Accession Number : ADP008950

Title :   Laser Light Sheet Studies by Digital Image Processing Compared to Particle Concentration Measurements by PDA in Pneumatic Conveying,

Corporate Author : ERLANGEN-NUERNBERG UNIV (GERMANY F R) LEHRSTUHL FUER STROEMUNGSMECHANIK

Personal Author(s) : Huber, N. ; Qiu, H. -H. ; Sommerfeld, M.

Report Date : 23 JUL 1992

Pagination or Media Count : 6

Abstract : The laser-light sheet method combined with digital image processing was applied to characterize the degree of non-uniformity of the particle concentration distribution in pneumatic conveying. With the light sheet intersecting the pipe cross-section at an angle of about 45 deg it was possible to obtain a whole field picture of the light intensity scattered by the particles. With a simplified theory it was possible to relate the scattered light power to the particle concentration distribution in different pipe elements (i.g. horizontal and vertical pipe). Addtionally, informations on the particle velocity and the size distribution could be obtained by phase-Doppler anemometry (PDA) which allowed single point measurements along a line through the pipe cross-section. Moreover, accurate particle concentration measurements were performed by PDA with a recently developed method where the logarithmic mean value of the signal amplitudes is used to determine the particle size-dependent cross-section of the measurement volume. The comparison of the particle concentration obtained by PDA with those evaluated from the digitized images of the light power scattered by the particles in one cross-section showed good agreement. (Author)

Descriptors :   *PIPE FLOW, *LASER ANEMOMETERS, PNEUMATIC EQUIPMENT, DIAGNOSIS(GENERAL), OPTICAL PROCESSING, CROSS SECTIONS, GERMANY.

Subject Categories : Fluid Mechanics
      Lasers and Masers
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE