Effect of particle polydispersity on particle concentration measurement by using laser Doppler anemometry

• Published in: Experimental thermal and fluid science Vol. 31; no. 8; pp. 839 - 847
• Main Authors: Ayrancı, Işıl, Pinguet, Guillaume, Escudié, Dany, Selçuk, Nevin, Vaillon, Rodolphe, André, Frédéric
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-08-2007; Elsevier Science; Elsevier
• Subjects: Engineering Sciences; Exact sciences and technology; Fluid dynamics; Fundamental areas of phenomenology (including applications); Instrumentation for fluid dynamics; Laminar; LDA; Mechanics; Multiphase and particle-laden flows; Nonhomogeneous flows; Particle number density; Particle-laden jet; Physics; Thermics; Turbulent; LDA; Turbulent; Particle number density; Particle-laden jet; Laminar; Test facilities; Turbulent flow; Vertical jet; Particle suspension; Experimental study; Concentration measurement; Laminar flow; Two-phase flow; Laser Doppler anemometers; Air jet; Polydispersed particle
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/j.expthermflusci.2006.03.031

Measurement of particle concentration by laser Doppler anemometry (LDA) is studied on a vertical air jet seeded by a powder disperser with controlled particle and air flow rates. Particle arrival rate is utilized to retrieve particle number densities from conventional LDA operation. The effect of polydisperse nature of the particles is assessed. Comparisons between measured and estimated particle number densities suggest that only a certain portion of the particle population with a particle size to fringe spacing ratio around unity can be detected. Results indicate that reliable measurement of absolute particle concentration is possible for a particle population of narrow size distribution with an average diameter equivalent to fringe spacing. Present number density measurement technique which is useful for practical purposes with conventional LDA systems is found to yield physically reasonable profiles in both laminar and turbulent regimes.