Accession Number : ADA288551

Title :   Soot Particle Density Determination from a Laser Extinction Multipass Technique.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Glaros, Gregory E.

PDF Url : ADA288551

Report Date : SEP 1994

Pagination or Media Count : 46

Abstract : Methods of measuring soot particle densities have been of interest for several decades. Plume signature determination of both rocket and air-breathing engines is of concern when applied to pollution and theater missile ballistic defense strategies. Application of non-intrusive traditional techniques employing Bouguer's law relied on Sauter mean diameter statistical deviation and the probability density function in order to compensate for the ambiguities present in the extension of classical Mie theory. Our investigation developed an apparatus which will determine soot particle densities by measuring extinction from absorption of light energy transmitted through an exhaust plume. The method used was a two-pass technique using an optical phase conjugator (OPC) which returned the non-absorbed portion of light energy. When the apparatus was used with a retroreflector, it produced accurate results but did not compensate for thermal blooming or beam steering. Characteristics of a photorefractive crystal used in the QPC process allowed for the return of an incident beam corrected for aberrations. Although the OPC returned the phase conjugate of the incident beam its size precluded the return of all of the transmitted data because data was lost on the blossomed beam.

Descriptors :   *SOOT, *EXHAUST PLUMES, EXTINCTION, LIGHT SCATTERING, OPTICAL PROPERTIES, POLARIZATION, ENERGY, RETROREFLECTORS, THESES, PARTICLE SIZE, LASER BEAMS, PROBABILITY DENSITY FUNCTIONS, MIE SCATTERING, OPTICAL ANALYSIS, AIR BREATHING ENGINES, ABSORPTION CROSS SECTIONS, BEAM STEERING, ARGON LASERS, POLLUTION, THERMAL BLOOMING, BARIUM TITANATES, PHOTOREFRACTIVE MATERIALS, HELIUM NEON LASERS.

Subject Categories : Combustion and Ignition
      Lasers and Masers
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE