Droplet turbulence in annular dispersed flow

Droplet size and fluctuate droplet velocities in annular dispersed and dispersed flows, which were formed using air and water at atmospheric pressure and room temperature, were measured using a PDPA (Phase Doppler Particle Analyzer) system. Though the fluctuate droplet velocity in a radial direction in the annular flow was larger than that in the dispersed flow, both fluctuate droplet velocities decreased with increasing the droplet size. The dependence of the fluctuate velocity ratio of droplet to air on the droplet size was almost the same in both flow patterns. (author)