Effects of weber number and surface temperature on the boiling and spreading characteristics of impinging water droplets

摘要

In the present work, the effects of Weber number and surface temperature upon the droplet impingement behavior and boiling characteristics have been experimentally studied. High speed photography (up to 8000 frames per second) has been employed to visualize the interface interactions. An experimental apparatus is designed and fabricated to deliver constant size droplets to a heated copper surface. The Weber number and the surface temperature are varied to determine their effects upon the boiling characteristics. The surface temperature range is 25°C to 350°C and the Weber number is varied from 10 to 58. A high-speed digital camera is utilized in capturing this dynamic. The droplet characteristic during droplet levitation has been classified into four types; levitation after several advance and recoil cycles, levitation after first recoil, disintegration after first recoil, disintegration after impact. The maximum spread diameter is also compared with three established correlations from literature.