National Advisory Committee for Aeronautics (NACA) - 39 Matching Results

Search Results

Flight and wind-tunnel investigation to determine the aileron-vibration characteristics of 1/4-scale wing panels of the Douglas D-558-2 research airplane

Description: Report presenting a flight and wind-tunnel investigation to determine the aerodynamic vibration characteristics of ailerons for the Douglas D-558-2 airplane. Testing was conducted to investigate the possibilities of a single-degree-of-freedom flutter known as aileron "buzz" or aileron compressibility flutter. Results regarding the three types of aileron vibration observed and vibration amplitudes are provided.
Date: November 30, 1948
Creator: Angle, Ellwyn E. & Lundstrom, Reginald R.
Partner: UNT Libraries Government Documents Department

The aerodynamic characteristics throughout the subsonic speed range of a thin, sharp-edged horizontal tail of aspect ratio 4 equipped with a constant-chord elevator

Description: From Introduction: "Recent investigations have indicated several wing plan forms, wing sections, and wing-body-tail combinations suitable for flight at supersonic speeds. One such lifting surface, a thin, sharp-edged without sweep of aspect ratio 4 and taper ratio 0.5, has been the subject of an investigation in the Ames 12-foot pressure wind tunnel. The aim of the investigation was to determine the aerodynamic characteristics of such a wing plan form throughout the range of subsonic Mach numbers up to 0.94."
Date: June 30, 1949
Creator: Bandettini, Angelo & Reed, Verlin D
Partner: UNT Libraries Government Documents Department

Experimental investigation of performance and operating characteristics of a tail-pipe burner for a turbojet engine

Description: Report presenting an investigation to obtain fundamental information required for the design of a satisfactory tail-pipe burner for augmenting turbojet engine thrust. Investigations were also conducted to determine the combustion and pressure-drop characteristics of the most satisfactory burner, to develop a method of controlling the burner-outlet temperature distribution, and to improve the burner ignition characteristics.
Date: October 30, 1947
Creator: Gabriel, David S.; Martinson, E. Vincent & Essig, Robert H.
Partner: UNT Libraries Government Documents Department

A summary and analysis of wind-tunnel data on the lift and hinge-moment characteristics of control surfaces up to a Mach number of 0.90

Description: Report presenting an extensive collection of lift and hinge-moment characteristics of control surfaces up to a Mach number of 0.90 in a high-speed wind tunnel. A wide variety of control-surface profiles, plan forms, and aerodynamic balances are included. Results regarding elevator hinge moments and longitudinal control, aileron hinge moments and lateral control, control-surface characteristics, and transonic flutter are highlighted.
Date: April 30, 1948
Creator: Axelson, John A.
Partner: UNT Libraries Government Documents Department

High-speed wind-tunnel investigation of a flying-boat hull with high length-beam ratio

Description: Report presenting the results of an investigation to determine the effect of Mach number on the aerodynamic characteristics of a flying-boat hull with a high length-beam ratio. Information about the drag coefficients, angles of attack for minimum drag, and longitudinal and directional stability is provided.
Date: June 30, 1948
Creator: Riebe, John M. & Naeseth, Rodger L.
Partner: UNT Libraries Government Documents Department

Measurements of the damping in roll of large-scale swept-forward and swept-back wings

Description: Report presenting wind-tunnel testing of five large-scale tapered wings with a variety of angles of sweep to determine the effects of scale and sweep on the damping-in-roll parameter. Rolling moment and pressure distribution were measured for each plain wing while in steady roll for a range of angles of attack. Results regarding the effects of sweep at zero lift, effects of lift, and aurorotational characteristics are provided.
Date: July 30, 1947
Creator: Hunton, Lynn W. & Dew, Joseph K.
Partner: UNT Libraries Government Documents Department

Application of an ultraviolet spectrophotometric method to the estimation of alkylnaphthalenes in 10 experimental jet-propulsion fuels

Description: Report presenting the combustion efficiencies of 10 experimental jet-propulsion fuels that are approximately 200 degrees Fahrenheit cuts of five selected crudes available in large quantities in a turbojet engine combustor at altitude conditions.
Date: April 30, 1947
Creator: Cleaves, Alden P. & Carver, Mildred S.
Partner: UNT Libraries Government Documents Department

