UNT Libraries Government Documents Department - 20 Matching Results

Search Results

Results: 1 - 20
open access

Amplitude of Supersonic Diffuser Flow Pulsations

Description: From Introduction: "This report, prepared at the NACA Lewis laboratory, presents a theoretical evaluation of the variables which govern pulsation amplitude for the cold-flow engine."
Date: October 1955
Creator: Sterbentz, William H. & Davids, Joseph
open access

An analysis of acceleration, airspeed, and gust-velocity data from one type of four-engine transport airplane operated over two domestic routes

Description: From Introduction: "As part of a continuing study of the gust and load histories for transport airplanes (see, for example, refs. 1 and 2), samples of VGH records have been obtained from two four-engine commercial transport airplanes. The data samples represent 839 and 1,080 flight hours of operation on two transcontinental routes and cover operations up to an altitude of 25,000 feet."
Date: October 1955
Creator: Copp, Martin R. & Coleman, Thomas L.
open access

An Approximate Solution for Axially Symmetric Flow Over a Cone With an Attached Shock Wave

Description: "It is shown that the streamlines in an angular neighborhood of the surface of an unyawed circular cone with an attached shock wave are, to a first approximation, portions of hyperbolas. This fact is used as a basis for the development of an approximate solution in which the shock-wave orientation and the flow field behind the shock wave are given explicitly in terms of the free-stream Mach number, the vertex angle of the body cone, and the ratio of specific heats of the gas. The approximate so… more
Date: October 1955
Creator: Hord, Richard A.
open access

Averaging of Periodic Pressure Pulsations by a Total-Pressure Probe

Description: Note presenting information on the average pressure indicated by a total-pressure probe subjected to a stagnation pressure that alternates periodically between two constant values. Calculated and experimental data are in good agreement and errors are reduced when the probe design is such as to ensure laminar-flow pulsations in the probe at all times.
Date: October 1955
Creator: Johnson, R. C.
open access

Burning Velocities of Various Premixed Turbulent Propane Flames on Open Burners

Description: Note presenting the measurement of turbulent burning velocities for premixed propane flames at room temperature and atmospheric pressure. The measurements were made for systems of various laminar burning velocities, densities, and viscosities. Experimental results and comparison with previous work are provided.
Date: October 1955
Creator: Wagner, Paul
open access

Calculated spanwise lift distributions and aerodynamic influence coefficients for swept wings in subsonic flow

Description: Report presenting spanwise lift distribution calculations for 61 swept wings with various aspect ratios and taper ratios and with a variety of angle-of-attack or twist distributions, including flap and aileron deflections, by means of the Weissinger method with eight control points on the semispan. Also calculated were the aerodynamic influence coefficients which pertain to a certain definite set of stations along the span.
Date: October 1955
Creator: Diederich, Franklin W. & Zlotnick, Martin
open access

Comparison Between Theoretical and Experimental Stresses in Circular Semimonocoque Cylinders With Rectangular Cutouts

Description: "Comparisons are made between a theory for calculating stresses about rectangular cutouts in circular cylinders of semimonocoque construction published in NACA-TN-3200 and previously published NACA experimental data. The comparisons include stresses in the stringers and shear stresses in the center of the shear panels in the neighborhood of the cutout. The theory takes into account the bending flexibility of the rings in the structure, and this factor is found to be important in the calculation… more
Date: October 1955
Creator: McComb, Harvey G., Jr. & Low, Emmet F., Jr.
open access

Effect of exhaust-nozzle ejectors on turbojet noise generation

Description: From Summary: "Engine noise levels and jet-velocity profiles have been obtained with several turbojet exhaust-nozzle ejectors. An insignificant reduction in total sound power was realized. At subsonic nozzle pressure ratios, total sound power from exhaust-nozzle ejectors or bypass exit configurations can be calculated from primary-jet parameters only."
Date: October 1955
Creator: North, Warren J. & Coles, Willard D.
open access

An experimental comparison of the Lagrangian and Eulerian correlation coefficients in homogeneous isotropic turbulence

Description: Report presenting an experimental comparison between the Langrangian and Eulerian correlation coefficients in the homogeneous, isotropic central core of a turbulent pipe flow. They had similar shapes related by a linear proportionality between their time and space coordinates. Results regarding the general stream conditions, lateral turbulence-intensity measurements, longitudinal turbulence-intensity measurements, radial and axial measurements of the Eulerian correlation coefficient, and turbul… more
Date: October 1955
Creator: Mickelsen, William R.
open access

Influence of Shear Deformation of the Cross Section on Torsional Frequencies of Box Beams

