An approximate method for calculating the effect of surface roughness on the drag of an airplane (open access)

An approximate method for calculating the effect of surface roughness on the drag of an airplane

From Summary: "A method for computing the effect of surface roughness on the drag coefficient of an airplane is presented. Calculated results using this method are compared with experimental results from both flight and wind-tunnel tests. In general, the agreement is believed satisfactory."
Date: July 23, 1947
Creator: Hall, Charles F. & Fitzgerald, Fred F.
System: The UNT Digital Library
The calculation of drag for airfoil sections and bodies of revolution at subcritical speeds (open access)

The calculation of drag for airfoil sections and bodies of revolution at subcritical speeds

Report presenting a method for calculating the drag, in a real compressible fluid and at subcritical Mach numbers, of airfoil sections at arbitrary life coefficients and of bodies of revolution at zero angle of attack. The values of drag coefficient are compared with values obtained for the same configurations by other methods. The differences between the results are found to lie withint he limits of accuracy of current experimental techniques.
Date: April 23, 1947
Creator: Heaslet, Max A. & Nitzberg, Gerald E.
System: The UNT Digital Library
Investigation of the aerodynamic and icing characteristics of a recessed fuel cell vent assembly 3: NACA flush-inlet-type vent (open access)

Investigation of the aerodynamic and icing characteristics of a recessed fuel cell vent assembly 3: NACA flush-inlet-type vent

An investigation conducted in the icing research tunnel to determine aerodynamic and icing characteristics of two flush-inlet-type fuel cell vent installations. The vent tubes were mounted in two different locations in the two installations. The vents were aerodynamically investigated to obtain vent-tube static-pressure differentials and pressure surveys as a function of tunnel-air velocity and angle of attack.
Date: April 23, 1948
Creator: Ruggeri, Robert S.
System: The UNT Digital Library
Low-speed pressure distributions over the drooped-nose flap of a 42 degrees sweptback wing with circular-arc airfoil sections at a Reynolds number of 5.3 x 10(exp 6) (open access)

Low-speed pressure distributions over the drooped-nose flap of a 42 degrees sweptback wing with circular-arc airfoil sections at a Reynolds number of 5.3 x 10(exp 6)

Report presenting an investigation of the pressure distributions over the drooped-nose flap of a 42 degree sweptback wing with circular-arc airfoil sections and half-span trailing-edge split flaps in the 19-foot pressure tunnel. The effects of the deflection and span of the drooped-nose flap and effects of split trailing-edge flaps on the pressures over the drooped-nose flap were determined.
Date: September 23, 1948
Creator: Spooner, Stanley H. & Woods, Robert L.
System: The UNT Digital Library
Wind-Tunnel Investigation at a Mach Number of 1.53 of an Airplane With a Triangular Wing (open access)

Wind-Tunnel Investigation at a Mach Number of 1.53 of an Airplane With a Triangular Wing

Report discusses the results of an investigation into the aerodynamic characteristics of models of a tailless, pursuit-type, supersonic airplane employing a wing of triangular plan form. Measurements of lift, drag, and pitching moment, side force, drag, and yawing moment are described for several angles of attack and angles of yaw. Information about elevator and rudder behavior is also described.
Date: January 23, 1948
Creator: Scherrer, Richard & Wimbrow, William R.
System: The UNT Digital Library
Additional Results in a Free-Flight Investigation of Control Effectiveness of Full-Span, 0.2-Chord Plain Ailerons at High Subsonic, Transonic, and Supersonic Speeds to Determine Some Effects of Wing Sweepback, Aspect Ratio, Taper, and Section Thickness Ratio (open access)

Additional Results in a Free-Flight Investigation of Control Effectiveness of Full-Span, 0.2-Chord Plain Ailerons at High Subsonic, Transonic, and Supersonic Speeds to Determine Some Effects of Wing Sweepback, Aspect Ratio, Taper, and Section Thickness Ratio

Report discussing an aerodynamic control effectiveness study using free-flight, rocket-propelled test vehicles. Information about the effects of wing sweepback, aspect ratio, taper ratio, and section thickness ratio on the rolling effectiveness of full-span, sealed ailerons is provided.
Date: April 23, 1948
Creator: Sandahl, Carl A. & Strass, H. Kurt
System: The UNT Digital Library
The Aerodynamic Effects of Rockets and Fuel Tanks Mounted Under the Swept-Back Wing of an Airplane Model (open access)