Flight Investigations at High-Subsonic, Transonic, and Supersonic Speeds to Determine Zero-Lift Drag of Fin-Stabilized Bodies of Revolution having Fineness Ratios of 12.5, 8.91, and 6.04 and Varying Positions of Maximum Diameter

Description: Rocket-powered models were flown at high-subsonic, transonic, and supersonic speeds to determine the zero-lift drag of fin-stabilized parabolic bodies of revolution differing in fineness ratio and in position of maximum diameter. The present paper presents the results for fineness ratio 12.5, 8.91 and 6.04 bodies having maximum diameters located at stations of 20, 40, 60, and 80 percent of body length. All configurations had cut-off sterns and all had equal base, frontal, and exposed fin areas. For most of the supersonic-speed range models having their maximum diameters at the 60-percent station gave the lowest values of drag coefficient. At supersonic speeds, increasing the fineness ratio generally reduced the drag coefficient for a given position of maximum diameter.
Date: November 30, 1949
Creator: Hart, Roger G. & Katz, Ellis R.
Partner: UNT Libraries Government Documents Department

Flight and test-stand investigation of high-performance fuels in double-row radial air-cooled engines 2: flight knock data and comparison of fuel knock limits with engine cooling limits in flight

Description: Report discussing a comparison of the antiknock characteristics of triptane with a temperature-sensitive blending agent and of the fuel knock limits with engine cooling limits. Estimates were also made of temperature-limited engine performance at several flight and engine conditions.
Date: December 30, 1944
Creator: White, H. Jack; Blackman, Calvin C. & Werner, Milton
Partner: UNT Libraries Government Documents Department

Operating stresses in aircraft-engine crankshafts and connecting rods 1: slip-ring and bush combinations for dynamic-strain measurements

Description: From Summary: "Tests were conducted to develop a slip-ring and brush system that will perform satisfactorily in aircraft-engine, dynamic-strain-measuring applications where resistance-wire strain gages are the means of measuring the strain and to correlate the data obtained from tests in order to provide a basis for predicting the performance of similar slip-ring and brush systems operating under conditions similar to those imposed by these tests." 24 combinations of materials were tested dry and 8 were tested in oil. The five most predictable systems were identified.
Date: March 30, 1945
Creator: Dutee, Francis J.; Phillips, Franklyn W. & Kemp, Richard H.
Partner: UNT Libraries Government Documents Department

Buffeting of External Fuel Tanks at High Speeds on a Grumman F7F-3 Airplane

Description: Attempts were made to alleviate the buffeting of external fuel tanks mounted under the wings of a twin-engine Navy fighter plane. The Mach number at which the buffeting began was increased from 0.529 to 0.640 by streamlining the sway braces and increasing the lateral rigidity of the sway brace system. Further increases of the Mach number, at which buffeting began to 0.725, was obtained by moving the external fuel tank to a position under the fuselage.
Date: January 30, 1947
Creator: Turner, Howard L.
Partner: UNT Libraries Government Documents Department

Correlation of wind-tunnel predictions with flight tests of a twin-engine patrol airplane 2: lateral- and directional-stability and control characteristics

Description: From Summary: "The lateral- and directional-stability and -control characteristics of a twin-engine patrol airplane as predicted from the results of wind-tunnel tests of a powered model and as measured in flight are compared in this report. The predictions from wind-tunnel-test data were in good agreement with the flight-test results. The results show that such predicted flying-qualities characteristics are sufficiently accurate to indicate the unsatisfactory lateral- and directional-stability and -control characteristics of airplanes in the preliminary design stage."
Date: August 30, 1945
Creator: Delany, Noel K. & Kauffman, William M.
Partner: UNT Libraries Government Documents Department

Estimates of the vertical-tail loads of a Bell P-63A-1 airplane (AAF No. 42-68889) in accelerated rolling maneuvers based on flight tests with two vertical-tail arrangements

