H204 ANALYSIS OF TURBULENT FLOW AND DISINTEGRATION CHARACTERISTICS FEATURING THE COUNTER-SWIRL PNEUMATIC NOZZLE(Bubble behavior)

概要

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The droplet diameters and the turbulent characteristics in a counterflowing internal mixing pneumatic nozzle was mainly focused. The measurements were made using a Phase Doppler Particle Analyzer under the different air pressures. The nozzle with eight tangential-drilled holes at an angle of 15° to the central axis has been designed. The spatial distributions of velocities, turbulence intensities, droplet diameters and volume fluxes were quantitatively analyzed. The results indicate that the stronger axial momentum caused the less dispersion radially, and that axial fluctuating velocities were substantially higher than the radial and the tangential ones. This implies that the disintegration process is enhanced with the higher air pressure. The larger droplets were detected near the spray centerline at the upstream while the smaller ones were generated at the downstream, featuring the internal mixing counter-swirl pneumatic nozzle. This was attributed to the lower rates of spherical particles at upstream which were not subject to instantaneous breakup. However, substantial increases in SMD from the central part toward spray periphery were understandable in the downstream regions.
一般社団法人日本機械学会の論文
2000-10-01