: December 11, 1947
Creator: Gallagher, James J. & Mueller, James N.
Partner: UNT Libraries Government Documents Department

Full-scale investigation of a wing with the leading edge swept back 47.5 degrees and having circular-arc and finite-trailing-edge-thickness ailerons

Description: Report presenting an investigation to determine the aerodynamic characteristics of a wing with a leading sweptback edge at 47.5 degrees and a 20-percent-chord, 50-percent-span outboard aileron. The wing had symmetrical circular-arc airfoil sections and was tested with a circular-arc contour aileron and a flat-sided contour aileron with finite trailing-edge thickness. The longitudinal aerodynamic characteristics and aileron effectiveness are provided for both types of ailerons.
Date: March 11, 1949
Creator: Lange, Roy H.
Partner: UNT Libraries Government Documents Department

Design factors for 4- by 8-inch ram-jet combustor

Description: Report presenting an investigation of a series of flame holders designed with the objective of providing a high combustion efficiency in a ramjet combustor at an inlet air velocity of 200 feet per second, inlet-air pressure of 60 inches of mercury absolute, inlet air temperature of 200 degrees Fahrenheit, and near stoichiometric fuel-air ratio. Results regarding the preliminary experiments, two parallel rows of gutters, three rows of gutters, staggered gutters, simultaneous use of three rows and staggered gutters, use of molybdenum, and magnitude of pressure fluctuations are provided.
Date: August 11, 1949
Creator: Male, Donald W. & Cervenka, Adolph J.
Partner: UNT Libraries Government Documents Department

Comparison of hovering performance of helicopters powered by jet-propulsion and reciprocating engines

Description: Report presenting an investigation of the maximum hovering time, or the time that a helicopter can sustain itself without motion, for helicopters using a reciprocating engine, by ramjet engines at the tips of rotor blades, and by pulse-jet engines at the tips of rotor blades. Testing showed that the reciprocating engine permitted much longer hovering time than the jet-propulsion engines, but the jet-propulsion engines were much lighter and could lift greater disposable loads.
Date: June 11, 1948
Creator: Brightwell, Virginia L.; Peters, Max D. & Sanders, J. C.
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of a flying-boat hull having a length-beam ratio of 15 and a warped forebody

Description: From Introduction: "The results of two phases of this investigation, presented in references 1 and 2, have indicated possible ways of reducing hull drag without causing large changes in aerodynamic stability and hydrodynamic performance."
Date: February 11, 1949
Creator: Macleod, Richard G
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of wing inlets for a four-engine airplane

Description: Report presenting an investigation in the propeller-research tunnel to develop wing-leading-edge inlets for locations between the inboard and outboard nacelles on each wing of a four-engine airplane. Testing was performed on the basic wing and original inlet as well as NACA-developed inlets for two versions of the airplane.
Date: March 11, 1947
Creator: Bartlett, Walter A., Jr. & Goral, Edwin B.
Partner: UNT Libraries Government Documents Department

Altitude-wind-tunnel investigation of thrust augmentation of a turbojet engine 3: performance with tail-pipe burning in standard-size tail pipe

Description: From Introduction: "Evaluation of tail-pipe burning in this engine with a larger tail-pipe combustion chamber is discussed in reference 1. Results of investigations on tail-pipe burning in this engine at static sea-level conditions are presented in reference 2. An investigation of thrust augmentation by means of injecting water at the inlet of an axial-flow compressor engine is discussed in reference 3."
Date: August 11, 1947
Creator: Fleming, William A. & Golladay, Richard L.
Partner: UNT Libraries Government Documents Department

Observations on an aileron-flutter instability encountered on a 45 degree swept-back wing in transonic and supersonic flight

Description: Report presenting a flight test of a supersonic research pilotless aircraft in which large-amplitude aileron oscillations, most likely aileron compressibility flutter, were encountered in the transonic and supersonic speed ranges. Results regarding power-on flight and coasting flight are provided.
Date: April 11, 1947
Creator: Pitkin, Marvin; Gardner, William N. & Curfman, Howard J., Jr.
Partner: UNT Libraries Government Documents Department

A comparison with flight data of vertical-tail loads in various maneuvers estimated from sideslip angles and rudder deflections

Description: Report presenting a comparison of the vertical-tail loads determined from pressure-distribution measurements in flight in various maneuvers with the corresponding vertical-tail loads. Some of the maneuvers investigated included slow rolls, steady sideslips, fishtails, and rolling pull-outs.
Date: December 11, 1947
Creator: Turner, Howard L.
Partner: UNT Libraries Government Documents Department

