Experimental investigation of turbulence modulation in particle-laden coaxial jets by Phase Doppler Anemometry

• Published in: Experimental thermal and fluid science Vol. 33; no. 3; pp. 517 - 526
• Main Authors: Mergheni, M.A., Sautet, J.C., Godard, G., Ben Ticha, H., Ben Nasrallah, S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01-03-2009; Elsevier
• Subjects: AXIAL SYMMETRY; DISTRIBUTION; ENGINEERING; Exact sciences and technology; EXPERIMENTAL DATA; Flow field measurement; FLUCTUATIONS; Fluid dynamics; Fundamental areas of phenomenology (including applications); GASES; GLASS; Instrumentation for fluid dynamics; JETS; MODULATION; Multiphase and particle-laden flows; Nonhomogeneous flows; PARTICLES; Phase Doppler Anemometry; Physics; REYNOLDS NUMBER; SIZE; SLIP VELOCITY; SPHERES; TURBULENCE; Turbulence modulation; Turbulent flows, convection, and heat transfer; Two-phase coaxial jet; TWO-PHASE FLOW; Turbulence modulation; Flow field measurement; Phase Doppler Anemometry; Two-phase coaxial jet; Test facilities; Turbulent flow; Particle suspension; Experimental study; Anemometry; Coaxial jet; Phase velocity; Particle size distribution; Simultaneous measurement
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/j.expthermflusci.2008.11.004

The effect of solid particles on the flow characteristics of axisymmetric turbulent coaxial jets for two flow conditions was studied. Simultaneous measurements of size and velocity distributions of continuous and dispersed phases in a two-phase flow are presented using a Phase Doppler Anemometry (PDA) technique. Spherical glass particles with a particle diameter range from 102 to 212
μm were used in this two-phase flow, the experimental results indicate a significant influence of the solid particles and the Re on the flow characteristics. The data show that the gas phase has lower mean velocity in the near-injector region and a higher mean velocity at the developed region. Near the injector at low Reynolds number (Re
=
2839) the presence of the particles dampens the gas-phase turbulence, while at higher Reynolds number (Re
=
11
893) the gas-phase turbulence and the velocity fluctuation of particle-laden jets are increased. The particle velocity at higher Reynolds number (Re
=
11
893) and is lower at lower Reynolds number (Re
=
2839). The slip velocity between particles and gas phase existed over the flow domain was examined. More importantly, the present experiment results suggest that, consideration of the gas characteristic length scales is insufficient to predict gas-phase turbulence modulation in gas-particle flows.