Study of the mist cooling and droplet dynamics in turbulent flow by using LDA

The schemes which allow the in-situ measurement of droplet size and two components of velocity by the Laser Doppler Anemometer system are presented. The small droplet measurement technique and the large droplet measurement technique are described. The path length correction scheme is explained and the amplitude correction scheme is proposed for small droplet size measurement scheme. A scheme of simultaneous measurement of large droplet size and the two components velocity is developed and verified by the validation experiments. The on-line data acquisition system and the signal processing instrumentation are described. A droplet deposition phenomenon from a turbulent flow on a plate is investigated. The dimensionless deposition coefficient is studied theoretically based on the droplet's frequency response characteristics to the surrounding eddy motion. An investigation was made on the droplet's behavior across the quenched grid spacer. The empirical correlations on the Sauter Mean Diameter and the Fractional Volume of the small droplets are obtained.