高温壁面における液滴の挙動に関する研究 : 第1報,分裂形態と変形挙動について

抄録

Experiment have been carried out on the behavior of the water drop impinging upon a hot surface. The effects provided by the drop diameter, the velocity and the surface temperature on the variations of disintegration patterns and deformation have been studied and experimented quantitatively. Drops were produced by the dripping method and by the impulse jet nozzle which was developed newly and consisted of a cylindrical piezoelectric ceramics. According to the results, the critical Weber number of the disintegration pattern keeps a constant at the hot surface temperature of more than 300°C but this decreases approaching the Leidenfrost point and the deformation of the small drop, of one less than approximately 300μm in diameter, is smaller than that of the larger one. Furthermore, the maximum spreading time to the contacting time t_dsmax/τ shows constant, even if the diameter and/or the velocity change, and its value is approximately 0.25-0.3.