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

Search Results

Stability and Control Data Obtained from Fourth and Fifth Flights of the Northrop X-4 Airplane (A.F. No. 46-676)

Description: NACA instrumentation has been installed in the Northrop X-4 airplane to obtain stability and control data during the Northrop conducted acceptance tests. The results of the fourth and fifth flights of the Northrop X-4 number 1 airplane are presented in this paper. These data were obtained for a center-of-gravity position of approximately 19.5 percent of the mean aerodynamic chord. The results of this flight showed that the directional stability as measured in steadily increasing sideslips was positive and high and that the effective dihedral was positive. The results also show the airplane to be longitudinally stable, stick fixed, with the center of gravity at 19.5 percent of the mean aerodynamic chord.
Date: August 4, 1949
Creator: Valentine, George M
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of a 45 degree swept-back wing with aspect ratio of 3.5 and NACA 2S-50(05)-50(05) airfoil sections

Description: From Introduction: "The present paper presents the scale effect on the longitudinal aerodynamic characteristics, the aerodynamic characteristics in yaw, and the tuft studies for 0^o and 3.7^o yaw. The results of the effect of leading-edge and trailing-edge flaps on the aerodynamic characteristics of the wing will be presented in later reports."
Date: August 4, 1947
Creator: Proterra, Anthony J
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of a 6-percent-thick symmetrical double-wedge airfoil at transonic speeds from tests by the NACA wing-flow method

Description: From Introduction: "The investigation covered a range of Mach numbers from 0.66 to 1.12 and included measurements of angle of attack, pitching moment, normal force, and chord force. The drag at zero lift obtained in this investigation was reported in reference 1, but without the correction for tare of the end plate."
Date: March 4, 1949
Creator: Lina, Lindsay J
Partner: UNT Libraries Government Documents Department

An analysis of a highly compounded two-stroke-cycle compression-ignition engine

Description: This report presents an analysis of a compound engine operating with manifold pressures ranging from 60 to 110 lb/sq in. absolute and discusses the effects of engine limits (peak cylinder pressure and turbine-inlet temperature) and component efficiency.
Date: April 4, 1949
Creator: Tauschek, Max J; Sather, Bernard I & Biermann, Arnold E
Partner: UNT Libraries Government Documents Department

Analysis and experimental observation of pressure losses in ram-jet combustion chambers

Description: From Introduction: "Some experimental data on flame-holder pressure losses have been presented (reference 1 to 4). A theoretical analysis that assume a sudden enlargement of flow area was made at the NACA Lewis laboratory to determine the effect of flame-holder open area and combustion-chamber-inlet Mach number on the pressure losses across flame holders. The results of this analysis were then compared with experimental data obtained with several different flame-holder designs."
Date: November 4, 1949
Creator: Sterbentz, William H
Partner: UNT Libraries Government Documents Department

Preliminary Results of an Altitude-Wind-Tunnel Investigation of a TG-100A Gas Turbine-Propeller Engine II - Windmilling Characteristics

Description: An investigation was conducted to determine the operational and performance characteristics of the TG-100A gas turbine-propeller engine II. Windmilling characteristics were deterined for a range of altitudes from 5000 to 35,000 feet, true airspeeds from 100 to 273 miles per hour, and propeller blade angles from 4 degrees to 46 degrees.
Date: August 4, 1947
Creator: Conrad, E. W. & Durham, J. D.
Partner: UNT Libraries Government Documents Department

Performance of Single-Stage Turbine of Mark 25 Torpedo Power Plant with Two Special Nozzles, 1, Efficiency with 0.45-inch Rotor Blades

Description: An investigation was made of the first-stage turbine of a Mark 25 torpedo power plant to determine the performance of the unity with two nozzle configurations and a special rotor having 0.45-inch blades instead of the standard length of 0.40 inch. Both nozzles had smaller passages than the nozzles of similar shape that were previously investigated. The performance of the nozzle-blade combinations is evaluated in terms of brake, rotor, and blade efficiency as functions of blade-jet speed ratio for three pressure ratios. Over the range of speeds and pressure ratios investigated, the efficiency with the nozzle having rectangular passages (J) was higher than that with a nozzle having circular passages (K). The difference in blade efficiencies varied from less than 0.010 at the lower blade-jet speed ratios for the three pressure ratios investigated to 0.030 at a pressure ratio of 8 and a blade-jet speed ratio of 0.295. The efficiencies with these tow nozzles were generally lower than those obtained with nozzles previously reported in combination with the 0.45-inch blades.
Date: May 4, 1949
Creator: Schum, Harold J. & Whitney, Waren J.
Partner: UNT Libraries Government Documents Department

Tank Tests of a 1/7-Size Powered Dynamic Model of the Grumman XJR2F-1 Amphibian: Spray Characteristics, Take-Off and Landing Stability in Smooth Water - Langley Tank Model 212, TED No. NACA 2378

