Abstract
This paper presents experimental investigations of effects of the surface roughness, impinging velocity, and diameter of a droplet on the cooling rate in water spray cooling. The sample surface used is SUS304 cylinder with different roughness, Ra 0.04 (Mirror), 0.2, 3, and 10. The droplet diameter and velocity are independently controlled in ranges of 300-700 μm and 1.0-5.0 m/s, respectively. The cooling rate increases with decrease in droplet diameter when the flow rate of water is constant. The cooling rate also increases with impinging velocity and surface roughness. The effect of the velocity difference arises in the film boiling region.
