Dynamic behavior and heat transfer characteristics of impinging droplets onto high temperature plate

Dynamic behavior and heat transfer characteristics of impinging droplets onto high temperature plate

Lee, C.H.
Kim, D.Y.
Kim, H.D.
Kim, K.C.

2013-07-03

Dynamic behaviour and heat transfer characteristics of impinging droplets on a hot surface were studied experimentally. De-ionized water droplet was made through a 31G injection needle and the droplet size was 2 mm. A sapphire plate was heated up to 300ºC by a hotplate. A high speed camera was used for visualization, and the frame rate was 4000 fps. Weber number was changed from 0.91 to 117.54 by changing initial height of droplet from 10mm to 210 mm. Hydrophobic characteristics was observed when the temperature of hot surface was over Leidenfrost point. Dynamic behaviour was strongly depended on Weber number and splashing phenomena occurred when the Weber number was higher than 50. Micro-explosion was observed at high Weber number with Leidenfrost condition. From the PIV measurement, it was found that the exploded droplets have considerably high speed compared to the impinging velocity. Maximum heat transfer was coincided with nucleate boiling phase after the droplet impingement.

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Conference proceedings

conference paper

(c) 2013 Lee, C.H.; Kim, D.Y.; Kim, H.D.; Kim, K.C.