Free-flight investigation at transonic and supersonic speeds of the rolling effectiveness of several aileron configurations on a tapered wing having 42.7 degrees sweepback

Description: Report presenting an investigation of several aileron modifications in conjunction with a tapered, sweptback wing with circular-arc airfoil sections of relatively large thickness ratio. This testing permits the evaluation of the wing-aileron rolling effectiveness over a range of Mach numbers. Results regarding true-contour ailerons, extended-chord ailerons, and blunt trailing-edge ailerons are provided.
Date: January 11, 1949
Creator: Sandahl, Carl A.
Partner: UNT Libraries Government Documents Department

Langley Full-Scale Tunnel Investigation of a 1/3-Scale Model of the Chance Vought XF5U-1 Airplane

Description: From Summary: "The results of an investigation of a 1/3-scale model of the Chance Vought XF5U-1 airplane in the Langley full-scale tunnel are presented in this report. The maximum lift and stalling characteristics of several model configurations, the longitudinal stability characteristics of the model, and the effectiveness of the control surfaces were determined with the propellers removed. The propulsive characteristics, the effect of propeller operation on the lift, and the static thrust of the model propellers were determined at several propeller-blade angles."
Date: October 11, 1946
Creator: Lange, Roy H.; Cocke, Bennie W., Jr. & Proterra, Anthony J.
Partner: UNT Libraries Government Documents Department

Waters Loads on the XJL-1 Hull as Obtained in Langley Impact Basin, TED No. NACA 2413.3

Description: From Summary: "An investigation was conducted in the Langley impact basin of the water loads on a half scale model of the XJL-1 hull whose forebody has a vee bottom with exaggerated chine flare. The impact loads, moments, and pressures were determined for a range of landing conditions. A normal full-scale landing speed of 86 miles per hour was represented with effective flight paths ranging from 0.6deg to 11.6deg. Landings were made with both fixed trim and free-to-trim mounting of the float over a trim range of -15deg to 12deg into smooth water and into waves having equivalent full-scale length of 120 feet and heights ranging from 1 to 4 feet."
Date: October 11, 1946
Creator: Steiner, Margaret F. & Miller, Robert W.
Partner: UNT Libraries Government Documents Department

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.
Partner: UNT Libraries Government Documents Department

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 square inch to the unrestricted area of the stack of 4.20 square inches. The engine was generally operated over a range of engine speeds from 1300 to 2100 r.p.m, inlet-manifold pressures from 22 to 30 inches of mercury absolute, and a fuel-air ratio of 0.08. The loss in engine power, the jet thrust, and the gain in net thrust are correlated in terms of several simple parameters. An example is given for determining the optimum nozzle area and the overall net thrust.
Date: August 11, 1942
Creator: Pinkel, Benjamin; Turner, L. Richard; Voss, Fred & Humble, Leroy V.
Partner: UNT Libraries Government Documents Department

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.
Partner: UNT Libraries Government Documents Department

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 with constant-speed propellers in which, for given flight conditions, it is desired to determine the propeller revolution speed that gives the maximum ratio of the propulsive efficiency to the specific fuel consumption. The coefficient on which the charts are based may be written in the form of a thrust coefficient or a thrust-power coefficient. A method of using the charts is outlined and sample computations for a typical airplane are included.
Date: December 11, 1940
Creator: Biermann, David & Conway, Robert N.
Partner: UNT Libraries Government Documents Department

Calculation of Wing Bending Moments and Tail Loads Resulting from the Jettison of Wing Tips During a Symmetrical Pull-Up

Description: A preliminary analytical investigation was made to determine the feasibility of the basic idea of controlled failure points as safety valves for the primary airplane structure. The present analysis considers the possibilities of the breakable wing tip which, in failing as a weak link, would relieve the bending moments on the wing structure. The analysis was carried out by computing the time histories of the wing and stabilizer angle of attack in a 10g pull-up for an XF8F airplane with tips fixed and comparing the results with those for the same maneuver, that is, elevator motion but with tips jettisoned at 8g. The calculations indicate that the increased stability accompanying the loss of the wing tips reduces the bending moment an additional amount above that which would be expected from the initial loss in lift and the inboard shift in load. The vortex shed when the tips are lost may induce a transient load requiring that the tail be made stronger than otherwise.
Date: December 11, 1947
Creator: Boshar, John
Partner: UNT Libraries Government Documents Department

