National Advisory Committee for Aeronautics (NACA) - 41 Matching Results

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The problem of cooling an air-cooled cylinder on an aircraft engine

Description: An analysis of the cooling problem has been to show by what means the cooling of an air-cooled aircraft engine may be improved. Each means of improving cooling is analyzed on the basis of effectiveness in cooling with respect to power for cooling. The altitude problem is analyzed for both supercharged and unsupercharged engines. The case of ground cooling is also discussed. The heat-transfer process from the hot gases to the cylinder wall is discussed on the basis of the fundamentals of heat transfer and thermodynamics. Adiabatic air-temperature rise at a stagnation point in compressible flow is shown to depend only on the velocity of flow.
Date: April 22, 1940
Creator: Brevoort, M. J. & Joyner, U. T.
Partner: UNT Libraries Government Documents Department

Methods of analyzing wind-tunnel data for dynamic flight conditions

Description: The effects of power on the stability and the control characteristics of an airplane are discussed and methods of analysis are given for evaluating certain dynamic characteristics of the airplane that are not directly discernible from wind tunnel tests alone. Data are presented to show how the characteristics of a model tested in a wind tunnel are affected by power. The response of an airplane to a rolling and a yawing disturbance is discussed, particularly in regard to changes in wing dihedral and fin area. Solutions of the lateral equations of motion are given in a form suitable for direct computations. An approximate formula is developed that permits the rapid estimation of the accelerations produced during pull-up maneuvers involving abrupt elevator deflections.
Date: July 22, 1941
Creator: Donlan, C. J. & Recant, I. G.
Partner: UNT Libraries Government Documents Department

Investigation of the NACA 4-(3)(8)-045 Two-Blade Propellers at Forward Mach Numbers to 0.725 to Determine the Effects of Compressibility and Solidity on Performance

Description: From Summary: "As part of a general investigation of propellers at high forward speeds, tests of two 2-blade propellers having the NACA 4-(3)(8)-03 and NACA 4-(3)(8)-45 blade designs have been made in the Langley 8-foot high-speed tunnel through a range of blade angle from 20 degrees to 60 degrees for forward Mach numbers from 0.165 to 0.725 to establish in detail the changes in propeller characteristics due to compressibility effects. These propellers differed primarily only in blade solidity, one propeller having 50 percent and more solidity than the other. Serious losses in propeller efficiency were found as the propeller tip Mach number exceeded 0.91, irrespective of forward speed or blade angle."
Date: January 22, 1944
Creator: Stack, John; Draley, Eugene C.; Delano, James B. & Feldman, Lewis
Partner: UNT Libraries Government Documents Department

Drag Measurements at Transonic Speeds of NACA 65-009 Airfoils Mounted on a Freely Falling Body to Determine the Effects of Sweepback and Aspect Ratio

Description: From Summary: "Drag measurements at transonic speeds on rectangular airfoils and on airfoils swept back 450 are reported. These airfoils, which were mounted on cylindrical test bodies, are part of a series being tested in free drops from high altitude to determine the effect of variation of basic airfoil parameters on airfoil drag characteristics at transonic speeds. These rectangular and swept-back airfoils had the same span, airfoil section (NACA 65-009), and chord perpendicular to the leading edge. The tests were made to compare the drag of rectangular and sweptback airfoils at a higher aspect ratio than had been used in a similar comparison reported previously."
Date: January 22, 1947
Creator: Mathews, Charles W. & Thompson, Jim Rogers
Partner: UNT Libraries Government Documents Department

Correlation of the Trim Limits of Stability Obtained for a PB2Y-3 Flying Boat and a 1/8-Size Powered Dynamic Model

Description: Tests of a PB2Y-3 flying boat were made at the U.S. Naval Air Station, Patuxent River, Md., to determine its hydrodynamic trim limits of stability. Corresponding tests were also made of a 1/8-size powered dynamic model of the same flying boat in Langley tank no. 1. During the tank tests, the full-size testing procedure was reproduced as closely as possible in order to obtain data for a direct correlation of the results. As a nominal gross load of 66,000 pounds, the lower trim limits of the full-size and model were in good agreement above a speed of 80 feet per second. As the speed decreased below 80 feet per second, the difference between the model trim limits and full-scale trim limits gradually became larger. The upper trim limit of the model with flaps deflected 0 deg was higher than that of the full-size, but the difference was small over the speed range compared. At flap deflections greater than 0 deg, it was not possible to trim either the model of the airplane to the upper limit with the center of gravity at 28 percent of the mean aerodynamic chord. The decrease in the lower trim limits with increase in flap deflection showed good agreement for the airplane and model. The lower trim limits obtained at different gross loads for the full-size airplane were reduced to approximately a single curve by plotting trim against the square root of C(sub delta (sub o)) divided by C(sub V).
Date: April 22, 1947
Creator: Garrison, Charlie C.; Goldenbaum, David M. & Hacskaylo, Andrew
Partner: UNT Libraries Government Documents Department

Drag characteristics of rectangular and swept-back NACA 65-009 airfoils having various aspect ratios as determined by flight tests at supersonic speeds

