Effects of Droplet Temperature on Heat Transfer During Collision on a Heated Wall Above the Leidenfrost Temperature
Leidenfrost 온도 이상의 가열 벽면과 충돌 시 열전달에 대한 액적 온도의 영향

Junseok Park, Hyungdae Kim
2016 Journal of ILASS-Korea  
This study experimentally investigated the effects of droplet temperature on the heat transfer characteristics during collision of a single droplet on a heated wall above the Leidenfrost temperature. Experiments were performed by varying temperature from 40 to 100 o C while the collision velocity and wall temperature were maintained constant at 0.7 m/s at 500 o C, respectively. Evolution of temperature distribution at the droplet-wall interface as well as collision dynamics of the droplet were
more » ... f the droplet were simultaneously recorded using synchronized high-speed video and infrared cameras. The local heat flux distribution at the collision surface was deduced using the measured temperature distribution data. Various physical parameters, including residence time, local heat flux distribution, heat transfer rate, heat transfer effectiveness and vapor film thickness, were measured from the visualization data. The results showed that increase in droplet temperature reduces the residence time and increases the vapor film thickness. This ultimately results in reduction in the total heat transfer by conduction through the vapor film during droplet-wall collision. 기호설명 A : 열전달 면적 [m 2 ] Cp : 비열 [J/kg o C] Dd : 액적의 지름 [m] Ed : 액적의 제거 에너지 [J] Emax : 액적이 완전히 증발하는데 필요한 에너지 [J]
doi:10.15435/jilasskr.2016.21.2.78 fatcat:w2lbjqrujzglrf3xrorgejoja4