Abstract
The present study investigates experimentally the effects of the droplet diameter, its velocity, the surface roughness and thermal conductivity on the direct contact of droplet with the hot surface. Cylindrical blocks made of SUS304 and Brass with different roughness, Ra0.04, 0.2, 3, 10 were used. The droplet diameter and velocity were independently controlled in ranges of 300-700μm and 1.0-4.0m/s, respectively. The behavior of droplet during the collision with hot surface was observed with the high-speed camera in the range of surface temperature from 600℃ to room temperature. The experimental results show that the solid-liquid contact time decreases with the increase in droplet velocity and it increases when Ra=10. It is also found that maximum spread of droplet over the surface increases with the increase in droplet velocity.