Description: Report presenting tests to determine the effect of sweepback angle and aspect ratio on the drag at supersonic speeds of wings of NACA 65-009 airfoil section. The current report is part of a bigger investigation and includes results for aspect ratios of 3.8 and 5.0. Results regarding the drag coefficient and general effect of aspect ratio are provided.
Date: April 22, 1947
Creator: Tucker, Warren A. & Nelson, Robert L.
Partner: UNT Libraries Government Documents Department

An investigation of the downwash at the probable tail location behind a high-aspect-ratio wing in the Langley 8-foot high-speed tunnel

Description: Report presenting measurements downwash angles behind a model of a high-aspect-ratio wing at points near the probable tail location at Mach numbers up to 0.89 in the high-speed tunnel. The model has an NACA 65-210 section, an aspect ratio of 9.0, a taper ratio of 2.5:1, no twist, dihedral, or sweepback. Results regarding experimental data and comparison of experimental and calculated results are provided.
Date: April 22, 1947
Creator: Whitcomb, Richard T.
Partner: UNT Libraries Government Documents Department

An Investigation of the Aerodynamic Characteristics of an 0.08-Scale Model of the Chance Vought XF7U-1 Airplane in the Langley High-Speed 7- by 10-Foot Tunnel. Part IV - Aileron Characteristics TED No. NACA DE308, Part 4, Aileron Characteristics, TED No. NACA DE308

Description: Tests have been conducted in the Langley high-speed 7- by 10-foot tunnel over a Mach number range from 0.40 to 0.91 to determine the stability and control characteristics of an 0.08-scale model of the Chance Vought XF7U-1 airplane. The aileron characteristics of the complete model are presented in the present report with a very limited analysis of the results.
Date: August 22, 1947
Creator: Goodson, Kenneth W. & Myers, Boyd C., II
Partner: UNT Libraries Government Documents Department

Preliminary Investigation of Over-all Performance of Experimental Turbojet Engine for Guided Missiles

Description: A preliminary investigation of the over-all performance of a simply constructed, short-life, turbojet engine was conducted. The unit was operated at a pressure altitude of 15,000 feet for ram-pressure ratios of 1.2 t o 1.8. The corrected engine speed was varied from the minimum for good combustion to about 17,000 rpm, which is approximately 75 percent of rated speed. The performance is given by generalized parameters that permit the calculation of performance at any altitude. The corrected net thrust of the turbojet engine increased with ram-pressure ratio for a given corrected engine speed above 14,500 rpm and reached a maximum of 425 pounds at a ram-pressure ratio of 1.8 and a corrected engine speed of 16,650 rpm, The corrected thrust specific fuel consumption decreased with flight speed for corrected engine speeds higher than 13,600 rpm, The minimum corrected thrust specific fuel consumption of 1.48 was obtained at a ram-pressure ratio of 1,8 and a corrected engine speed of 15,000 rpm. For all ram-pressure ratios, choking occurred in the engine for corrected engine speeds greater than 14,500 rpm.
Date: September 22, 1947
Creator: Eustis, Robert H. & Berkey, William E.
Partner: UNT Libraries Government Documents Department

Some Tests and Calculations Pertaining to the Dive Path and to Wing and Tail Loads in the Accident to Eastern Airlines C54B Airplane, NC-88814, Near Bainbridge, Maryland, May 30, 1947

Description: Several dive paths were calculated for a C54 airplane starting from level flight at an altitude of 4000 feet and from an initial indicated airspeed of 200 miles per hour. The results show that, within the limits of the possible paths permitted by the evidence of the crash at Bainbridge, the speed of impact would be about 370 miles per hour and the time to crash would be between 12 1/2 and 15 1/2 seconds. Tail load calculations indicate that, with moderate negative acceleration of the airplane, the tail would fail near the end of the dive in a manner consistent in several important respects with the evidence. A number of tests were made of the elevator tab control system to determine whether the tab would move by an amount sufficient to have caused the observed dive if the stored energy in the tab control cable were suddenly released. The results of these tests indicated that the probable tab movement is such as to be capable of causing a dive similar to the one observed at Bainbridge.
Date: October 22, 1947
Creator: Rhode, Richard V.; Stokke, Allen R. & Rogin, Leo
Partner: UNT Libraries Government Documents Department

Preliminary Results of Altitude-Wind-Tunnel Investigation of X24C-4B Turbojet Engine. 4 - Performance of Modified Compressor, Part 4, Performance of Modified Compressor

Description: The performance of the 11-stage axial-flow compressor, modified to improve the compressor-outlet velocity, in a revised X24C-4B turbojet engine is presented and compared with the performance of the compressor in the original engine. Performance data were obtained from an investigation of the revised engine in the MACA Cleveland altitude wind tunnel. Compressor performance data were obtained for engine operation with four exhaust nozzles of different outlet area at simulated altitudes from 15,OOO to 45,000 feet, simulated flight Mach numbers from 0.24 to 1.07, and engine speeds from 4000 to 12,500 rpm. The data cover a range of corrected engine speeds from 4100 to 13,500 rpm, which correspond to compressor Mach numbers from 0.30 to 1.00.
Date: December 22, 1947
Creator: Thorman, H. Carl & Dupree, David T.
Partner: UNT Libraries Government Documents Department

