Thumbnail
Access Restriction
Open

Author Damaschke, N. ♦ Nobach, H. ♦ Semidetnov, N. ♦ Tropea, C.
Source CiteSeerX
Content type Text
File Format PDF
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Backscatter Particle Sizing ♦ Cross-sectional Area Difference Method ♦ Cross Sectional Area Difference Method ♦ Burst-length Statistic ♦ Particle Size ♦ Modulated Part ♦ Period De-pends ♦ Inversion Routine ♦ Intensity Diameter Relation ♦ First-order Refraction ♦ Maximum Intensity ♦ Small Par-ticles ♦ Main Problem ♦ Diameter Distribution ♦ Laser Doppler Signal ♦ Cross-sectional Area Difference Technique ♦ Aperture Design ♦ Commercial Laser Doppler Equipment ♦ Monotonic Relation ♦ Burst Signal ♦ Particle Size Distribution ♦ Commercial Backscatter ♦ Doppler System ♦ Possible Extension ♦ Normal Laser Doppler System ♦ Doppler Signal ♦ Numerical Calculation ♦ Monotonic Intensity Diameter Relation ♦ Burst Length ♦ Statistical Manner ♦ Scattered Intensity ♦ Software Comp Onent
Abstract This paper reports on possible extensions of the cross-sectional area difference method for sizing particles in backscatter by using commercial laser Doppler equipment. The cross-sectional area difference method was introduced by Albrecht et al. (1993) and Borys (1996). It uses signals from a normal laser Doppler system to estimate the particle size distribution in a statistical manner. The maximum intensity of a burst signal and therefore the burst length or the number of periods de-pends on the particle size. In the mean larger particles generate signals of higher amplitude and longer duration. The technique is based on the inversion of the particle generated burst-length statistics to the diameter distribution. The monotonic relation between particle size and scattered intensity of the modulated part of a laser Doppler signal is one pre-requisite for the success of this inversion routine. The technique was successfully applied (Borys 1996) to small par-ticles (x < 1) and for larger particles at forward scattering angles with monotonic intensity/diameter relation for first-order refraction. The cross-sectional area difference technique operates just with laser Doppler signals. Therefore it could be attractive to use a commercial backscatter laser Doppler system for velocity and particle sizing only by adding a software comp onent for processing the burst-length statistics. The main problem of the cross-sectional area difference method in backscatter is the fluctuations of the intensity/diameter relation. The paper will present numerical calculations for aperture design. It
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research
Education Level UG and PG ♦ Career/Technical Study
Learning Resource Type Article