Description: "An exact analysis has been carried out on the torsional vibrations of a four-flange box beam with cross sections which can change shape because the stiffness of the bulkheads is finite. The effect of shear deformation of the cross section on the torsional frequencies is illustrated by numerical calculations. An approximate method for quickly estimating the effects of bulkhead shear stiffness on the torsional frequencies of box beams has been devised" (p. 1).
Date: October 1955
Creator: Kruszewski, Edwin T. & Davenport, William W.
open access

Investigation of the Vibrations of a Hollow Thin-Walled Rectangular Beam

Description: "Experimental modes and frequencies of an unstiffened hollow beam of rectangular cross section are presented, and comparisons are made between experimental and theoretical frequencies. Theories based on rigid cross sections were found to be sufficiently accurate to predict the frequencies of only the lowest three bending modes. For the higher bending modes and all the torsional modes it was necessary to include the effects of cross-sectional distortions in the calculations" (p .1).
Date: October 1955
Creator: Kordes, Eldon E. & Kruszewski, Edwin T.
open access

Investigation of the Vibrations of a Hollow Thin-Walled Rectangular Beam

Description: Experimental modes and frequencies of an unstiffened hollow beam of rectangular cross section are presented, and comparisons are made between experimental and theoretical frequencies. Theories based on rigid cross sections were found to be sufficiently accurate to predict the frequencies of only the lowest three bending modes. For the higher bending modes and all the torsional modes it was necessary to include the effects of cross-sectional distortions in the calculations.
Date: October 1955
Creator: Kordes, Eldon E. & Kruszewski, Edwin T.
open access

Low-speed static lateral and rolling stability characteristics of a series of configuration composed of intersecting triangular plan-form surfaces

Description: Report presenting the static lateral and rolling stability derivatives of a series of cruciform, inverted T-, V-, and Y-configurations composed of low-aspect-ratio triangular surfaces at low speed in the rolling-flow test section. Comparisons have been made to indicate the extent of agreement between experiment and existing theory. Results regarding sideslip characteristics and steady rolling characteristics are provided.
Date: October 1955
Creator: Thomas, David F., Jr.
open access

Pilot's loss of orientation in inverted spins

Description: Note presenting a discussion of the nature of inverted spins, the optimum control technique for recovery, and some of the apparent reasons for a pilot's loss of orientation, which can lead to accidents. Results regarding testing in the free-spinning-tunnel, airplane experiences, and a description of a new spinning simulator rig designed to investigation the orientation loss problem are provided.
Date: October 1955
Creator: Scher, Stanley H.
open access

Some effects of system nonlinearities in the problem of aircraft flutter

Description: Report presenting the results of a preliminary investigation of the effect of nonlinear structural terms on the flutter of a two-degree-of-freedom system. The three types of nonlinearities investigated were a flat spot, hysteresis, and a cubic spring. The results indicate that sometimes nonlinear effects can be large and destabilizing.
Date: October 1955
Creator: Woolston, Donald S.; Runyan, Harry L. & Byrdsong, Thomas A.
open access

Sound Propagation Into the Shadow Zone in a Temperature-Stratified Atmosphere Above a Plane Boundary

Description: Note presenting an investigation of the sound field about a point source over a plane boundary in the presence of a vertical temperature gradient, which represents one phase of a general program of research in atmospheric acoustics. In this report, geometrical ray acoustics is employed to derive the ray paths and intensity distribution about a source located in a uniformly stratified medium. Results indicate that the existence of a temperature gradient, which leads only to a simple refraction o… more
Date: October 1955
Creator: Pridmore-Brown, David C. & Ingard, Uno
open access

Study of Screeching Combustion in a 6-Inch Simulated Afterburner

Description: Report presenting an investigation to develop screech instrumentation and to study the mechanism of screech in a 6-inch-diameter simulated afterburner. Probe microphones have been developed to measure frequency, relative amplitude, and relative phasing of the pressure oscillations at positions in a screeching combustor.
Date: October 1955
Creator: Blackshear, Perry L.; Rayle, Warren D. & Tower, Leonard K.
open access

Summary of derived gust velocities obtained from measurements within thunderstorms

Description: Report presenting the available data on the derived gust velocities in thunderstorms for altitudes up to 34,000 feet. The derived gust velocities were obtained from the previously evaluated effective gust velocities through use of a conversion factor that is a function of airplane characteristics and altitude.
Date: October 1955
Creator: Tolefson, H. B.
open access

A Universal Column Formula for Load at Which Yielding Starts

Description: "An analysis is presented of the load at which yielding first occurs in actual columns, taking adequately into account all the factors which have an important effect upon this load. These factors include initial defects and the yielding limit of materials. Extensive tests were made to verify the assumed relation between the magnitudes of the defects and the known properties of columns. The results are expressed as a formula or chart applicable to all situations" (p. 1).
Date: October 1955
Creator: Donnell, L. H. & Tsien, V. C.
Back to Top of Screen