A Discussion of the Application of the Prandtl-Glauert Method to Subsonic Compressible Flow Over a Slender Body of Revolution (open access)

A Discussion of the Application of the Prandtl-Glauert Method to Subsonic Compressible Flow Over a Slender Body of Revolution

Note presenting an analysis of the use of the Prandtl-Glauert method for subsonic potential flow of a compressible fluid. This paper specifically focuses on the difference between the two- and three-dimensional flow when using this method.
Date: September 1946
Creator: Lees, Lester
System: The UNT Digital Library
Methods for Determination and Computation of Flow Patterns of a Compressible Fluid (open access)

Methods for Determination and Computation of Flow Patterns of a Compressible Fluid

Note presenting a well-known method of generating stream functions of an incompressible fluid flow, which involves taking the imaginary part of an analytic function of a complex variable. This paper is specifically devoted to a detailed discussion of performing computations related to obtaining flow patterns of compressible fluid from analytic functions of a compressible fluid. An example is also provided to illustrate the method.
Date: September 1946
Creator: Bergman, Stefan
System: The UNT Digital Library
The effect of engine variables on the prediction-limited performance of three fuels (open access)

The effect of engine variables on the prediction-limited performance of three fuels

Report presenting preignition-limited performance data for S reference fuel, diisobutylene, and benzene with an engine-heated hot spot on a supercharged CFR engine at 11 sets of engine operating conditions. Results indicated that increases in compression ratio, spark advance, coolant temperature, or inlet-air temperature decreased the preignition-limited indicated mean effective pressure of all three fuels.
Date: September 1946
Creator: Male, Donald W.
System: The UNT Digital Library
Investigation of the Aileron and tab of a spring-tab lateral-control system in the Langley 19-foot pressure tunnel (open access)

Investigation of the Aileron and tab of a spring-tab lateral-control system in the Langley 19-foot pressure tunnel

Report presenting tests of a partial-span model of a large bomber-type airplane, which were conducted to provide data on the aerodynamic characteristics of the aileron-tab arrangement and of the wing. Testing occurred to determine the rolling-moment, yawing-moment, and hinge-moment characteristics of the aileron and tab and the effect of midchord wing slots on the characteristics of the wing and aileron and tab. Results regarding the aerodynamic and stalling characteristics of the wing and aerodynamic characteristics of the aileron and tab are provided.
Date: September 1947
Creator: Deters, Owen J. & Russell, Robert T.
System: The UNT Digital Library
An Electron Microscope Study of Used Nitrated-Steel Piston Rings (open access)

An Electron Microscope Study of Used Nitrated-Steel Piston Rings

Note presenting a study of the altered surface layers found on nitrided-steel piston rings run in nitrided-steel cylinder barrels in order to determine the physical and chemical characteristics of the altered layers and the mechanism by which the coating layers were formed. An electron and a light microscope were used to study different aspects of the materials.
Date: September 1946
Creator: Clark, Thomas P. & Vierthaler, Walter A.
System: The UNT Digital Library
Investigation of the Stability of the Laminar Boundary Layer (open access)

Investigation of the Stability of the Laminar Boundary Layer

Note presenting an investigation of the stability of two-dimensional laminar flows of a gas by the method of small perturbations. The chief emphasis is placed on the case of the laminar boundary layer.
Date: September 1946
Creator: Lees, Lester & Lin, Chia Chiao
System: The UNT Digital Library
Stress Rupture of Heat Resisting Alloys as a Rate Process (open access)

Stress Rupture of Heat Resisting Alloys as a Rate Process

Note presenting the application of the equations of the theory of rate processes to stress rupture in order to predict the experimental stress and temperature dependence of the time for rupture for three heat-resisting alloys. Results regarding stress dependence, temperature dependence of slope factor, and temperature dependence of apparent free energy of activation are provided.
Date: September 1946
Creator: Machlin, E. S. & Nowick, A. S.
System: The UNT Digital Library
The results of wind-tunnel tests to a Mach number of 0.90 of a four-engine, propeller-driven airplane configuration having a wing with 40 degrees of sweepback and an aspect ratio of 10 (open access)

The results of wind-tunnel tests to a Mach number of 0.90 of a four-engine, propeller-driven airplane configuration having a wing with 40 degrees of sweepback and an aspect ratio of 10

Report presenting a wind-tunnel investigation to provide data for the study of the effects of operating propellers on the longitudinal characteristics of a four-engine tractor airplane configuration with a wing of 40 degrees of sweepback and an aspect ratio of 10. Coefficients of lift, longitudinal force, pitching moment, propeller thrust, and propeller power are presented in tabular form for various values of advance ratio at constant angles of attack.
Date: September 1956
Creator: Edwards, George G.; Dickson, Jerald K.; Sutton, Fred B. & Demele, Fred A.
System: The UNT Digital Library
Supersonic flow past nonlifting bumped and indented bodies of revolution (open access)

Supersonic flow past nonlifting bumped and indented bodies of revolution

Linear-theory values of the supersonic pressure field and wave drag of nonlifting bumped and indented bodies of revolution are presented and compared with the corresponding properties of a smooth body. The comparisons indicate that relatively small surface irregularities cause large pressure disturbances and changes in wave drag. The interference drag produced by bumps and indentations is discussed and a correction for the curvature of the characteristics is applied.
Date: September 1956
Creator: McLean, F. Edward & Rennemann, Conrad, Jr.
System: The UNT Digital Library
Examples of three representative types of airfoil-section stall at low speed (open access)

Examples of three representative types of airfoil-section stall at low speed

Report presenting force, moment, pressure-distribution, and boundary-layer measurements for a series of five airfoil sections. The stalling characteristics of the three airfoil sections at low speeds can be separated into three types. A deeper discussion of the role of boundary-layer flow and separation processes in relation to stalling and the sensitivity of stall to factors that influence boundary-layer growth is provided.
Date: September 1951
Creator: McCullough, George B. & Gault, Donald E.
System: The UNT Digital Library
Some dynamic effects of fuel motion in simplified model tip tanks on suddenly excited bending oscillations (open access)

Some dynamic effects of fuel motion in simplified model tip tanks on suddenly excited bending oscillations

Report presenting an exploratory investigation of the dynamic effects of fuel sloshing in tip tanks on suddenly excited bending oscillations using two simplified model beam-tank systems. Several fluids of different densities and viscosities were used in combination with various conditions of tank fullness. Results regarding the large and small beam-tank system are provided.
Date: September 1952
Creator: Merten, Kenneth F. & Stephenson, Bertrand H.
System: The UNT Digital Library
flow studies in the vicinity of a modified flat-plate rectangular wing of aspect ratio 0.25 (open access)

flow studies in the vicinity of a modified flat-plate rectangular wing of aspect ratio 0.25

Report presenting an investigation in order to study the characteristics of flow in the vicinity of a rectangular wing of aspect ratio 0.25 with a modified flat-plate airfoil section. The investigation was conducted using photographs of a tuft grid located at a number of chordwise positions along the airfoil and behind the trailing edge. Results regarding the force-tests, formation of vortices and vorticity distribution in the wake, location of vortex cores, and chordwise growth of lift are provided.
Date: September 1952
Creator: Michael, William H., Jr.
System: The UNT Digital Library
Correlation of Tensile Strength, Tensile Ductility, and Notch Tensile Strength With the Strength of Rotating Disks of Several Designs in the Range of Low and Intermediate Ductility (open access)

Correlation of Tensile Strength, Tensile Ductility, and Notch Tensile Strength With the Strength of Rotating Disks of Several Designs in the Range of Low and Intermediate Ductility

Report presenting burst testing conducted on several designs of sound disks and disks with defects. Results were compared with tensile strength, tensile ductility, and notch tensile strength. The main purpose of the investigation was to determine the extent to which disk strength can be increased by increasing tensile strength, to investigate the extent to which a correlation exists between disk strength and mechanical properties, and to present data on the influence of several types of stress concentration on the strength of disks made from ductile and brittle materials.
Date: September 1952
Creator: Holms, Arthur G. & Repko, Andrew J.
System: The UNT Digital Library
Some Observations on the Relationship Between Fatigue and Internal Friction (open access)

Some Observations on the Relationship Between Fatigue and Internal Friction

Results are presented of an investigation made to determine the internal friction and fatigue strength of commercially pure 1100 aluminum under repeated stressing in torsion at various temperatures and stress levels in an effort to find if there exists any correlation between internal friction and fatigue characteristics.
Date: September 1956
Creator: Valluri, S. R.
System: The UNT Digital Library
Introduction to Electrical-Circuit Analogies for Beam Analysis (open access)

Introduction to Electrical-Circuit Analogies for Beam Analysis

Note presenting an application of the well-known analogy between electrical and mechanical systems to the calculation of stresses and deflections of beams. The main objective of the paper is to give an explanation of the analogies in a basic manner which will enable a structural engineer to understand the process of designing the electrical circuits. Analogies are given for beams in bending and torsion with static loads and in vibrational motion.
Date: September 1952
Creator: Benscoter, Stanley U. & MacNeal, Richard H.
System: The UNT Digital Library
Equivalent-Plate Theory for a Straight Multicell Wing (open access)

Equivalent-Plate Theory for a Straight Multicell Wing

"A structural theory is developed for the analysis of thin multicell wings with straight spars and perpendicular ribs. The analysis is intended to be suitable for supersonic wings of low aspect ratio. Deflections due to shearing strains are taken into account" (p. 1).
Date: September 1952
Creator: Benscoter, Stanley U. & MacNeal, Richard H.
System: The UNT Digital Library
Effects of solvents in improving boundary lubrication of steel by silicones (open access)

