Equations and Charts for the Rapid Estimation of Hinge-Moment and Effectiveness Parameters for Trailing-Edge Controls Having Leading and Trailing Edges Swept Ahead of the Mach Lines (open access)

Equations and Charts for the Rapid Estimation of Hinge-Moment and Effectiveness Parameters for Trailing-Edge Controls Having Leading and Trailing Edges Swept Ahead of the Mach Lines

"Existing conical-flow solutions have been used to calculate the hinge-moments and effectiveness parameters of trailing-edge controls having leading and trailing edges swept ahead of the Mach lines and having streamwise root and tip chords. Equations and detailed charts are presented for the rapid estimation of these parameters. Also included is an approximate method by which these parameters may be corrected for airfoil-section thickness" (p. 937).
Date: September 8, 1950
Creator: Goin, Kennith L.
System: The UNT Digital Library
A comparison of theory and experiment for high-speed free-molecule flow (open access)

A comparison of theory and experiment for high-speed free-molecule flow

A comparison is made of free-molecule-flow theory with the results of wind-tunnel tests performed to determine the drag and temperature-rise characteristics of a transverse circular cylinder. The measured values of the cylinder center-point temperature confirmed the salient point of the heat-transfer analysis which was the prediction that an insulated cylinder would attain a temperature higher than the stagnation temperature of the stream. Good agreement was obtained between the theoretical and the experimental values for the drag coefficient.
Date: September 12, 1950
Creator: Stalder, Jackson R.; Goodwin, Glen & Creager, Marcus O.
System: The UNT Digital Library
A numerical method for the stress analysis of stiffened-shell structures under nonuniform temperature distributions (open access)

A numerical method for the stress analysis of stiffened-shell structures under nonuniform temperature distributions

A numerical method is presented for the stress analysis of stiffened-shell structures of arbitrary cross section under nonuniform temperature distributions. The method is based on a previously published procedure that is extended to include temperature effects and multicell construction. The application of the method to practical problems is discussed and an illustrative analysis is presented of a two-cell box beam under the combined action of vertical loads and a nonuniform temperature distribution.
Date: September 12, 1950
Creator: Heldenfels, Richard R.
System: The UNT Digital Library
Investigation of Downwash, Sidewash, and Mach Number Distribution Behind a Rectangular Wing at a Mach Number of 2.41 (open access)

Investigation of Downwash, Sidewash, and Mach Number Distribution Behind a Rectangular Wing at a Mach Number of 2.41

"An investigation of the nature of the flow field behind a rectangular wing of circular arc cross section has been conducted in the Langley 9-inch supersonic tunnel. Pitot- and static-pressure surveys covering a region of flow behind the wing have been made together with detailed pitot surveys throughout the region of the wake. In addition, the flow direction has been measured by means of a weathercocking vane. Theoretical calculations have been made to obtain the variation of both downwash and sidewash with angle of attack by using the superposition method of Lagerstrom, Graham, and Grosslight" (p. 1).
Date: September 14, 1950
Creator: Adamson, David & Boatright, William B.
System: The UNT Digital Library
Some Features of Artificially Thickened Fully Developed Turbulent Boundary Layers with Zero Pressure Gradient (open access)

Some Features of Artificially Thickened Fully Developed Turbulent Boundary Layers with Zero Pressure Gradient

Report gives an account of an investigation conducted to determine the feasibility of artificially thickening a turbulent boundary layer on a flat plate. A description is given of several methods used to thicken artificially the boundary layer. It is shown that it is possible to do substantial thickening and obtain a fully developed turbulent boundary layer, which is free from any distortions introduced by the thickening process, and, as such, is a suitable medium for fundamental research.
Date: September 15, 1950
Creator: Klebanoff, P. S. & Diehl, Z. W.
System: The UNT Digital Library
Some Effects of Nonlinear Variation in the Directional-Stability and Damping-in-Yawing Derivatives on the Lateral Stability of an Airplane (open access)

Some Effects of Nonlinear Variation in the Directional-Stability and Damping-in-Yawing Derivatives on the Lateral Stability of an Airplane

"A theoretical investigation has been made to determine the effect of nonlinear stability derivatives on the lateral stability of an airplane. Motions were calculated on the assumption that the directional-stability and the damping-in-yawing derivatives are functions of the angle of sideslip. The application of the Laplace transform to the calculation of an airplane motion when certain types of nonlinear derivatives are present is described in detail" (p. 1009).
Date: September 19, 1950
Creator: Sternfield, Leonard
System: The UNT Digital Library
Theoretical symmetric span loading due to flap deflection for wings of arbitrary plan form at subsonic speeds (open access)