Cooling of Gas Turbines I - 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 arising from exposure of the outer blade flange and one face of the rotor to the air. Calculations were next made for the case of fins applied to the outer blade flange and the rotor. Finally the effects of using part of the nozzles (from 0 to 40 percent) for supplying cooling air and the effects of varying the metal thermal conductivity from 12 to 260 Btu per hour per foot per degree Farenheit on the wheel temperatures were determined. The gas temperatures at the nozzle box used in the calculations ranged from 1600F to 2000F. The results showed that if more than a few hundred degrees of cooling of turbine blades are required other means than indirect cooling with fins on the rotor and outer blade flange would be necessary. The amount of cooling indicated for the type of finning used could produce some improvement in efficiency and a large increase in durability of the wheel. The results also showed that if a large difference is to exist between the effective temperature of the exhaust gas and that of the blade material, as must be the case with present turbine materials and the high exhaust-gas temperatures desired (2000F and above), two alternatives are suggested: (a) If metal with a thermal conductivity comparable with copper is used, then the blade temperature can be reduced ...
Date: February 11, 1947
Creator: Brown, Byron
Partner: UNT Libraries Government Documents Department

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-diameter ratio because unknown interference effects existed during the investigation. At a free-stream Mach number of 0.40, the envelopes of the efficiency curves decreased about 11% between advance-diameter ratios of 2.40 and 4.40. An increase in power coefficient from 0.30 to 0.80 at an advance-diameter ratio of 2.40 had little effect on the propeller efficiency. A change in power coefficient from 0.40 to 1.00 at an advance-diameter ratio of 4.40 increased the propeller efficiency by about 40%. For conditions below the stall the thrust loading on the outboard blade sections increased more rapidly than on the inboard sections as the power coefficient was increased or as the advance-diameter ratio was decreased. For conditions beyond the stall, the thrust loading decreased on the outboard sections and increased on the inboard sections.
Date: October 11, 1946
Creator: Saari, Martin J. & Wallner, Lewis E.
Partner: UNT Libraries Government Documents Department

The Effects of Reynolds Number on the Application of NACA 16 Series Airfoil Characteristics to Propeller Design

Description: An analysis has been made of airfoil data taken on several NACA 16-series propeller airfoils from tests of 5-inch-chord models in the Langley 24 inch high-speed tunnel and l2-inch-chord models in the Langley 8 foot high-speed tunnel, This analysis has shown that the combined effects of Reynolds number changes and variations in airfoil characteristics resulting from differences in models and tunnels are such that when 5 inch-chord and l2-inch-chord data are applied to full-scale propeller design at or near the design condition, differences of less than 1 percent in efficiency will be involved.
Date: June 11, 1947
Creator: Cleary, Harold E.
Partner: UNT Libraries Government Documents Department

An Investigation of the Icing and Heated-air De-icing Characteristics of the R-2600-13 Induction System

Description: A laboratory investigation was made on a Holley 1685-HB carburetor mounted on an R-2600-13 supercharger assembly to determine the icing characteristics and the heated-air de-icing requirements of this portion of the B-25D airplane induction system. Icing has been found to be most prevalent at relatively small throttle openings and, consequently, all runs were made at simulated 60-percent normal rated power condition. Icing characteristics were determined during a series of 15-minute runs over a range of inlet-air conditions. For the de-icing investigation severe impact ice was allowed to form in the induction system and the time required for the recovery of 95 percent of the maximum possible air flow at the original throttle setting was then determined for a range of wet-bulb temperatures. Results of these runs showed that ice on the walls of the carburetor adapter and on the rim of the impeller-shroud portion of the supercharger diffuser plate did not affect engine operation at 60-percent normal rated power. Ice that adversely affected the air flow and the fuel-air ratio was formed only on the central web of the carburetor and then only when the inlet air was saturated or contained free moisture in excess of saturation. No serious ice formations were observed at inlet-air temperatures above 66 0 F or with an inlet-air enthalpy greater than 34 Btu per pound. The maximum temperature at. which any trace of icing could be detected was 1110 F with a relative humidity of approximately 28 percent, The air-flow recovery time for emergency de-icing was 0.3 minute enthalpy of 35 Btu per pound or wet-bulb temperature of 68 0 F. Further increase in enthalpy and wet-bulb temperature above these values resulted in very slight improvement in recovery time. The fuel-air ratio restored by a 5-Minute application of heated air was approximately 7 ...
Date: November 11, 1946
Creator: Chapman, Gilbert E.
Partner: UNT Libraries Government Documents Department

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).
Date: February 11, 1947
Creator: Reuter, J. George & Gazley, Carl, Jr.
Partner: UNT Libraries Government Documents Department