The Aerodynamic Effects of Rockets and Fuel Tanks Mounted Under the Swept-Back Wing of an Airplane Model

From Summary: "The effects of externally mounted rockets and fuel tanks on the aerodynamic characteristics of an airplane model with a swept-back wing are presented in this report."
Date: April 23, 1948
Creator: Boddy, Lee E. & Morrill, Charles P., Jr.
System: The UNT Digital Library
Longitudinal Stability and Control Characteristics of a Semispan Airplane Model With a Sweptback Wing and Tail From Tests at Transonic Speeds by the NACA Wing-Flow Method (open access)

Longitudinal Stability and Control Characteristics of a Semispan Airplane Model With a Sweptback Wing and Tail From Tests at Transonic Speeds by the NACA Wing-Flow Method

Report presenting an investigation using the NACA wing-flow method to determine the longitudinal stability and control characteristics at transonic speeds of a semispan airplane with a 45 degree sweptback wing and tail. Measurements of the lift and angle of attack for trim were made for several stabilizer and elevator settings. Testing was also performed to investigate the effects of transition wires mounted on the wing and tail, the effect of increasing the boundary-layer thickness on the test surface, and the effectiveness of a wing flap with a sweepback of 45 degrees.
Date: July 23, 1948
Creator: Sawyer, Richard H. & Lina, Lindsay J.
System: The UNT Digital Library
Some Flight Measurements of Pressure-Distribution and Boundary-Layer Characteristics in the Presence of Shock (open access)

Some Flight Measurements of Pressure-Distribution and Boundary-Layer Characteristics in the Presence of Shock

Memorandum presenting some pressure-distribution and boundary-layer measurements made in flight in the presence of shock on two modifications of the local contour of the wings of a high-speed airplane. Results regarding the pressure distribution, boundary-layer surveys, and effects on test airplane are provided.
Date: July 23, 1948
Creator: Zalovcik, John A. & Luke, Ernest P.
System: The UNT Digital Library
Empirical mode constants for calculating frequencies of axial-flow compressor blades (open access)

Empirical mode constants for calculating frequencies of axial-flow compressor blades

The vibration characteristics of a group of axial-flow compressor blades of similar geometry were investigated. Empirical-mode constants were determined for the first three bending and torsional modes. A comparison of experimentally determined frequencies of a second group of blades with frequencies computed using these mode constants showed that the computed values were correct within 10 percent. The approximate limiting ratios of depth to chord and length to chord below which these constants could not be used to compute the natural frequencies were also found experimentally.
Date: April 23, 1948
Creator: Millenson, M. B. & Wilterdink, P. I.
System: The UNT Digital Library
A limit pressure coefficient and an estimation of limit forces on airfoils at supersonic speeds (open access)

A limit pressure coefficient and an estimation of limit forces on airfoils at supersonic speeds

Report presenting the results of an estimation of the limit forces on airfoils at supersonic speeds. The limit pressure coefficient attainable on an airfoil is shown to be about 70 percent of the pressure coefficient for a vacuum over a wide range of Mach numbers.
Date: August 23, 1948
Creator: Mayer, John P.
System: The UNT Digital Library
Transonic-Flutter Investigation of Wings Attached to Two Low-Acceleration Rocket-Propelled Vehicles (open access)

Transonic-Flutter Investigation of Wings Attached to Two Low-Acceleration Rocket-Propelled Vehicles

Two low-acceleration transonic-flutter vehicles were launched and flown. The first carried two test wings, one of which fluttered at M = 0.92 at a frequency of 61.4 cycles per second. The reference flutter speed determined from two-dimensional theory for an unswept wing in incompressible flow is conservative when compared to the experimental flutter speed. The second vehicle carried two test wings, one of which failed at M = 0.71 because of low-frequency divergent oscillation. Since this failure was not caused by conventional flexure-torsion flutter, no comparison with a reference flutter speed can be made.
Date: November 23, 1948
Creator: Lundstrom, Reginald R.; Lauten, William T., Jr. & Angle, Ellwyn E.
System: The UNT Digital Library
Altitude-chamber performance of British Rolls-Royce Nene II engine 1: standard 18.75-inch-diameter jet nozzle (open access)

