Accession Number:

ADA167109

Title:

A Linear Array for Rayleigh Scattering.

Descriptive Note:

Final rept. 1 Sep 83-31 Jan 85,

Corporate Author:

CALIFORNIA UNIV BERKELEY DEPT OF MECHANICAL ENGINEERING

Personal Author(s):

Report Date:

1985-06-11

Pagination or Media Count:

27.0

Abstract:

Gas density under combustion conditions can be obtained by measuring the intensity of the molecular Rayleigh scattering of light from a laser beam. A system which obtains an essentially continuous record of the density along a length of the laser beam is described. The temperature and degree of combustion can thus be determined for a number of interesting combustion configurations, which will ultimately lead to a better description and understanding of combustion flow flame field phenomena. An image of Rayleigh scattered light from the combustion region is projected onto a monolithic self scanning linear photodiode array by means of a lens, bandpass filter, slit, image intensifier, and fiber optic reducer. The video output of the linear array is digitized and stored, creating a space-time map of the density which can be visualized and manipulated as an image. Analysis of these images by image processing techniques gives qualitative and quantitative information about such features of the combustion zone as flame wrinkling and periodicity, flame thickness and continuity, and other structural and time dependent properties in the combustion region. Following a brief introduction, the components are described, the system performance characteristics are discusssed, and an example of a processed image from a simple turbulent flame is presented. Keywords Rayleigh scattering Premixed turbulent flames Laser imaging.

Subject Categories:

  • Physical Chemistry
  • Lasers and Masers

Distribution Statement:

APPROVED FOR PUBLIC RELEASE