Description: Report discussing the results of using an enlarged vertical tail on a P-63A-1 on directional stability. The tests included measurements of the amount of sideslip at various speeds and normal accelerations. Potential required modifications for increased performance using the larger tail are also described.
Date: November 30, 1944
Creator: Johnson, Harold I.
Partner: UNT Libraries Government Documents Department

Surface-pressure distributions on a systematic group of NACA 1-series cowlings with and without spinners

Description: From Summary: "A method for calculating the flow fields of axially symmetric bodies from their pressure distributions is reported in NACA RM No. L8I17. In order to facilitate application of this method to the important case of the cowling-spinner combination, for use in the design of propellers, the present paper presents static-pressure distributions on the tops of 79 high-critical-speed NACA 1-series cowling-spinner combinations over wide ranges of inlet-velocity ratio at angles of attack of 0 degrees, 2 degrees, 4 degrees, and 6 degrees. Static-pressure distributions around the nose sections of several cowlings are given in greater detail to aid in estimating the pressures near the stagnation points and to show the effect of changes in the internal lip shape."
Date: November 30, 1948
Creator: Boswinkle, Robert W., Jr. & Keith, Arvid L., Jr.
Partner: UNT Libraries Government Documents Department

Free-Spinning-Tunnel Tests of a 1/18-Scale Model of the Fairchild XNQ-1 Airplane, TED No. NACA 2398

Description: Spin tests have been performed in the Langley 20-foot free-spinning tunnel on a 1/18-scale model of the Fairchild XNQ-1 airplane. The spin and recovery characteristics of the model were determined for the normal gross-weight loading and for two variations from this loading - center of gravity moved rearward and relative mass distribution increased along the fuselage. These tests were performed for two vertical-tail plan forms. The investigation also included simulated pilot-escape tests and rudder-force tests. The recovery characteristics of the model were satisfactory for all conditions tested by full reversal of the rudder and by simultaneous neutralization of the rudder and elevator. It was indicated that if necessary to escape from the spinning airplane, the pilot should jump from the outboard side of the fuselage and as far rearward as possible. Aa determined from spin model tests, the rudder pedal force required to reverse the rudder for recovery from the spin will be light.
Date: September 30, 1946
Creator: Daughtridge, Lee T., Jr.
Partner: UNT Libraries Government Documents Department

Evaluation of Gust and Draft Velocities from Flights of P-61C Airplanes within Thunderstorms: August 23, 1946 to September 4, 1946 at Orlando, Florida

Description: This report presents the results obtained from gust and draft velocity measurements within thunderstorms for the period August 23, 1946 to September 4, 1946 at Orlando, Florida. These data are summarized in tables I end II and are of the type presented in reference 1 for previous flights. In several of the surveys, indications of ambient air temperature were obtained from photo-observer records. These data are summarized in table III.
Date: January 30, 1946
Creator: Tolefson, H. B.
Partner: UNT Libraries Government Documents Department

Preliminary Tests of a Buffet Stall-Warning Device on a 1/5-Scale Model of the Republic XP-84 Airplane

Description: During the first flight tests of the Republic XP-84 airplane it was discovered that there was a complete lack of stall warning. A short series of development tests of a suitable stall-warning device for the airplane was therefore made on a 1/5-scale model in the Langley 300 MPH 7- by 10-foot tunnel. Two similar stall-warning devices, each designed to produce early root stall which would provide a buffet warning, were tested. It appeared that either device would give a satisfactory buffet warning in the flap-up configuration, at the cost of an increase of 8 or 10 miles per hour in minimum speed. Although neither device seemed to give a true buffet warning in the flaps-down configuration, it appeared that either device would improve the flaps-down stalling characteristics by lessening the severity of the stall and by maintaining better control at the stall. The flaps-down minimum-speed increase caused by the devices was only 1 or 2 miles per hour.
Date: October 30, 1946
Creator: Tucker, Warren A. & Comisarow, Paul
Partner: UNT Libraries Government Documents Department