Altitude-chamber performance of British Rolls-Royce Nene II engine 1: standard 18.75-inch-diameter jet nozzle

Report presenting an altitude-chamber investigation to determine the altitude performance characteristics of the British Rolls-Royce Nene II turbojet engine with a standard 18.75-inch-diameter jet nozzle. Results regarding the simulated flight performance and generalized performance across other altitude and pressure characteristics are provided.
Date: September 23, 1949
Creator: Barson, Zelmar & Wilsted, H. D.
System: The UNT Digital Library
Flight-Test Measurements of Aileron Control Surface Behavior at Super Critical Mach Numbers (open access)

Flight-Test Measurements of Aileron Control Surface Behavior at Super Critical Mach Numbers

Report presenting measurements of the behavior at supercritical Mach numbers of ailerons on a jet-propelled fighter plane. Results regarding aileron upfloat and aileron oscillations are provided.
Date: April 23, 1947
Creator: Brown, Harvey H.; Rathert, George A., Jr. & Clousing, Lawrence A.
System: The UNT Digital Library
Estimation of Lift and Drag of Airfoils at Near Sonic Speeds and in the Presence of Detached Shock Waves (open access)

Estimation of Lift and Drag of Airfoils at Near Sonic Speeds and in the Presence of Detached Shock Waves

Report presenting a semiempirical method of estimating the forces on airfoil at near sonic speeds and in the presence of detached shock waves. The calculated values were found to be in good agreement with wind-tunnel testing of the forces on sharp-nose airfoils and two-dimensional wings.
Date: February 23, 1949
Creator: Mayer, John P.
System: The UNT Digital Library
Aerodynamic Characteristics of a 42 Degree Swept-Back Wing With Aspect Ratio 4 and NACA 64(Sub 1)-112 Airfoil Sections at Reynolds Numbers From 1,700,000 to 9,500,000 (open access)

Aerodynamic Characteristics of a 42 Degree Swept-Back Wing With Aspect Ratio 4 and NACA 64(Sub 1)-112 Airfoil Sections at Reynolds Numbers From 1,700,000 to 9,500,000

Report discussing testing on a 42 degree swept-back wing to determine its low-speed aerodynamic characteristics in pitch and yaw at high Reynolds numbers. The main effect of increasing the Reynolds number was delayed wing stalling to higher angles of attack. Roughness on the wing leading edge also had a large adverse effect on lift, drag, and pitching-moment characteristics at higher Reynolds numbers.
Date: May 23, 1947
Creator: Neely, Robert H. & Conner, D. William
System: The UNT Digital Library
Operating Temperatures of I-40-5 Turbojet Engine Burner Liners and the Effect of Temperature Variation on Burner-Liner Service Life (open access)

Operating Temperatures of I-40-5 Turbojet Engine Burner Liners and the Effect of Temperature Variation on Burner-Liner Service Life

Report presenting an investigation of burner liners in a turbojet engine to determine the principal factors limiting the burner-liner service life. The investigation covered a range of engine speeds and testing was conducted to determine whether bare, ceramic-coated, or shielded thermocouples would give the most correct temperature readings.
Date: August 23, 1948
Creator: Wilsted, H. D.; Duffy, Robert T. & Grey, Ralph E.
System: The UNT Digital Library
Free-flight investigation of the rolling effectiveness at high subsonic, transonic, and supersonic speeds of leading-edge and trailing-edge ailerons in conjunction with tapered and untapered plan forms (open access)

Free-flight investigation of the rolling effectiveness at high subsonic, transonic, and supersonic speeds of leading-edge and trailing-edge ailerons in conjunction with tapered and untapered plan forms

Report presenting several rectangular and tapered wing configurations with leading-edge and trailing-edge ailerons tested as part of a general investigation of an aerodynamic control at supersonic speeds. Results indicated that the use of the leading-edge aileron alone was ineffective or caused negative control until a high Mach number was attained. Results for the untapered configurations, tapered configurations, and drag measurements are provided.
Date: July 23, 1948
Creator: Strass, H. Kurt
System: The UNT Digital Library
Residual Stress Analysis of Overspeeded Disk With Central Hole by X-Ray Diffraction (open access)

Residual Stress Analysis of Overspeeded Disk With Central Hole by X-Ray Diffraction