Description: Tests of a model of the XJR2F-Y amphibian were made in Langley tank no. to determine the spray characteristics and the take-off and landing stability. At a gross load of 22,000 pounds full size, spray entered the propeller disk only at a very narrow range of speeds. The spray striking the flaps was not excessive and no appreciable wetting of the tail surfaces was noted. The trim limits of stability appeared to be satisfactory and the upper-limit porpoising was not violent. The stable range of center-of-gravity locations with flaps set 20deg was well aft of the desired operating range. However, with flaps up, the forward limit was about 18 percent mean aerodynamic chord and the aft limit about 28.5 percent mean aerodynamic chord at a load of 26,000 pounds and with elevators deflected -10deg. Under these conditions the location of the step is considered satisfactory. Tests showed that the effect of water in the nose-wheel well would be to move the forward limit aft about 2-percent mean aerodynamic chord. Without ventilation of the main step, the model skipped during landing at most trims, but this skipping was not violent. With the ventilation, the model skipped lightly only at trims where the afterbody keel was approximately parallel to the water (around 7.5 deg).
Date: December 4, 1946
Creator: Land, Norman S. & Zeck, Howrad
Partner: UNT Libraries Government Documents Department

Altitude-Wind-Tunnel Investigation of the 19B-2, 19B-8 and 19XB-1 Jet- Propulsion Engines, 4, Analysis of Compressor Performance

Description: Investigations were conducted in the Cleveland altitude wind tunnel to determine the performance and operational characteristics of the 19B-2, 19B-8, and 19XS-1 turbojet engines. One objective was to determine the effect of altitude, flight Mach number, and tail-pipe-nozzle area on the performance characteristics of the six-stage and ten-stage axial-flow compressors of the 19B-8 and 19XB-1 engines, respectively, The data were obtained over a range of simulated altitudes and flight Mach numbers. At each simulated flight condition the engine was run over its full operable range of speeds. Performance characteristics of the 19B-8 and 19XB-1 compressors for the range of operation obtainable in the turboJet-engine installation are presented. Compressor characteristics are presented as functions of air flow corrected to sea-level conditions, compressor Mach number, and compressor load coefficient. For the range of compressor operation investigated, changes in Reynolds number had no measurable effect on the relations among compressor Mach number, corrected air flow, compressor load coefficient, compressor pressure ratio, and compressor efficiency. The operating lines for the 19B-8 compressor lay on the low-air-flow side of the region of maximum compressor efficiency; the 19B-8 compressor operated at higher average pressure coefficients per stage and produced a lower over-all pressure ratio than did the 19XB-1 compressor.
Date: April 4, 1947
Creator: Dietz, Robert O. & Kuenzig, John K.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Tests of the 1/25-Scale Powered Model of the Martin JRM-1 Airplane. IV - Tests with Ground Board and with Modified Wing and Hull - TED No. NACA 232, Part 4, Tests with Ground Board and with Modified Wing and Hull, TED No. NACA 232

Description: Wind-tunnel tests were made of a 1/25 scale model of the Martin JRM-1 airplane to determine: (1) The longitudinal stability and control characteristics of the JRM-1 model near the water and lateral and directional stability characteristics with power while moving on the surface of the water, the latter being useful for the design of tip floats; (2) The stability and stalling characteristics of the wing with a modified airfoil contour; (3) Stability characteristics of a hull of larger design gross weight; The test results indicated that the elevator was powerful enough to trim the original model in a landing configuration at any lift coefficient within the specified range of centers of gravity. The ground-board tests for evaluating the aerodynamic forces and moments on an airplane in a simulated cross wind indicate a high dihedral effect in the presence of the ground board and, consequently, during low-speed taxying and take-off, large overturning moments would result which would have to be overcome by the tip floats.
Date: September 4, 1947
Creator: Lockwood, Vernard E. & Smith, Bernard J.
Partner: UNT Libraries Government Documents Department

Measurements in Flight of the Longitudinal-Stability Characteristics of a Republic YF-84A Airplane (Army Serial No. 45-59488) at High Subsonic Mach Numbers

Description: A brief investigation was made of the longitudinal-stability characteristics of a YF-84A airplane (Army Serial No. 45-79488). The airplane developed a pitching-up tendency at approximately 0.80 Mach number which necessitated large push forces and down-elevator deflections for further increases in speed. In steady turns at 35,000 feet with the center of gravity at 28.3 percent mean aerodynamic chord for normal accelerations up to the maximum test value, the control-force gradients were excessive at Mach numbers over 0.78. Airplane buffeting did not present a serious problem in accelerated or unaccelerated flight at 15,000 and 35,000 feet up to the maximum test Mach number of 0.84. It is believed that excessive control force would be the limiting factor in attaining speeds in excess of 0.84 Mach number, especially at altitudes below 35,000 feet.
Date: November 4, 1948
Creator: Turner, Howard L. & Cooper, George E.
Partner: UNT Libraries Government Documents Department

Performance of the 19XB 10-Stage Axial-Flow Compressor

Description: The 19xB compressor, which replaces the 19B coaapreseor and has the same length and diameter 88 the 19B compressor, was designed with 10 stages to deliver 30 pounds of air per second for a pressure ratio of 4.17 at an equivalent speed of 17,000 rpm; the 19B was designed with six stages for a pressure ratio of 2.7 at the same weight flow and speed as the 19XB compressor. The performance characteristics of the new compressor were determined at the NACA Cleveland laboratory at the request of the Bureau of Aeronautics, Navy Department. Results are presented of the investigation made to evaluate the over-all performance of the compressor, the effects of possible leakage past the rotor rear air seal, the effects of inserting instruments in each row of stator blades and in the first row of outlet guide vanes, and the effects of changing the temperature and the pressure of the inlet air. The results of the interstage surveys are also presented.
Date: February 4, 1947
Creator: Downing, Richard M. & Finger, Harold B.
Partner: UNT Libraries Government Documents Department