Concentration, Velocity, and Particle Size Measurements in Gas-Solid Two-Phase Jets

Abstract

An optical technique was developed and used to measure particle concentration profiles in dense two-phase axisymmetric jets. Gas velocity profiles of the single-phase jet were measured by a pitot probe. Particle size distribution across the jet was measured with isokinetic particle sampling probes. Schlieren photographs of shock waves in the jet were taken to study the influence of particles on shock-wave structure near the exit of the nozzle. The effect of nozzle configuration on the two-phase jet flow was also investigated. The measurements were made by seeding 1,3, and 5% by weight of 24 /xm mean diameter spherical fly ash particles into jets at Mach numbers of 0.2, 0.8, and 1.0. The particle concentration profiles showed that particles concentrate on the axis of the jet at the exit of the nozzle and the profiles are influenced by the seeding rate, the velocity of the jet, and the nozzle configuration. The particle size distribution is homogeneous in the jet. Schlieren photographs of shock waves in the jet showed that the normal shock wave near the exit of the nozzle was convexly curved with the addition of a suspension of particles in the jet.