Theoretical symmetric span loading due to flap deflection for wings of arbitrary plan form at subsonic speeds

From Summary: "A simplified lifting-surface theory is applied to the problem of evaluating span loading due to flap deflection for arbitrary wing plan forms. With the resulting procedure, the effects of flap deflection on the span loading and associated aerodynamic characteristics can be easily computed for any wing which is symmetrical about the root chord and which has a straight quarter-chord line over the wing semispan. The effects of compressibility and spanwise variation of section lift-curve slope are taken into account by the procedure. The method presented can also be used to calculate the downwash in the vertical center of the wake of a wing which has arbitrary spanwise loading."
Date: September 22, 1950
Creator: DeYoung, John
System: The UNT Digital Library
Supersonic Flow Around Circular Cones at Angles of Attack (open access)

Supersonic Flow Around Circular Cones at Angles of Attack

The properties of conical flow without axial symmetry are analyzed. The flow around cones of circular cross section at small angles of attack is determined by correctly considering the effect of the entropy gradients in the flow.
Date: September 26, 1950
Creator: Ferri, Antonio
System: The UNT Digital Library
Calculations on the forces and moments for an oscillating wing-aileron combination in two-dimensional potential flow at sonic speed (open access)

Calculations on the forces and moments for an oscillating wing-aileron combination in two-dimensional potential flow at sonic speed

From Summary: "The linearized theory for compressible unsteady flow is used, as suggested in recent contributions to the subject, to obtain the velocity potential and the lift and moment for a thin harmonically oscillating, two-dimensional wing-aileron combination moving at sonic speed. The velocity potential is derived by considering the sonic case as the limit of the linearized supersonic theory. From the velocity potential explicit expressions for the lift and moment are developed for vertical translation and pitching of the wing and rotation of the aileron. The sonic results are compared and found to be consistent with previously obtained subsonic and supersonic results. Several figures are presented showing the variation of lift and moment with reduced frequency and Mach number and the influence of Mach number on some cases of bending-torsion flutter."
Date: September 4, 1951
Creator: Nelson, Herbert C. & Berman, Julian H.
System: The UNT Digital Library
A study of elastic and plastic stress concentration factors due to notches and fillets in flat plates (open access)

A study of elastic and plastic stress concentration factors due to notches and fillets in flat plates

Six large 24s-t3 aluminum-alloy-sheet specimens containing various notches or fillets were tested in tension to determine their stress concentration factors in both the elastic and plastic ranges. The elastic stress concentration factors were found to be slightly higher than those calculated by Neuber's method and those obtained photoelastically by Frocht. The results showed further that the stress concentration factor decreases as strains at the discontinuity enter the plastic range. A generalization of Stowell's relation for the plastic stress concentration factor at a circular hole in an infinite plate was applied to the specimen shapes tested and gave good agreement with test results.
Date: September 7, 1951
Creator: Hardrath, Herbert F. & Ohman, Lachlan
System: The UNT Digital Library
A flight evaluation of the longitudinal stability characteristics associated with the pitch-up of a swept-wing airplane in maneuvering flight at transonic speeds (open access)

A flight evaluation of the longitudinal stability characteristics associated with the pitch-up of a swept-wing airplane in maneuvering flight at transonic speeds

This report presents the results of flight measurements of longitudinal stability and control characteristics made on a swept-wing jet aircraft to determine the origin of the pitch-up encountered in maneuvering flight at transonic speeds. For this purpose measurements were made of elevator angle, tail angle of attack, and wing-fuselage pitching moments (obtained from measurements of the balancing tail loads).
Date: September 12, 1951
Creator: Anderson, Seth B. & Bray, Richard S.
System: The UNT Digital Library
Impingement of Cloud Droplets on a Cylinder and Procedure for Measuring Liquid-Water Content and Droplet Sizes in Supercooled Clouds by Rotating Multicylinder Method (open access)

Impingement of Cloud Droplets on a Cylinder and Procedure for Measuring Liquid-Water Content and Droplet Sizes in Supercooled Clouds by Rotating Multicylinder Method

"Evaluation of the rotating multicylinder method for the measurement of droplet-size distribution, volume-median droplet size, and liquid-water content in clouds showed that small uncertainties in the basic data eliminate the distinction between different cloud droplet-size distributions and are a source of large errors in the determination of the droplet size. Calculations of the trajectories of cloud droplets in incompressible and compressible flow fields around a cylinder were performed on a mechanical analog constructed for the study of the trajectories of droplets around aerodynamic bodies" (p. 1).
Date: September 5, 1952
Creator: Brun, R. J.; Lewis, W.; Perkins, P. J. & Serafini, J. S.
System: The UNT Digital Library
The dynamic-response characteristics of a 35 degree swept-wing airplane as determined from flight measurements (open access)