Effects of Compressibility on the Flow Past Thick Airfoil Sections

Description: Six, 3-inch-chord symmetrical airfoil sections having systematic variations in thickness and thickness location were tested at Mach numbers near flight values for propeller-shank sections. The tests, the results of which are presented in the form of schlieren photographs of the flow past each model and pressure-distribution charts for two of the model, were performed to illustrate the effects of compressibility on the flow past thick symmetrical airfoil sections. Representative flow photographs indicated that at Mach numbers approximately 0.05 above the critical Mach number a speed region was reached in which the flow oscillated rapidly and the separation point and the location of the shock wave were unstable. Fixing the transition on both surfaces of the airfoil was effective in reducing these rapid oscillations. The pressure distributions showed that the section normal-force coefficients for thick airfoils were very erratic at subcritical speeds; at supercritical speeds the section normal-force coefficients for the thick airfoils became more regular. Drag coefficients showed that considerable drag decreases can be expected by decreasing the model thickness ratio.
Date: January 30, 1947
Creator: Daley, Bernard N. & Humphreys, Milton D.
Partner: UNT Libraries Government Documents Department

Effect of Slot-Entry Skirt Extensions on Aerodynamic Characteristics of a Wing Section of the XB-36 Airplane Equipped with a Double Slotted Flap

Description: An investigation was made in the Langley two-dimensional low-turbulence tunnel on a wing section for the XB-36 airplane equipped with a double slotted flap to determine the effect on lift and drag of various slot-entry skirt extension. A skirt extension of 0.787 deg. was found to provide the best combination of high maximum lift with flap deflected and law drag with flap retracted. The data showed that the maximum lift at intermediate (20 deg. to 45 deg.) flap deflections was lowered considerably by the slot-entry extension; but at high flap deflections the effect was small. An increase in Reynolds number from 2.4 million to 6.0 million increased the maximum.lift coefficient at a flap deflection of 55 deg. from 3.12 to 3.30 and from 1.18 to 1.40 for the flap retracted condition, but did not greatly affect the maximum lift coefficient for intermediate flap deflections. The flap and fore flap load data indicated that the maximum lift coefficients at high flap deflections are limited by a breakdown in the flow over the .flaps.
Date: June 30, 1947
Creator: Cahill, Jones F.
Partner: UNT Libraries Government Documents Department

Performance of J-33-A-21 Turbojet-Engine Compressor I - Over-All Performance Characteristics at Equivalent Impeller Speeds from 6000 to 13,400 RPM

Description: The NACA is investigating a series of J-33 turbojet-engine compressors to determine the over-all and component performances and to improve theories of flow through large centrifugal compressors, The production model J-33-A-21 was operated over a range of inlet temperatures from 80 to -40 F and inlet pressures from 14 to 5 inches mercury absolute for equivalent impeller speeds from 6000 to 13,400 rpm. At the equivalent design speed of 11,500 rpm, the compressor had a peak pressure ratio of 3.98 at an equivalent weight flow of 73.4 pounds per second and an adiabatic temperature-rise , efficiency of 0.701. When the compressor speed was reduced from the design speed to 6000 rpm, the adiabatic temperature-rise efficiency increased to 0.747. At the maximum equivalent speed investigated (13,400 rpm), a peak pressure ratio of 5.09 was obtained at an adiabatic temperature-rise efficiency of 0.617 and an equivalent weight flow of 66.O pounds per second. An increase in inlet pressure from 5.5 to 14 inches mercury absolute, with a consequent increase in Reynolds number index, improved the pressure ratio but had no apparent effect on the ratio of temperature rise through the compressor to inlet temperature. The variation of the peak adiabatic temperature-rise efficiency with inlet pressure is in the direction that would be expected from a Reynolds number effect. Decrease in the inlet temperature from 80 to -40 F, with a consequent increase in Reynolds number index, resulted in scatter of the pressure-ratio data and increased values of temperature ratio. The variation of the adiabatic temperature-rise efficiency with inlet temperature is probably the result of heat-transfer effects and scatter in the pressure ratio.
Date: March 30, 1948
Creator: Beede, William L.; Kovach, Karl & Creagh, John W. R.
Partner: UNT Libraries Government Documents Department