A study of the zero-lift drag-rise characteristics of wing-body combinations near the speed of sound (open access)

A study of the zero-lift drag-rise characteristics of wing-body combinations near the speed of sound

"Comparisons have been made of the shock phenomena and drag-rise increments for representative wing and central-body combinations with those for bodies of revolution having the same axial developments of cross-sectional areas normal to the airstream. On the basis of these comparisons, it is concluded that near the speed of sound the zero-lift drag rise of a low-aspect-ratio thin-wing and body combination is primarily dependent on the axial development of the cross-sectional areas normal to the airstream. It follows that the drag rise for any such configuration is approximately the same as that for any other with the same development of cross-sectional areas" (p. 519).
Date: August 1, 1952
Creator: Whitcomb, Richard T.
System: The UNT Digital Library
Hydrocarbon and nonhydrocarbon derivatives of cyclopropane (open access)

Hydrocarbon and nonhydrocarbon derivatives of cyclopropane

The methods used to prepare and purify 19 hydrocarbon derivatives of cyclopropane are discussed. Of these hydrocarbons, 13 were synthesized for the first time. In addition to the hydrocarbons, six cyclopropylcarbinols, five alkyl cyclopropyl ketones, three cyclopropyl chlorides, and one cyclopropanedicarboxylate were prepared as synthesis intermediates. The melting points, boiling points, refractive indices, densities, and, in some instances, heats of combustion of both the hydrocarbon and nonhydrocarbon derivatives of cyclopropane were determined. These data and the infrared spectrum of each of the 34 cyclopropane compounds are presented in this report. The infrared absorption bands characteristic of the cyclopropyl ring are discussed, and some observations are made on the contribution of the cyclopropyl ring to the molecular refractions of cyclopropane compounds.
Date: August 15, 1952
Creator: Slabey, Vernon A.; Wise, Paul H. & Gibbons, Louis C.
System: The UNT Digital Library
Theoretical study of the transonic lift of a double-wedge profile with detached bow wave (open access)

Theoretical study of the transonic lift of a double-wedge profile with detached bow wave

"A theoretical study is described of the aerodynamic characteristics at small angle of attack of a thin, double-wedge profile in the range of supersonic flight speed in which the bow wave is detached. The analysis is carried out within the framework of the transonic (nonlinear) small-disturbance theory, and the effects of angle of attack are regarded as a small perturbation on the flow previously calculated at zero angle. The mixed flow about the front half of the profile is calculated by relaxation solution of a suitably defined boundary-value problem for transonic small-disturbance equation in the hodograph plane (i.e., the Tricomi equation)" (p. 547).
Date: August 1, 1952
Creator: Vincenti, Walter G. & Wagoner, Cleo B.
System: The UNT Digital Library
A unified two-dimensional approach to the calculation of three-dimensional hypersonic flows, with application to bodies of revolution (open access)

A unified two-dimensional approach to the calculation of three-dimensional hypersonic flows, with application to bodies of revolution

A procedure for calculating three-dimensional steady and nonsteady supersonic flows with the method of characteristics is developed and discussed. An approximate method is deduced from the characteristics method and shown to be of practical value at high supersonic speeds.
Date: August 15, 1952
Creator: Eggers, A. J., Jr. & Savin, Raymond C.
System: The UNT Digital Library
Investigation of the drag of various axially symmetric nose shapes of fineness ratio 3 for Mach numbers from 1.24 to 7.4 (open access)

Investigation of the drag of various axially symmetric nose shapes of fineness ratio 3 for Mach numbers from 1.24 to 7.4

Experimental drag measurements at zero angle of attack for various theoretical minimum drag nose shapes, hemispherically blunted cones, and other more common profiles of fineness ratios of about 3 are compared with theoretical results for a Mach number and Reynolds number range of 1.24 to 7.4 and 1.0 x 10 to the 6th power to 7.5 x 10 to the 6th power (based on body length), respectively. The results of experimental pressure-distribution measurements are used for the development of an empirical expression for predicting the pressure drag of hemispherically blunted cones.
Date: August 28, 1952
Creator: Perkins, Edward W.; Jorgensen, Leland H. & Sommer, Simon C.
System: The UNT Digital Library
Calibration of strain-gage installations in aircraft structures for the measurement of flight loads (open access)

Calibration of strain-gage installations in aircraft structures for the measurement of flight loads

"A general method has been developed for calibrating strain-gage installations in aircraft structures, which permits the measurement in flight of the shear or lift, the bending moment, and the torque or pitching moment on the principal lifting or control surfaces. Although the stress in structural members may not be a simple function of the three loads of interest, a straightforward procedure is given for numerically combining the outputs of several bridges in such a way that the loads may be obtained. Extensions of the basic procedure by means of electrical combination of the strain-gage bridges are described which permit compromises between strain-gage installation time, availability of recording instruments, and data reduction time" (p. 1).
Date: August 12, 1952
Creator: Skopinski, T. H.; Aiken, William S., Jr. & Huston, Wilber B.
System: The UNT Digital Library
The Normal Component of the Induced Velocity in the Vicinity of a Lifting Rotor and Some Examples of Its Application (open access)

The Normal Component of the Induced Velocity in the Vicinity of a Lifting Rotor and Some Examples of Its Application

"Paper presents a practical method for computing the approximate values of the normal component of the induced velocity at points in the flow field of a lifting rotor. Tables and graphs of the relative magnitudes of the normal component of the induced velocity are given for selected points in the longitudinal plane of symmetry of the rotor and on the lateral rotor axis. A method is also presented for utilizing the tables and graphs to determine the interference induced velocities arising from the second rotor of a tandem or side-by-side-rotor helicopter and the induced flow angle at a horizontal tail plane" (p. 1).
Date: August 11, 1952
Creator: Castles, Walter, Jr. & De Leeuw, Jacob Henri
System: The UNT Digital Library
Mechanism of Start and Development of Aircraft Crash Fires (open access)

Mechanism of Start and Development of Aircraft Crash Fires

"Full-scale aircraft crashes were made to investigate the mechanism of the start and development of aircraft crash fires. The results are discussed herein. This investigation revealed the characteristics of the ignition sources, the manner in which the combustibles spread, the mechanism of the union of the combustibles and ignition sources, and the pertinent factors governing the development of a crash fire as observed in this program" (p. 547).
Date: August 1, 1952
Creator: Pinkel, I. Irving; Preston, G. Merritt & Pesman, Gerard J.
System: The UNT Digital Library