On optical imaging through aircraft turbulent boundary layers

Optical resolution quality as affected by aircraft turbulent boundary layers is analyzed. Wind-tunnel data was analyzed to obtained the variation of boundary layer turbulence scale length and mass density rms fluctuations with Mach number. The data gave good agreement with a mass density fluctuation turbulence spectrum that is either isotropic of orthogonally anisotropic. The data did not match an isotropic turbulence velocity spectrum which causes an anisotropic non-orthogonal mass density fluctuation spectrum. The results indicate that the average mass density rms fluctuation is about 10% of the maximum mass density across the boundary layer and that the transverse turbulence scale size is about 10% of the boundary layer thickness. The results indicate that the effect of the turbulent boundary layer is large angle scattering which decreases contrast but not resolution. Using extinction as a criteria the range of acceptable aircraft operating conditions are given

THE CHANGING POLITICAL ENVIRONMENT FOR TOBACCO -- IMPLICATIONS FOR SOUTHERN TOBACCO FARMERS, RURAL ECONOMIES, TAXPAYERS, AND CONSUMERS: DISCUSSION

This paper is a discussion of the Brown, Snell, and Tiller article. The economic accuracy, conciseness, and organization is noteworthy with the major strength being the analysis of the tobacco system with the absence of a Federal program. The base paper discusses economic consequences of the U.S. tobacco program, within-industry structural differences, and recent/potential future changes such as the buy-out, industry uncertainty, and the possibility of program elimination.price-support program, tobacco industry, tobacco program, Agricultural and Food Policy,

General Tobacco Policy Survey Questions from the Tobacco Baling Survey

Crop Production/Industries,

Experimental L-band SST satellite communications/surveillance terminal study. Volume 1 - Study summary

Study of design for experimental L band supersonic transport communications/surveillance termina

Tobacco Baling Survey

Crop Production/Industries,

A Photoelastic Study of Strain Waves Caused by Cavitation

Ultra-high-speed photoelastic techniques have been applied to a study of the transient stresses and strains in a photoelastic plastic when subject to cavitation. A photocell, used to detect the transient strains, indicated that the time duration of the strains was about 2 microseconds. Using an ultra-high-speed motion picture camera, ultrasonic cavitation bubbles have been photographed collapsing on the surface of a photoelastic specimen, and the resulting strain wave in the solid has been photographed. The dynamic properties of a photoelastic material have been obtained in order to permit quantitative interpretation of the transients. This has indicated that the stresses due to cavitation may be as high as 2.8 x 10^5 psi. The photoelastic plastic, CR-39, was found to exhibit strain birefringence, and its strain-optic constant was found to be independent of the rate of loading

An Intermediate Theory of Longitudinal Stress Waves in Bars

The expressions for kinetic and strain energy for longitudinal stress waves in a bar are considered, first in a one-dimensional model in which cross sections are assumed to remain plane, and stresses in the radial and circumferential direction are assumed to be zero. From this, an equation of motion is derived which is used to determine the speed of longitudinal sinusoidal stress waves as a function of wave length. Secondly, a simplified three-dimensional model is considered where the axial motion is a parabolic function of the radius, from which the speed of sinusoidal stress waves is derived. The derived expressions are compared with previously published solutions

Operating manual for coaxial injection combustion model

An operating manual for the coaxial injection combustion model (CICM) is presented as the final report for an eleven month effort designed to provide improvement, to verify, and to document the comprehensive computer program for analyzing the performance of thrust chamber operation with gas/liquid coaxial jet injection. The effort culminated in delivery of an operation FORTRAN IV computer program and associated documentation pertaining to the combustion conditions in the space shuttle main engine. The computer program is structured for compatibility with the standardized Joint Army-Navy-NASA-Air Force (JANNAF) performance evaluation procedure. Use of the CICM in conjunction with the JANNAF procedure allows the analysis of engine systems using coaxial gas/liquid injection