An X-ray - diffraction analysis of residual surface stresses after plastic strain was introduced in a parallel-sided 3S-O aluminum disk with a central hole by two types of centrifugal overspeed is reported. Both tangential and radial stresses were generally tensile with large local variations near the hole where surface stresses may have been partly superficial. These stresses were both tensile and compressive dependent on the distance from the disk center when mass compression was effected near the hole.
Date: July 23, 1948
Creator: Good, James N.
System: The UNT Digital Library
Low-speed wind-tunnel investigation of the longitudinal stability characteristics of a model equipped with a variable-sweep wing (open access)

Low-speed wind-tunnel investigation of the longitudinal stability characteristics of a model equipped with a variable-sweep wing

Report presenting an investigation to determine the longitudinal stability characteristics of a complete model equipped with a variable-sweep wing at four different angles of sweepback. The primary objective was to study various wing modifications and an external-flap arrangement designed to minimize the shift in neutral point accompanying the change in sweep angle.
Date: May 23, 1949
Creator: Donlan, Charles J. & Sleeman, William C., Jr.
System: The UNT Digital Library
Wind-Tunnel investigation of NACA 65,3-418 airfoil section with boundary-layer control through a single suction slot applied to a plain flap (open access)

Wind-Tunnel investigation of NACA 65,3-418 airfoil section with boundary-layer control through a single suction slot applied to a plain flap

Report presenting an investigation in the two-dimensional low-turbulence tunnel of the NACA 65,3-418 airfoil section with a 25-percent-airfoil-chord plain flap and a suction slot on the flap. The primary purpose of the investigation is to determine the effect of the type of boundary-layer control on the section lift-drag ratio.
Date: February 23, 1949
Creator: Horton, Elmer A. & von Doenhoff, Albert E.
System: The UNT Digital Library
Force, Static Longitudinal Stability, and Control Characteristics of a 1/16-Scale Model of the Bell XS-1 Transonic Research Airplane at High Mach Numbers (open access)

Force, Static Longitudinal Stability, and Control Characteristics of a 1/16-Scale Model of the Bell XS-1 Transonic Research Airplane at High Mach Numbers

Report presenting results obtained to determine the effects of compressibility at high Mach numbers on a scale model of the Bell XS-1 transonic research airplane. The results are presented for several model configurations through a range of Mach numbers. Results regarding aerodynamic characteristics and static longitudinal stability characteristics are provided.
Date: June 23, 1948
Creator: Mattson, Axel T. & Loving, Donald L.
System: The UNT Digital Library
Some Effects of Stator Cone Angle and Blade-Tip Leakage on 40 Percent Reaction Turbine Having Rotor-Blade Caps (open access)

Some Effects of Stator Cone Angle and Blade-Tip Leakage on 40 Percent Reaction Turbine Having Rotor-Blade Caps

Memorandum presenting an investigation of the effects of stator cone angle and tip leakage on turbine performance. A single-stage turbine with 40-percent reaction was operated with two stators and two stationary shrouds. The turbine was operated at an entrance temperature of 660 degrees R with total-pressure ratios from 1.25 to 3.70 and equivalent mean blade speeds from 166 to 655 feet per second.
Date: March 23, 1949
Creator: English, Robert E.; McCready, Robert J. & McCarthy, John S.
System: The UNT Digital Library
Tests of Submerged Duct Installation on the Ryan FR-1 Airplane in the Ames 40- by 80-Foot Wind Tunnel (open access)

Tests of Submerged Duct Installation on the Ryan FR-1 Airplane in the Ames 40- by 80-Foot Wind Tunnel

"An investigation of an NACA submerged intake installation on the Ryan FR-1 was conducted to determine the full-scale aerodynamic characteristics of this installation. In addition, tests were conducted on the submerged inlet with revised entrance lips and deflectors to determine the configuration which would result in the best dynamic pressure recovery measured at the inlet for this installation without a major rework of the entrance. Stalling of the air flow over the inner lip surface created excessive dynamic pressure losses with the original entrance. The revised entrance produced a 12-percent increase in dynamic pressure recovery at the design high-speed inlet-velocity ratio and resulted in an improvement of the critical-speed characteristics of the entrance lip" (p. 1).
Date: April 23, 1947
Creator: Martin, Norman J.
System: The UNT Digital Library