A second-order closure analysis of turbulent diffusion flames

A complete second-order closure computer program for the investigation of compressible, turbulent, reacting shear layers was developed. The equations for the means and the second order correlations were derived from the time-averaged Navier-Stokes equations and contain third order and higher order correlations, which have to be modeled in terms of the lower-order correlations to close the system of equations. In addition to fluid mechanical turbulence models and parameters used in previous studies of a variety of incompressible and compressible shear flows, a number of additional scalar correlations were modeled for chemically reacting flows, and a typical eddy model developed for the joint probability density function for all the scalars. The program which is capable of handling multi-species, multistep chemical reactions, was used to calculate nonreacting and reacting flows in a hydrogen-air diffusion flame

Contribution of combustion noise to overall rocket exhaust jet noise

Low frequency noise measurements of Saturn rocket engine, and combustion noise contribution to overall rocket exhaust jet nois

MOLECULAR SPECTRA PRODUCED BY COLLISION WITH METASTABLE NOBLE GAS ATOMS

Author Institution: Research Department, Grumman Aircraft Engineering CorporationExperimental studies have been conducted of the radiation emitted by diatomic molecules excited by collision with metastable noble gas atoms. Results indicate that under certain conditions the transfer of energy between the metastable atom and the molecule may be very efficient. The metastable levels of the noble gas atoms are populated through collisions with a collimated beam of high energy $(> 10 keV)$ electrons. The following molecular systems have been studied: argon-nitrogen, xenon-nitrogen, helium-nitrogen, and argon-carbonmonoxide. Results to date indicate that the transfer of energy is most efficient during a collisional exchange in which the total electron spin and internal energy are conserved. In addition, existing selection rules for the collisional transfer of energy do not predict some of the experimental results

SPECTRAL EMISSIONS FROM A C2N2+N2OC_{2}N_{2}+N_{2}O FLAME

$^{\S}$ Aeronautical and Astronautical Engineering Department, The Ohio State University, Columbus, Ohio, 43210. $^{\dag}$ Laboratory of Molecular Spectroscopy and Infrared Studies, Department of Physics. The Ohio State University, Columbus, Ohio, 43210.Author Institution: The Ohio State UniversityThe $C_{2}N_{2}+N_{2}O$ flame is a remarkable source. It is very rich in molecular emissions. The entire visible and ultraviolet regions show well developed electronic bands of the CN, NO and $C_{2}$ molecules. The source, being intense, can be used very successfully with high resolution spectrographs. The emissions in the infrared region are particularly unique. We have not observed any continuum in the infrared. An intense emission was recorded with a grating in the region 4-5 microns. About 400 rotational lines have been measured in this infrared band. A discussion will be presented of all the electronic and infrared emission bands observed with this source