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Size of the Detection Area of a Phase‐Doppler Anemometer for reflecting and refracting particles
Author(s) -
Schöne Frank,
Bauckhage Klaus,
Wriedt Thomas
Publication year - 1994
Publication title -
particle and particle systems characterization
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.877
H-Index - 56
eISSN - 1521-4117
pISSN - 0934-0866
DOI - 10.1002/ppsc.19940110409
Subject(s) - weighting , particle size , anemometer , phase (matter) , optics , particle (ecology) , perpendicular , measure (data warehouse) , dispersity , particle size distribution , materials science , physics , mechanics , mathematics , turbulence , acoustics , computer science , geometry , chemistry , geology , oceanography , quantum mechanics , database , polymer chemistry
Measurements of particle size distributions in multi‐phase flows with a phase‐Doppler anemometer yield incorrect results if polydisperse particles are investigated. For weighting biased size distributions, different in situ methods, requiring the size of the detection area, are known, but all of these weighting procedures are restricted to very small measuring volumes if off‐axis instrument configurations are considered. Moreover, the weighting functions have some disadvantages in the case of poor statistics in single size classes or the results are not suitable for determining the size of the detection area for particles which are larger than the beam waist. Therefore, the intention in this work was to measure the size of the detection area for different kinds of monodisperse particles, different instrument configurations and varied instrument sensitivities experimentally and to develop an improved weighting procedure that copes with the above difficulties. The application of the results obtained from the investigations with monodisperse particles to measured particle size distributions and volume flux densities of polydisperse water droplets in a spray cone of an atomizer confirms the applicability of this weighting procedure. It is still restricted to directed flows, perpendicular to the fringes.