The dynamic-response characteristics of a 35 degree swept-wing airplane as determined from flight measurements

From Summary: "The longitudinal and lateral-directional dynamic-response characteristics of a 35 degree swept-wing fighter-type airplane determined from flight measurements are presented and compared with predictions based on theoretical studies and wind-tunnel data. Flights were made at an altitude of 35,000 feet covering the Mach number range of 0.50 to 1.04. A limited amount of lateral-directional data were also obtained at 10,000 feet. The flight consisted essentially of recording transient responses to pilot-applied pulsed motions of each of the three primary control surfaces. These transient data were converted into frequency-response form by means of the Fourier transformation and compared with predicted responses calculated from the basic equations. Experimentally determined transfer functions were used for the evaluation of the stability derivatives that have the greatest effect on the dynamic response of the airplane. The values of these derivatives, in most cases, agreed favorably with predictions over the Mach number range of the test."
Date: September 17, 1952
Creator: Triplett, William C.; Brown, Stuart C. & Smith, G. Allan
System: The UNT Digital Library
Convection of a pattern of vorticity through a shock wave (open access)

Convection of a pattern of vorticity through a shock wave

An arbitrary weak spatial distribution of vorticity can be represented in terms of plane sinusoidal shear waves of all orientations and wave lengths (Fourier integral). The analysis treats the passage of a single representative weak shear wave through a plane shock and shows refraction and modification of the shear wave with simultaneous generation of an acoustically intense sound wave. Applications to turbulence and to noise in supersonic wind tunnels are indicated.
Date: September 26, 1952
Creator: Ribner, H. S.
System: The UNT Digital Library
A Study of the Application of Power-Spectral Methods of Generalized Harmonic Analysis to Gust Loads on Airplanes (open access)

A Study of the Application of Power-Spectral Methods of Generalized Harmonic Analysis to Gust Loads on Airplanes

"The applicability of some results from the theory of generalized harmonic analysis (or power-spectral analysis) to the analysis of gust loads on airplanes in continuous rough air is examined. The general relations for linear systems between power spectrums of a random input disturbance and an output response are used to relate the spectrum of airplane load in rough air to the spectrum of atmospheric gust velocity. The power spectrum of loads is shown to provide a measure of the load intensity in terms of the standard deviation (root mean square) of the load distribution for an airplane in flight through continuous rough air" (p. 371).
Date: September 29, 1952
Creator: Press, Harry & Mazelsky, Bernard
System: The UNT Digital Library
Flight Determination of Drag of Normal-Shock Nose Inlets With Various Cowling Profiles at Mach Numbers From 0.9 to 1.5 (open access)

Flight Determination of Drag of Normal-Shock Nose Inlets With Various Cowling Profiles at Mach Numbers From 0.9 to 1.5

External-drag data are presented for normal-shock nose inlets with NACA 1-series, parabolic, and conic cowling profiles. The tests were made at an angle of attack of 0 degrees by using rocket-propelled models in free flight at Mach numbers from 0.9 to 1.5. The Reynolds number based on body maximum diameter varied from 2.5 x 10 sup 6 to 5.5 x 10 sup 6.
Date: September 8, 1953
Creator: Sears, R. I.; Merlet, C. F. & Putland, L. W.
System: The UNT Digital Library
Theoretical combustion performance of several high-energy fuels for ramjet engines (open access)

Theoretical combustion performance of several high-energy fuels for ramjet engines

An analytical evaluation of the air and fuel specific-impulse characteristics of magnesium, magnesium octene-1 slurries, aluminum, aluminum octene-1 slurries, boron, boron octene-1 slurries, carbon, hydrogen, alpha-methylnaphthalene, diborane, pentaborane, and octene-1 is presented. While chemical equilibrium was assumed in the combustion process, the expansion was assumed to occur at fixed composition.
Date: September 14, 1953
Creator: Tower, Leonard K.; Breitwieser, Roland & Gammon, Benson E.
System: The UNT Digital Library
A wind-tunnel test technique for measuring the dynamic rotary stability derivatives at subsonic and supersonic speeds (open access)

A wind-tunnel test technique for measuring the dynamic rotary stability derivatives at subsonic and supersonic speeds

"A method is described for measuring the dynamic stability derivatives of a model airplane in a wind tunnel. The characteristic features of this system are that single-degree-of-freedom oscillations were used to obtain combinations of rolling, yawing and pitching motions; that the oscillations were excited and controlled by velocity feedback which permitted operation under conditions unfavorable for more conventional types of oscillatory testing; and that data processing was greatly simplified by using analog computer elements in the strain-gage circuitry. A small number of experimental data are included to illustrate the general scope of results obtainable with this system" (p. 1).
Date: September 20, 1954
Creator: Beam, Benjamin H.
System: The UNT Digital Library
Investigation of the compressive strength and creep lifetime of 2024-T3 aluminum-alloy plates at elevated temperatures (open access)

Investigation of the compressive strength and creep lifetime of 2024-T3 aluminum-alloy plates at elevated temperatures

The results of elevated-temperature compressive strength and creep tests of 2024-t3 (formerly 24s-t3) aluminum alloy plates supported in v-grooves are presented. The strength-test results indicate that a relation previously developed for predicting plate compressive strength for plates of all materials at room temperature is also satisfactory for determining elevated-temperature strength. Creep-lifetime results are presented for plates in the form of master creep-lifetime curves by using a time-temperature parameter that is convenient for summarizing tensile creep-rupture data. A comparison is made between tensile and compressive creep lifetime for the plates and a method that made use of isochronous stress-strain curves for predicting plate-creep failure stresses is investigated.
Date: September 8, 1955
Creator: Mathauser, Eldon E. & Deveikis, William D.
System: The UNT Digital Library
A method for simulating the atmospheric entry of long-range ballistic missiles (open access)

A method for simulating the atmospheric entry of long-range ballistic missiles

From Summary: "It is demonstrated with the aid of similitude arguments that a model launched from a hypervelocity gun upstream through a special supersonic nozzle should experience aerodynamic heating and resulting thermal stresses like those encountered by a long-range ballistic missile entering the earth's atmosphere. This demonstration hinges on the requirements that model and missile be geometrically similar and made of the same material, and that they have the same flight speed and Reynolds number (based on conditions just outside the boundary layer) at corresponding points in their trajectories. The hypervelocity gun provides the model with the required initial speed, while the nozzle scales the atmosphere, in terms of density variation, to provide the model with speeds and Reynolds numbers over its entire trajectory."
Date: September 15, 1955
Creator: Eggers, A. J., Jr.
System: The UNT Digital Library
Average Properties of Compressible Laminar Boundary Layer on Flat Plate With Unsteady Flight Velocity (open access)

Average Properties of Compressible Laminar Boundary Layer on Flat Plate With Unsteady Flight Velocity

The time-average characteristics of boundary layers over a flat plate in nearly quasi-steady flow are determined. The plate may be either insulated or isothermal. The time averages are found without specifying the plate velocity explicitly except that it is positive and has an average value.
Date: September 5, 1956
Creator: Moore, Franklin K. & Ostrach, Simon
System: The UNT Digital Library
Theoretical calculation of the power spectra of the rolling and yawing moments on a wing in random turbulence (open access)

Theoretical calculation of the power spectra of the rolling and yawing moments on a wing in random turbulence

The correlation functions and power spectra of the rolling and yawing moments on an airplane wing due to the three components of continuous random turbulence are calculated. The rolling moments to the longitudinal (horizontal) and normal (vertical) components depend on the spanwise distributions of instantaneous gust intensity, which are taken into account by using the inherent properties of symmetry of isotropic turbulence. The results consist of expressions for correlation functions or spectra of the rolling moment in terms of the point correlation functions of the two components of turbulence.
Date: September 6, 1956
Creator: Eggleston, John M. & Diederich, Franklin W.
System: The UNT Digital Library
Theoretical analysis of total-pressure loss and airflow distribution for tubular turbojet combustors with constant annulus and liner cross-sectional areas (open access)

Theoretical analysis of total-pressure loss and airflow distribution for tubular turbojet combustors with constant annulus and liner cross-sectional areas

"Compressible and incompressible flow calculations were made of the combustor total-pressure-loss coefficient and liner airflow distribution for tubular turbojet combustors having constant annulus and liner cross-sectional areas along the combustor axis. Information on static and total pressure distribution and liner air-jet entrance angles along the length of the combustor was obtained as an intermediate step in the calculations. The calculations include the effects of heat release, annulus wall friction, and variation in discharge coefficients of the liner wall openings along the combustor" (p. 899).
Date: September 17, 1956
Creator: Graves, Charles C. & Grobman, Jack S.
System: The UNT Digital Library