Characteristics of Mean Droplet Size Produced by Spinning Disk Atomizers

Abstract

Characteristics of mean droplet size of spray produced by spinning disk atomizers were experimentally investigated. The phase-doppler particle analyzer (PDPA) was used to measure the droplet size of water spray in the downstream distance along the spray trajectory. Effects of various operating conditions on the mean diameter had been studied. The studied variables were: the rotational speed in the range of 838 to 1677 rad/s (8,000–16,000 rpm), the liquid flow rate in the range of 0.56 to 2.8 × 10−6 m3 /s (2–10 L/h), the disk diameter in the range of 0.04 to 0.12 m, and the downstream tangential distance along the spray trajectory of up to 0. 24 m. The Sauter mean diameter (d32 ) was used to represent the mean of generated spray droplet sizes. The results indicated that the Sauter mean diameter can be correlated with dimensionless groups, such as the Reynolds number, Weber number, flow coefficient, and the ratio of downstream distance to disk diameter. Based on this correlation, it was found that the Sauter mean diameter (d32 ) increases as the downstream tangential distance, and liquid flow rate increase. Similarly, a decrease of rotational speed and disk diameter results in an increase in the Sauter mean diameter (d32 ). A comparison between the developed correlation and correlations obtained by other researchers has been presented and discussed in detail.