Tests of the AN/SPS-1 Radar Antenna in the Langley Full-Scale Tunnel

Description: Tests have been conducted to determine the drive-motor torque and the static force and moment characteristics of the AN/SPS-1 radar antenna. Shifting the longitudinal position of the antenna had very little effect on the drive-motor torque, which reached a maximum value expressed in terms of dynamic pressure (T/q)(sub max) of 1.15 at an azimuth angle of 245. The maximum observed values of rolling, pitching, and yawing moments in terms of dynamic pressure are -29.0, 66.6, and 13.4, respectively.
Date: December 22, 1947
Creator: May, Ralph W., Jr.
Partner: UNT Libraries Government Documents Department

Tests of a triangular wing of aspect ratio 2 in the Ames 12-foot pressure wind tunnel. 1: the effect of Reynolds number and Mach number on the aerodynamic characteristics of the wing with flap undeflected

Description: Report presenting testing of a semispan model of a wing of triangular plan form and aspect ratio 2 in the 12-foot pressure tunnel to determine the aerodynamic characteristics of the wing as influenced by the independent effects of Reynolds number and Mach number up to Mach numbers approaching unity. Results regarding the effect of body and effect of wing-profile modification are also provided.
Date: January 22, 1948
Creator: Edwards, George G. & Stephenson, Jack D.
Partner: UNT Libraries Government Documents Department

Ditching Tests of a 1/20-Scale Model of the Northrop B-35 Airplane

Description: Tests of a 1/20-scale dynamically similar model of the Northrop B-35 airplane were made to study its ditching characteristics. The model was ditched in calm water at the Langley tank no. 2 monorail. Various landing attitudes, speeds,and conditions of damage were simulated during the investigation. The ditching characteristics were determined by visual observation and from motion-picture records and time-history acceleration records. Both longitudinal and lateral accelerations were measured. Results are given in tabular form and time-history acceleration curves and sequence photographs are presented. Conclusions based on the model investigation are as follows: 1. The best ditching of the B-35 airplane probably can be made by contacting the water in a near normal landing attitude of about 9 deg with the landing flaps full down so as to have a low horizontal speed. 2. The airplane usually will turn or yaw but the motion will not be violent. The maximum lateral acceleration will be about 2g. 3. If the airplane does not turn or yaw immediately after landing, it probably will trim up and then make a smooth run or porpoise slightly. The maximum longitudinal decelerations that will be encountered are about 6g or 7g. 4. Although the decelerations are not indicated to be especially large, the construction of the airplane is such that extensive damage is to be expected, and it probably will be difficult to find ditching stations where crew members can adequately brace themselves and be reasonably sure of avoiding a large inrush of water.
Date: February 22, 1948
Creator: Fisher, Lloyd J.
Partner: UNT Libraries Government Documents Department

Vibration of turbine blades in a turbojet engine during operation

Description: Report presenting an experimental investigation to determine the vibration phenomena that occur in turbine blades of a typical jet-propulsion engine during service operation; high-temperature strain gages were used to measure the turbine-blade vibrations. Results regarding modes of vibration, centrifugal stresses, and vibration of turbine blades during operation are provided.
Date: April 22, 1948
Creator: Morgan, W. C.; Kemp, R. H. & Manson, S. S.
Partner: UNT Libraries Government Documents Department

Effect of inlet-air parameters on combustion limit and flame length in 8-inch-diameter ram-jet combustion chamber

Description: Report presenting an investigation with a ram-jet combustion chamber to determine the effect of fuel-air ratio and the inlet-air parameters of pressure, temperature, and velocity on combustion limit, combustion efficiency, and flame length.
Date: July 22, 1948
Creator: Cervenka, A. J. & Miller, R. C.
Partner: UNT Libraries Government Documents Department

Investigation of high-temperature operation of liquid-cooled gas turbines I: turbine wheel of aluminum alloy, a high-conductivity nonstrategic material

Description: Report presenting an investigation of turbine operating temperatures as affected by liquid cooling, especially if materials of high conductivity are used, at gas temperatures up to 1925 degrees Fahrenheit. Results regarding the statio heat-transfer rig and turbine rig are provided. The investigation showed that nonstrategic material such as aluminum alloy can be used in liquid-cooled turbine wheels at high gas temperatures.
Date: July 22, 1948
Creator: Kottas, Harry & Sheflin, Bob W.
Partner: UNT Libraries Government Documents Department

Longitudinal stability characteristics of a 42 degree sweptback wing and tail combination at a Reynolds number of 6.8 x 10(exp 6)

Description: Results of a wind-tunnel investigation at a Reynolds number of 6.8 x 10(exp 6) to determine the static longitudinal stability characteristics of a 42 degree sweptback wing and fuselage combination with a sweptback horizontal tail are provided. Included are the effects of vertical position of fuselage and tail with respect to wing for several combinations of high-lift and staff-control devices. Also included is the effect of a simulated ground.
Date: July 22, 1948
Creator: Spooner, Stanley H. & Martina, Albert P.
Partner: UNT Libraries Government Documents Department