The Phase Doppler Method: Analysis, performance evaluations, and applications

Abstract

This review of the recent developments in the phase Doppler method provides information on the advances made to the method and delineates some potential error sources. Methods used to eliminate these potential error sources are also discussed. It is shown through comparison to the Lorenz-Mie theory and the GLMT that the geometrical optics theory offers a reliable and efficient computational tool for the analysis of the light scattering with the phase Doppler method. The geometrical optics theory was then used to optimize the measurement parameters in the system designs and a significant reduction in the measurement uncertainty was realized. Limitations on the particle concentrations in which the instrument will operate reliably are also addressed. A brief discussion of the instrumentation and, in particular, the signal processing is presented. The advantages in using the Fourier transform approach are discussed. As a demonstration of the capabilities of the instrument, several performance tests were reviewed and examples of the application to spray combustion and turbulent dispersion of particles are given.

The Influence of Macroscopic Elongational Flow on Dispersion Processes in Agitated Tanks

“…For the definition of these angles see Fig. 1 or [13]. The measurement range of the PDA system goes up to 812 lm.…”

Airborne Phase Doppler Interferometry for Cloud Microphysical Measurements

“…Droplets smaller than 300 µm are generally nearly perfect spheres, and maximum uncertainty of ∼2% and ∼10% due to asphericity may be expected for drops of 1 mm and 2 mm, respectively (Pruppacher and Klett 1997). There are other issues once drops become very large relative to the sample volume diameter, such as the possibility of reflection becoming significant relative to refraction, although such issues can be dealt with (e.g., Bachalo 1994). It is straightforward to produce large beam diameters to optimize measurement of large drops, with the trade-off of increasing the size of the smallest measurable drop.…”

Laboratory and numerical modeling of the formation of superfog from wildland fires

“…As discussed in Section 2, the liquid water content and the visibility depend on both the number concentration and the size distribution of droplets. A TSI [35] Phase Doppler Particle Analyzer (PDPA) was used to measure the size distribution and number concentration of droplets formed through condensation in our test chamber.…”