Effects of solvents in improving boundary lubrication of steel by silicones

Report presenting a study to establish the effect of solvents on boundary lubrication by silicones. Boundary-lubrication data were obtained which are considered substantiating evidence for a hypothesis that, in solutions of solvents blended with silicones, the silicones form a closely packed and oriented absorbed film on ferrous surfaces. Results regarding room-temperature lubrication experiments, elevated-temperature lubrication experiments, low-temperature physical behavior, and effect of conventional lubrication additive are provided.
Date: September 1952
Creator: Murray, S. F. & Johnson, Robert L.
System: The UNT Digital Library
Equations, Tables, and Figures for Use in the Analysis of Helium Flow at Supersonic and Hypersonic Speeds (open access)

Equations, Tables, and Figures for Use in the Analysis of Helium Flow at Supersonic and Hypersonic Speeds

Report presenting equations, tables, and figures for use in the analysis of helium flow at supersonic and hypersonic speeds. Tables are provided for useful dimensionless ratios for continuous one-dimensional flow and normal-shock waves as functions of Mach number. The oblique-shock characteristics of wedges and cones in helium at various Mach numbers are also presented.
Date: September 1957
Creator: Mueller, James N.
System: The UNT Digital Library
Effects of finite span on the section characteristics of two 45 degree sweptback wings of aspect ratio 6 (open access)

Effects of finite span on the section characteristics of two 45 degree sweptback wings of aspect ratio 6

Report presenting a study of the finite-span effects on the local loading characteristics of two sweptback wings at low speed in order to provide some information about the usefulness of two-dimensional section data and span-loading theory for determining the section characteristics of a swept wing. At low values of lift coefficient, the finite-span effects were restricted to regions of the wing close to the root and tip. Results regarding the local pressure-distribution comparisons, local lift-curve comparisons, and evaluation of surface-loading procedure are provided.
Date: September 1953
Creator: Hunton, Lynn W.
System: The UNT Digital Library
Linearized potential theory of propeller induction in a compressible flow (open access)

Linearized potential theory of propeller induction in a compressible flow

Report presenting the potential of the linearized flow for a lifting-line propeller of arbitrary circulation distribution at subsonic advance as derived in cylindrical harmonics. From the potential the induced angle at the lifting line is obtained.
Date: September 1953
Creator: Davidson, Robert E.
System: The UNT Digital Library
Velocity potential and air forces associated with a triangular wing in supersonic flow, with subsonic leading edges, and deforming harmonically according to a general quadratic equation (open access)

Velocity potential and air forces associated with a triangular wing in supersonic flow, with subsonic leading edges, and deforming harmonically according to a general quadratic equation

Report presenting the velocity potential for a triangular wing with subsonic leading edges experiencing harmonic deformations in supersonic flow. The oscillations considered are such that the amplitude of wing distortion can be represented by a general quadratic expression for a surface.
Date: September 1953
Creator: Watkins, Charles E. & Berman, Julian H.
System: The UNT Digital Library
Procedure for calculating flutter at high supersonic speed including camber deflections, and comparison with experimental results (open access)

Procedure for calculating flutter at high supersonic speed including camber deflections, and comparison with experimental results

Report presenting a method that can be used at high supersonic Mach numbers for calculating the flutter speed of wings with camber in their deflection modes. It is used to calculate the flutter speed of some wings that had been tested at Mach numbers of 1.3 and 3.0. Theoretical comparisons of the tested wings are also provided.
Date: September 1958
Creator: Morgan, Homer G.; Huckel, Vera & Runyan, Harry L.
System: The UNT Digital Library
Experimental investigation of axial and normal force characteristics of skewed nozzles (open access)

Experimental investigation of axial and normal force characteristics of skewed nozzles

Report presenting an investigation of normal forces produced by several skewed nozzles and a series of ejectors with skewed shrouds discharging into quiescent air as conducted with cold air at jet total-pressure ratios up to 6.5. Nozzles were terminated at angles of 30 degrees, 45 degrees, 60 degrees, and 75 degrees relative to the normal plane. Results regarding basic data, effect of skew angle and indentation, and effect of a skewed shroud are provided.
Date: September 1958
Creator: Carter, David J., Jr. & Vick, Allen R.
System: The UNT Digital Library
An investigation of some phenomena relating to aural detection of airplanes (open access)

An investigation of some phenomena relating to aural detection of airplanes

Report presenting an investigation to determine the effect of modifications made in the propulsion system of a single-engine airplane to substantially reduce its external noise, and, thereby, to evaluate the significance of the external noise level of an airplane with regard to the problem of its detection by ground observers.
Date: September 1958
Creator: Hubbard, Harvey H. & Maglieri, Domenic J.
System: The UNT Digital Library