Size and Velocity Measurements of Spherical Particles in Multiphase Flows and the Prediction of Absolute Particle Concentrations

Bauckhage, Klaus; Flögel, Hans-H.; Schöne, Frank

doi:10.1007/978-1-4757-1983-3_36

Cited by 6 publications

(3 citation statements)

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“…The principles of phase-Doppler anemometry for determining simultaneously velocity and size distributions of suspended spherical particles were first presented by Durst and Zaré [1]. Subsequent contributions to the development of phase-Doppler anemometry, for example [2][3][4] were essential to the development of the technique and the recognition of its capabilities and have essentially assisted the development of commercial instruments. For many significant applications, such instruments provide reliable measurements of spherical particles of known refractive index and diameters exceeding about 5 µm.…”

Section: Introductionmentioning

confidence: 99%

A review of the development and characteristics of planar phase-Doppler anemometry

Durst

Brenn

1997

Meas. Sci. Technol.

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Phase-Doppler anemometry is now a well-established measuring technique for simultaneous measurements of particle velocity, size, flux and concentration and its usefulness has been demonstrated in a wide range of applications to multiphase flows. Since its introduction in 1975, it took until 1980 to re-discover the measuring technique for particle sizing. Moreover, the increased understanding of the influence of the Gaussian intensity distribution in the probe volume of a phase-Doppler anemometer (PDA) revealed an important feature of PDA in a planar configuration, namely the temporal separation of the contributions of two scattering mechanisms, reflection and refraction, to the light received by the photodetectors. This implies the possibility of suppressing measurement errors caused by the mixing of the two modes of scattered light and even makes it possible to perform refractive-index measurements by comparison of the reflective and the refractive phases. In the most recent development of the so-called dual-mode PDA, the planar set-up is one essential part of the system which ensures that an accurate measurement of the particle size and, therefore, of the particulate volume flux is obtained. The present paper reviews the historical development of planar PDA and its capabilities and present applications.

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Section: Introductionmentioning

confidence: 99%

A review of the development and characteristics of planar phase-Doppler anemometry

Durst

Brenn

1997

Meas. Sci. Technol.

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“…For non-intrusive and simultaneous measurements of particle velocity and particle size, phase-Doppler anemometry is a very suitable method (Buuckhuge and Flogel [l], Saffmun et al [2], Buchalo and Houser [3], referring to fundamentals described by Durst and ZurP [4]). This measuring technique yields absolute results of particle size and velocity, but in the case of the prevailing application, i. e. the analysis of multi-phase flows with polydisperse particle collections (Buchalo and Houser [5], Bauckhuge [6], Bauckhuge et al [7]), the measured number distributions of particles sizes are biased in a way that large particles are over-represented in comparison with smaller ones ([2], Bauckhuge et al [8], Suffman [9], Bachulo [lo]). Therefore, a weighting procedure becomes necessary to obtain correct results for the corresponding distributions and for all related flow parameters, such as particle concentration and mass flux density.…”

Section: Introductionmentioning

confidence: 99%

“…The commonly used function for weighting size distributions is the area of detection, being part of the cross-sectional area of the measuring volume. If reflecting particles are measured with the aid of a backscatter PDA, the size of the detection area can be determined very easily value of burst amplitudes (Sommerfeld and Qiu [12]), the maximum burst length, the maximum number of signal periods above a fixed trigger level [8,101 or the mean value of squared burst lengths 191. For a specific weighting procedure, either the burst, generated by only one reference particle with well known diameter do, moving through the centre of the measuring volume, or the bursts of single reference particles in each particle size class di, have to be analysed with respect to their lengths or amplitudes.…”

Section: Introductionmentioning

confidence: 99%

Size of the Detection Area of a Phase‐Doppler Anemometer for reflecting and refracting particles

Schöne

Bauckhage

Wriedt

1994

Part & Part Syst Charact

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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.

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New Generation of Phase‐Doppler Instruments for particle velocity, size and concentration measurements

Aizu¹,

Domnick²,

Durst³

et al. 1994

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Phase-Doppler anemometry (PDA) is applied for particle size, velocity and concentration measurements in two-phase or multi-phase flows of ever increasing complexity. For accurate measurements the experimenter must be provided with software and hardware which permit an optimal layout of the PDA optics for a given application, reliable detection of signals over a wide particle diameter range, accurate determination of particle concentration and precise discrimination between particles of different composition. Recent work at LSTM, Erlangen, has been directed to developing a complete PDA package for the above purposes. Progress in this direction is summarized in this paper. This paper summarizes efforts to improve the phase-Doppler technique in terms of the measurement accuracy, the handling of the system and the field of applications. The work has led to new programs based on Mie scattering for initial system layout and to new optical and electronic developments.Q(X) -+ min =$ Q(X*) XEG has to be fulfilled, where X denotes the optical parameters to be determined, G is the group of allowed parameters and X * is the optimized optical parameters.

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Size and Velocity Measurements of Spherical Particles in Multiphase Flows and the Prediction of Absolute Particle Concentrations

Cited by 6 publications

References 1 publication

A review of the development and characteristics of planar phase-Doppler anemometry

A review of the development and characteristics of planar phase-Doppler anemometry

Size of the Detection Area of a Phase‐Doppler Anemometer for reflecting and refracting particles

New Generation of Phase‐Doppler Instruments for particle velocity, size and concentration measurements

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